{"id":1367,"date":"2019-02-08T21:10:03","date_gmt":"2019-02-08T12:10:03","guid":{"rendered":"https:\/\/www.bold.ne.jp\/engineer-club\/?p=1367"},"modified":"2025-10-06T17:00:09","modified_gmt":"2025-10-06T08:00:09","slug":"java-string","status":"publish","type":"post","link":"https:\/\/www.bold.ne.jp\/engineer-club\/java-string","title":{"rendered":"\u3053\u308c\u3060\u3051\u899a\u3048\u3088\u3046! \u521d\u5fc3\u8005\u5fc5\u898b\u3001Java\u306eString\u306e\u57fa\u672c\u3068\u5fdc\u7528\u3092\u3054\u7d39\u4ecb"},"content":{"rendered":"<p><strong>String\u3068\u306f\u6587\u5b57\u304c\u96c6\u307e\u3063\u3066\u3067\u304d\u305f\u300c\u6587\u5b57\u5217\u300d\u306e\u3053\u3068\u3067\u3001Java\u3067\u6271\u3048\u308b\u30c7\u30fc\u30bf\u306e\u4e2d\u3067\u306f\u57fa\u672c\u7684\u306a\u3082\u306e\u306e\u4e00\u3064\u3067\u3059\u3002<\/strong><\/p>\n<p>\u6587\u5b57\u5217\u3001\u3064\u307e\u308a<span>String<\/span>\u3092\u4f7f\u308f\u306a\u3044<span>Java<\/span>\u30d7\u30ed\u30b0\u30e9\u30e0\u306f\u306a\u3044\u3068\u8a00\u3063\u3066\u3082\u3044\u3044\u3067\u3057\u3087\u3046\u3002<\/p>\n<p>\u3067\u3059\u304b\u3089\u3001<span>String<\/span>\u306e\u7279\u5fb4\u3084\u4e0a\u624b\u306a\u4f7f\u3044\u65b9\u3092\u77e5\u3063\u3066\u3044\u308b\u3068\u3001\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u304c\u3068\u3066\u3082\u3084\u308a\u3084\u3059\u304f\u306a\u308b\u306e\u3067\u3059\u3002<br \/>\n\u4e0a\u624b\u306a\u30d7\u30ed\u30b0\u30e9\u30e0\u306f\u3001\u30d7\u30ed\u30b0\u30e9\u30e0\u4e2d\u3067\u306e<span>String<\/span>\u306e\u4f7f\u3044\u65b9\u3082\u300c\u307b\u307b\u3045<span>\u2026<\/span>\u300d\u3068\u8a00\u3044\u305f\u304f\u306a\u308b\u307b\u3069\u4e0a\u624b\u306a\u3082\u306e\u3067\u3059\u3088\u3002<\/p>\n<p>\u3053\u306e\u8a18\u4e8b\u3067\u306f\u3001<span>Java<\/span>\u3067\u306e<strong><span class=\"f-marker-p\">String\u304c\u3069\u3046\u3044\u3046\u3082\u306e\u304b<\/span><\/strong>\u3001<strong><\/strong><span class=\"f-marker-p\"><strong>\u3069\u3046\u3044\u3046\u98a8\u306b\u4f7f\u3048\u308b\u3082\u306e\u304b<\/strong><\/span>\u3092\u304a\u4f1d\u3048\u3057\u307e\u3059\u3002<\/p>\n<p>\u305d\u3082\u305d\u3082<span>String<\/span>\u3068\u306f\u306a\u3093\u3060\u308d\u3046\u3068\u3044\u3046\u6240\u304b\u3089\u3001<span>String<\/span>\u3092\u4f7f\u3046\u4e0a\u3067\u306f\u6b20\u304b\u305b\u306a\u3044\u57fa\u672c\u7684\u306a\u30e1\u30bd\u30c3\u30c9\u306e\u4f7f\u3044\u65b9\u307e\u3067\u5e83\u304f\u3054\u7d39\u4ecb\u3057\u307e\u3059\u3057\u3001\u6700\u8fd1\u306e<span>Java<\/span>\u3067\u306f<span>String<\/span>\u304c\u3069\u3093\u306a\u306b\u4fbf\u5229\u306b\u306a\u3063\u305f\u304b\u3082\u3001\u3057\u3063\u304b\u308a\u5206\u304b\u308a\u307e\u3059\u3088<span>!!<\/span><\/p>\n<p>\u203b\u3053\u306e\u8a18\u4e8b\u306e\u30b5\u30f3\u30d7\u30eb\u306f\u3001<span>Java 11<\/span>\u306e\u74b0\u5883\u3067\u52d5\u4f5c\u78ba\u8a8d\u3057\u3066\u3044\u307e\u3059<\/p>\n<div id=\"toc_container\" class=\"no_bullets\"><p class=\"toc_title\">\u76ee\u6b21<\/p><ul class=\"toc_list\"><li><a href=\"#JavaString\">\uff11\uff0e\u3010Java\u3011String\u3068\u306f\u3069\u3093\u306a\u3082\u306e\u304b<\/a><ul><li><a href=\"#-String82208220\">\uff11-\uff11\uff0eString\u3068\u306f\u6587\u5b57\u304c\u96c6\u307e\u3063\u305f&#8220;\u6587\u5b57\u5217&#8220;\u306e\u3053\u3068<\/a><\/li><li><a href=\"#-JavaString\">\uff11-\uff12\uff0eJava\u306e\u6587\u5b57\u5217\u306fString\u30af\u30e9\u30b9\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9<\/a><\/li><li><a href=\"#-String82208221\">\uff11-\uff13\uff0eString\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u4f5c\u308b\u306b\u306f\u3001\u6587\u5b57\u5217\u3092&#8220;&#8221;\u3067\u56f2\u3046<\/a><\/li><li><a href=\"#-String\">\uff11-\uff14\uff0eString\u3068\u30a4\u30f3\u30c7\u30c3\u30af\u30b9<\/a><\/li><li><a href=\"#-8220string8221\">\uff11-\uff15\uff0e\u3010\u53c2\u8003\u3011\u306a\u305c&#8220;string&#8221;\u3068\u547c\u3070\u308c\u308b\u306e\u304b?<\/a><\/li><\/ul><\/li><li><a href=\"#String\">\uff12\uff0e\u3010\u57fa\u672c\u3011String\u3092\u4f7f\u3063\u3066\u307f\u308b<\/a><ul><li><a href=\"#-length\">\uff12-\uff11\uff0e\u6587\u5b57\u306e\u6570\u3092\u8abf\u3079\u308blength<\/a><\/li><li><a href=\"#-substring\">\uff12-\uff12\uff0e\u90e8\u5206\u6587\u5b57\u5217\u3092\u5207\u308a\u51fa\u3059substring<\/a><\/li><li><a href=\"#i\">\uff12-\uff13\uff0e\u6587\u5b57\u5217\u3092\u542b\u3080\u304b\u8abf\u3079\u308b<\/a><\/li><li><a href=\"#i-2\">\uff12-\uff14\uff0e\u6587\u5b57\u5217\u3092\u5909\u63db\u3059\u308b<\/a><\/li><li><a href=\"#i-3\">\uff12-\uff15\uff0e\u6587\u5b57\u5217\u3092\u7e4b\u3052\u308b\u30fb\u5206\u5272\u3059\u308b<\/a><\/li><li><a href=\"#i-4\">\uff12-\uff16\uff0e\u6587\u5b57\u5217\u3092\u6bd4\u8f03\u3059\u308b<\/a><\/li><\/ul><\/li><li><a href=\"#String-2\">\uff13\uff0e\u3010\u5fdc\u7528\u3011String\u3092\u6d3b\u7528\u3059\u308b\u305f\u3081\u306b\u305c\u3072\u77e5\u3063\u3066\u304a\u304d\u305f\u3044\u3053\u3068<\/a><ul><li><a href=\"#-String-2\">\uff13-\uff11\uff0eString\u306f\u81ea\u5206\u81ea\u8eab\u306e\u6587\u5b57\u5217\u3092\u5909\u3048\u3089\u308c\u306a\u3044<\/a><\/li><li><a href=\"#-null82208221\">\uff13-\uff12\uff0enull\u3068&#8220;&#8221;\u306f\u9055\u3046\u3082\u306e<\/a><\/li><li><a href=\"#-String-3\">\uff13-\uff13\uff0eString\u3068\u4ed6\u306e\u30af\u30e9\u30b9\u3092\u5909\u63db\u3059\u308b<\/a><\/li><li><a href=\"#-StringBuilder\">\uff13-\uff14\uff0eStringBuilder\u3067\u6587\u5b57\u5217\u3092\u7e4b\u3052\u308b<\/a><\/li><li><a href=\"#-String-4\">\uff13-\uff15\uff0e\u6587\u5b57\u30b3\u30fc\u30c9\u3068String<\/a><\/li><\/ul><\/li><li><a href=\"#StringJava_811\">\uff14\uff0e\u3010\u4fbf\u5229\u3011\u3053\u3053\u6700\u8fd1\u306eString\u4e8b\u60c5(Java 8\uff5e11)<\/a><ul><li><a href=\"#-StringjoinJava_8\">\uff14-\uff11\uff0eString\u3092\u7e4b\u3052\u308bjoin\u3010Java 8\uff5e\u3011<\/a><\/li><li><a href=\"#-StreamcharsJava_9\">\uff14-\uff12\uff0e\u6587\u5b57\u306eStream\u3092\u53d6\u5f97\u3059\u308bchars\u3010Java 9\uff5e\u3011<\/a><\/li><li><a href=\"#-Java_9String\">\uff14-\uff13\uff0e\u3010\u767a\u5c55\u3011Java 9\u3067\u306eString\u95a2\u9023\u5909\u66f4<\/a><\/li><li><a href=\"#-linesJava_11\">\uff14-\uff14\uff0e\u6539\u884c\u30b3\u30fc\u30c9\u3067\u5206\u5272\u3059\u308blines\u3010Java 11\uff5e\u3011<\/a><\/li><li><a href=\"#-isBlankJava_11\">\uff14-\uff15\uff0e\u7a7a\u767d\u3057\u304b\u306a\u3044\u304b\u3092\u78ba\u8a8d\u3059\u308bisBlank\u3010Java 11\uff5e\u3011<\/a><\/li><li><a href=\"#-stripstripLeadingstripTrailingJava_11\">\uff14-\uff16\uff0e\u5168\u89d2\u7a7a\u767d\u3082\u524a\u9664\u3059\u308bstrip\/stripLeading\/stripTrailing\u3010Java 11\uff5e\u3011<\/a><\/li><li><a href=\"#-StringrepeatJava_11\">\uff14-\uff17\uff0eString\u3092\u7e70\u308a\u8fd4\u3059repeat\u3010Java 11\uff5e\u3011<\/a><\/li><\/ul><\/li><li><a href=\"#i-5\">\uff15\uff0e\u3055\u3044\u3054\u306b<\/a><\/li><\/ul><\/div>\n<h2><span id=\"JavaString\">\uff11\uff0e\u3010Java\u3011String\u3068\u306f\u3069\u3093\u306a\u3082\u306e\u304b<\/span><\/h2>\n<h3><span id=\"-String82208220\">\uff11-\uff11\uff0eString\u3068\u306f\u6587\u5b57\u304c\u96c6\u307e\u3063\u305f<span>&#8220;<\/span>\u6587\u5b57\u5217<span>&#8220;<\/span>\u306e\u3053\u3068<\/span><\/h3>\n<p>Java\u306e<span>String<\/span>\u3068\u306f\u6587\u5b57\u304c\u96c6\u307e\u3063\u305f\u30e2\u30ce\u306e\u3053\u3068\u3067\u3001\u3044\u308f\u3086\u308b\u6587\u5b57\u5217\u3067\u3059\u3002<span>Java<\/span>\u3067\u306f\u3001<span>A<\/span>\u3001<span>B<\/span>\u3001<span>C<\/span>\u3001\u3042<span>\u2026<\/span>\u306e\u3088\u3046\u306a\u6587\u5b57\u4e00\u3064\u3092\u3001\u57fa\u672c\u30c7\u30fc\u30bf\u578b\u306e<span>char<\/span>\u4e00\u3064\u3067\u8868\u3057\u307e\u3059\u3088\u306d\u3002<span>String<\/span>\u306f\u305d\u3093\u306a\u6587\u5b57\u304c\u305f\u304f\u3055\u3093\u96c6\u307e\u3063\u305f\u30e2\u30ce\u3067\u3059\u3002<\/p>\n<h3><span id=\"-JavaString\">\uff11-\uff12\uff0eJava\u306e\u6587\u5b57\u5217\u306f<span>String<\/span>\u30af\u30e9\u30b9\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9<\/span><\/h3>\n<p>Java\u306e\u6587\u5b57\u5217\u306f\u3001<span>String<\/span>\u30af\u30e9\u30b9\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3067\u3059\u3002\u30af\u30e9\u30b9\u3067\u3059\u304b\u3089\u3001\u6587\u5b57\u5217\u3068\u3044\u3046\u5024\u3068\u3001\u30e1\u30bd\u30c3\u30c9\u3068\u3044\u3046\u632f\u308b\u821e\u3044\u3092<span>String<\/span>\u81ea\u8eab\u304c\u6301\u3063\u3066\u3044\u307e\u3059\u3002\u3067\u3059\u306e\u3067\u3001<span>Java<\/span>\u3067\u306e\u6587\u5b57\u5217\u64cd\u4f5c\u306f\u3001\u6587\u5b57\u5217\u305d\u306e\u3082\u306e\u306b\u50cd\u304d\u304b\u3051\u3066\u4f55\u304b\u3092\u3059\u308b\u306e\u3067\u3059\u3002<\/p>\n<p>\u4f8b\u3048\u3070\u3001<span>&#8220;ABCD&#8221;<\/span>\u3068\u3044\u3046<span>String<\/span>\u306f\u3001<span>&#8216;A&#8217;<\/span>\u3001<span>&#8216;B&#8217;<\/span>\u3001<span>&#8216;C&#8217;<\/span>\u3001<span>&#8216;D&#8217;<\/span>\u3068\u3044\u3046\u56db\u3064\u306e<span>char<\/span>\u304c\u96c6\u307e\u3063\u3066\u9806\u756a\u306b\u4e26\u3093\u3060\u3082\u306e\u3067\u3059\u3002<span>Java<\/span>\u3067\u30c7\u30fc\u30bf\u306e\u96c6\u307e\u308a\u3092\u6271\u3046\u6642\u306f\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u3092\u4f7f\u3063\u3066\u30a2\u30af\u30bb\u30b9\u3059\u308b\u914d\u5217\u3092\u3088\u304f\u4f7f\u3044\u307e\u3059\u304c\u3001<span>String<\/span>\u306b\u3082\u540c\u3058\u3088\u3046\u306a\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u306e\u8003\u3048\u65b9\u304c\u3042\u308a\u307e\u3059\u306e\u3067\u3001\u914d\u5217\u306b\u4f3c\u3066\u3044\u308b\u3068\u306f\u8a00\u3048\u307e\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">char[] charArr = { 'A', 'B', 'C', 'D' };\r\nString str = \"ABCD\";<\/pre>\n<p>\u3067\u3082\u3001<span>String<\/span>\u3068<span>char<\/span>\u306e\u914d\u5217\u306f\u307e\u3063\u305f\u304f\u9055\u3046\u3082\u306e\u3067\u3059\u3002\u524d\u8ff0\u306e\u3068\u304a\u308a<span>String<\/span>\u306f\u30af\u30e9\u30b9\u306a\u306e\u3067\u3001\u6587\u5b57\u5217\u3092\u6271\u3046\u305f\u3081\u306e\u4fbf\u5229\u306a\u30e1\u30bd\u30c3\u30c9\u304c\u305f\u304f\u3055\u3093\u5099\u308f\u3063\u3066\u3044\u307e\u3059\u3002\u30c7\u30fc\u30bf\u306e\u5165\u308c\u7269\u3067\u3057\u304b\u306a\u3044\u914d\u5217\u3084\u3001\u30c7\u30fc\u30bf\u305d\u306e\u3082\u306e\u306e\u30d7\u30ea\u30df\u30c6\u30a3\u30d6\u578b\u3088\u308a\u3001<span>String<\/span>\u306f\u305a\u3063\u3068\u4f7f\u3044\u3084\u3059\u3044\u3082\u306e\u3067\u3059\u3002\u305d\u308c\u3089\u306e\u30e1\u30bd\u30c3\u30c9\u306e\u4f7f\u3044\u65b9\u306f\u5f8c\u8ff0\u3057\u307e\u3059\u3002<\/p>\n<h3><span id=\"-String82208221\">\uff11-\uff13\uff0eString\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u4f5c\u308b\u306b\u306f\u3001\u6587\u5b57\u5217\u3092<span>&#8220;&#8221;<\/span>\u3067\u56f2\u3046<\/span><\/h3>\n<p>Java\u3067<span>String<\/span>\u3092\u4f5c\u308b\u306b\u306f<span>&#8220;&#8221;(<\/span>\u30c0\u30d6\u30eb\u30af\u30a9\u30fc\u30c6\u30fc\u30b7\u30e7\u30f3<span>)<\/span>\u3067\u6587\u5b57\u30fb\u6587\u5b57\u5217\u3092\u304f\u304f\u308a\u307e\u3059\u3002\u305d\u308c\u3060\u3051\u3067\u3001<span>new<\/span>\u3057\u306a\u304f\u3066\u3082<span>String<\/span>\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u4f5c\u3063\u305f\u3053\u3068\u306b\u306a\u308b\u306e\u3067\u3059\u3002<\/p>\n<p>\u3067\u3059\u304b\u3089\u3001\u3042\u3068\u306f<span>String<\/span>\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u6307\u3059\u5909\u6570\u3092\u5ba3\u8a00\u3057\u3066\u53c2\u7167\u3055\u305b\u308c\u3070\u3001\u3082\u3046\u3042\u3068\u306f<span>String<\/span>\u3092\u3069\u3093\u3069\u3093\u4f7f\u3046\u3060\u3051\u3067\u3059\u3002\u3053\u306e\u3088\u3046\u306b\u3001<span>Java<\/span>\u3067\u306f<span>String<\/span>\u306f\u304b\u306a\u308a\u7279\u5225\u6271\u3044\u3055\u308c\u308b\u3082\u306e\u306a\u306e\u3067\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">String str = \"ABCD\";\r\nString str2 = \"\u3042\u3044\u3046\u3048\u304a\";<\/pre>\n<p>\u3061\u306a\u307f\u306b\u3001<span>&#8220;&#8221;<\/span>\u3067\u304f\u304f\u3063\u3066\u8868\u73fe\u3057\u305f\u6587\u5b57\u5217\u306f\u3001\u6587\u5b57\u5217\u30ea\u30c6\u30e9\u30eb<span>(string literal)<\/span>\u3068\u3082\u547c\u3070\u308c\u307e\u3059\u3002\u6587\u5b57\u5217\u305d\u306e\u3082\u306e\u3001\u3068\u3044\u3046\u610f\u5473\u3067\u3059\u3002<\/p>\n<p>\u305d\u3057\u3066\u3001<span>&#8220;&#8221;<\/span>\u3067\u304f\u304f\u3063\u305f\u6587\u5b57\u5217\u306f\u305d\u308c\u81ea\u4f53\u304c<span>String<\/span>\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u306a\u306e\u3067\u3001<span>String<\/span>\u304c\u6301\u3064\u30e1\u30bd\u30c3\u30c9\u3092\u3061\u3083\u3093\u3068\u547c\u3073\u51fa\u305b\u307e\u3059\u3002\u9762\u767d\u3044\u3067\u3059\u306d\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">System.out.println(\"\u3042\u3044\u3046\u3048\u304a\".length()); \/\/ \u2192 \u9577\u3055\u306f5<\/pre>\n<h4>\uff11-\uff13-\uff11\uff0eJava\u306e\u6587\u5b57\u5217\u30ea\u30c6\u30e9\u30eb\u3067\u7279\u5225\u306a\u610f\u5473\u3092\u6301\u3064\u6587\u5b57<\/h4>\n<p>\u6587\u5b57\u5217\u30ea\u30c6\u30e9\u30eb\u306f\u59cb\u3081\u3068\u7d42\u308f\u308a\u306b<span>&#8220;&#8221;<\/span>\u3092\u4f7f\u3044\u307e\u3059\u306e\u3067\u3001\u3053\u306e\u4e2d\u306b<span>&#8220;<\/span>\u305d\u306e\u3082\u306e\u3092\u542b\u3081\u305f\u3044\u5834\u5408\u306f\u3001<span>\\<\/span>\u3092\u305d\u306e\u524d\u306b\u7f6e\u304d\u307e\u3059\u3002\u3053\u308c\u3092\u30a8\u30b9\u30b1\u30fc\u30d7\u3068\u547c\u3073\u307e\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">String str = \"String\u306b\\\"\u3092\u542b\u3081\u3066\u307f\u308b\"; \/\/ \u2192 String\u306b\"\u3092\u542b\u3081\u3066\u307f\u308b<\/pre>\n<p>\u305d\u306e\u4ed6\u306b\u3082\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306a<span>char<\/span>\u3067\u3082\u4f7f\u3048\u308b\u7279\u6b8a\u306a\u6587\u5b57\u306e\u6307\u5b9a\u306f\u3001\u6587\u5b57\u5217\u30ea\u30c6\u30e9\u30eb\u306e\u4e2d\u3067\u3082\u6709\u52b9\u3067\u3059\u3002\u6587\u5b57\u3092\u30b3\u30fc\u30c9\u30dd\u30a4\u30f3\u30c8\u3067\u76f4\u63a5\u6307\u5b9a\u3059\u308b<span>\\uxxxx<\/span>\u3082\u4f7f\u3048\u307e\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">String str = \"\u30bf\u30d6=\\t\u3001\u6539\u884c=\\n\u3001\u5fa9\u5e30=\\r\u3001\u6539\u9801=\\f\u3001\u5186\u6587\u5b57(\u30d0\u30c3\u30af\u30b9\u30e9\u30c3\u30b7\u30e5)=\\\\\u3001\u30d0\u30c3\u30af\u30b9\u30da\u30fc\u30b9=\\b\u3001\u3042=\\u3042\";<\/pre>\n<h4>\uff11-\uff13-\uff12\uff0eJava\u306e\u6587\u5b57\u5217\u30ea\u30c6\u30e9\u30eb\u306f<span>&#8220;&#8221;<\/span>\u3060\u3051\u3092\u4f7f\u3046<\/h4>\n<p>JavaScript\u306a\u3069\u4ed6\u306e\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u8a00\u8a9e\u3067\u306f<span>&#8221;(<\/span>\u30b7\u30f3\u30b0\u30eb\u30af\u30a9\u30fc\u30c6\u30fc\u30b7\u30e7\u30f3<span>)<\/span>\u3067\u304f\u304f\u3063\u3066\u3082\u6587\u5b57\u5217\u3092\u4f5c\u308c\u307e\u3059\u3002\u3067\u3059\u304c\u3001<span>Java<\/span>\u3067\u306f<span>&#8221;<\/span>\u306f<span>char<\/span>\u306e\u4e00\u6587\u5b57\u3092\u8868\u3059\u3053\u3068\u306b\u4f7f\u308f\u308c\u307e\u3059\u306e\u3067\u3001\u4ee5\u4e0b\u306e\u30d7\u30ed\u30b0\u30e9\u30e0\u306f\u30b3\u30f3\u30d1\u30a4\u30eb\u30a8\u30e9\u30fc\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">\/\/ \u30b3\u30f3\u30d1\u30a4\u30eb\u30a8\u30e9\u30fc\u3001''\u306f\u4e00\u3064\u306e\u6587\u5b57(char)\u3092\u8868\u73fe\u3059\u308b\u306e\u306b\u4f7f\u3046\u3082\u306e\r\nString str = 'ABCD';\r\nString str2 = '\u3042\u3044\u3046\u3048\u304a';<\/pre>\n<h4>\uff11-\uff13-\uff13\uff0eString\u306e\u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf\u306f\u308f\u304b\u3063\u3066\u3044\u308b\u4eba\u5411\u3051<\/h4>\n<p>String\u306f\u30af\u30e9\u30b9\u3067\u3059\u3057\u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf\u3082\u3042\u308a\u307e\u3059\u304b\u3089\u3001<span>new<\/span>\u6f14\u7b97\u5b50\u3067<span>String<\/span>\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u4f5c\u308b\u3053\u3068\u3082\u3082\u3061\u308d\u3093\u3067\u304d\u307e\u3059\u3002\u3067\u3082\u3001<span>String<\/span>\u306e\u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf\u306b\u306f\u3001\u3044\u308f\u3086\u308b\u300c\u6587\u5b57\u30b3\u30fc\u30c9\u300d\u306e\u77e5\u8b58\u304c\u5fc5\u8981\u306a\u3082\u306e\u304c\u591a\u3044\u306e\u3067\u3001\u3042\u3089\u304b\u3058\u3081\u52c9\u5f37\u3057\u3066\u304b\u3089\u306e\u65b9\u304c\u3044\u3044\u3067\u3057\u3087\u3046\u3002\u7c21\u5358\u306a\u4f7f\u3044\u65b9\u306f\u5f8c\u8ff0\u3057\u307e\u3059\u3002<\/p>\n<p>\u3061\u306a\u307f\u306b\u3001<span>Java<\/span>\u306e\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u3067\u306f\u3001\u81ea\u5206\u3067<span>String<\/span>\u3092<span>new<\/span>\u3059\u308b\u6a5f\u4f1a\u306f\u3042\u307e\u308a\u306a\u304b\u3063\u305f\u308a\u3057\u307e\u3059\u3002\u5927\u62b5\u306f\u3001\u30e1\u30bd\u30c3\u30c9\u306e\u5f15\u6570\u3084\u623b\u308a\u5024\u306e<span>String<\/span>\u3092\u305d\u306e\u307e\u307e\u4f7f\u3046\u304b\u3089\u3067\u3059\u3002\u5384\u4ecb\u306a\u6587\u5b57\u30b3\u30fc\u30c9\u3082\u3001\u30d5\u30ec\u30fc\u30e0\u30ef\u30fc\u30af\u3067\u610f\u8b58\u3057\u306a\u304f\u3066\u3082\u3044\u3044\u3088\u3046\u306b\u3057\u3066\u304f\u308c\u3066\u3044\u308b\u3053\u3068\u3082\u591a\u3044\u306e\u3067\u3001\u5b66\u3076\u306e\u306f\u5fc5\u8981\u306b\u306a\u3063\u3066\u304b\u3089\u3067\u3082\u3044\u3044\u3067\u3057\u3087\u3046\u3002<\/p>\n<h3><span id=\"-String\">\uff11-\uff14\uff0eString\u3068\u30a4\u30f3\u30c7\u30c3\u30af\u30b9<\/span><\/h3>\n<p>\u3055\u304d\u307b\u3069\u3001<span>String<\/span>\u3068<span>char<\/span>\u306e\u914d\u5217\u306f\u9055\u3046\u3082\u306e\u3060\u3068\u66f8\u304d\u307e\u3057\u305f\u3002\u305d\u308c\u306f\u305d\u306e\u901a\u308a\u306a\u306e\u3067\u3059\u304c\u3001<span>String<\/span>\u3092\u6271\u3046\u4e0a\u3067\u306f\u914d\u5217\u3068\u540c\u69d8\u306b\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u306e\u8003\u3048\u65b9\u3092\u77e5\u3063\u3066\u304a\u304b\u306a\u3044\u3068\u3001<span>String<\/span>\u306e\u30e1\u30bd\u30c3\u30c9\u3092\u4f7f\u3046\u6642\u306b\u56f0\u3063\u305f\u3053\u3068\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n<p>\u3068\u3044\u3063\u3066\u3082\u3001<span>String<\/span>\u306e\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u306f\u96e3\u3057\u3044\u3082\u306e\u3067\u306f\u5168\u7136\u306a\u304f\u3001\u8981\u306f\u914d\u5217\u306e\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u3068\u540c\u3058\u3067\u3059\u3002<span>String<\/span>\u304c\u6301\u3063\u3066\u3044\u308b\u6587\u5b57\u5217\u306e\u6587\u5b57\u4e00\u3064\u4e00\u3064\u306b\u30a2\u30af\u30bb\u30b9\u3057\u305f\u308a\u3001\u7bc4\u56f2\u3092\u6307\u5b9a\u3059\u308b\u306b\u306f\u3001\u914d\u5217\u3068\u540c\u3058\u3088\u3046\u306b\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u3068\u3044\u3046\u4f4d\u7f6e\u3067\u6307\u5b9a\u3059\u308b<span>\u2026<\/span>\u3068\u3044\u3046\u3060\u3051\u306a\u306e\u3067\u3059\u3002<\/p>\n<p>String\u3068\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u306e\u8003\u3048\u65b9\u306f\u3001\u4ee5\u4e0b\u306e\u56f3\u306e\u3068\u304a\u308a\u306b\u306a\u308a\u307e\u3059\u3002\u914d\u5217\u3068\u540c\u3058\u3067\u3059\u306d\u3002<span>Excel<\/span>\u306e\u95a2\u6570\u3084<span>SQL<\/span>\u3001\u4ed6\u306e\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u8a00\u8a9e\u3068\u3082\u540c\u3058\u3060\u3068\u8a00\u3048\u307e\u3059\u3002\u305f\u3060\u3001<span>Java<\/span>\u306e<span>String<\/span>\u3067\u306f\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u306f<span>0<\/span>\u59cb\u307e\u308a\u3060\u3068\u3044\u3046\u3053\u3068\u306f\u3001\u7d76\u5bfe\u306b\u899a\u3048\u3066\u304a\u304d\u307e\u3057\u3087\u3046\u3002<\/p>\n<p><a href=\"https:\/\/www.bold.ne.jp\/engineer-club\/wp-content\/uploads\/2019\/02\/9e6d179c2bfec5f2e31c9f52be3a4920.png\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/www.bold.ne.jp\/engineer-club\/wp-content\/uploads\/2019\/02\/9e6d179c2bfec5f2e31c9f52be3a4920.png\" alt=\"String\u306e\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u306e\u8003\u3048\u65b9\" width=\"960\" height=\"720\" class=\"alignnone size-full wp-image-1369\" srcset=\"https:\/\/www.bold.ne.jp\/engineer-club\/wp-content\/uploads\/2019\/02\/9e6d179c2bfec5f2e31c9f52be3a4920.png 960w, https:\/\/www.bold.ne.jp\/engineer-club\/wp-content\/uploads\/2019\/02\/9e6d179c2bfec5f2e31c9f52be3a4920-768x576.png 768w\" sizes=\"(max-width: 960px) 100vw, 960px\" \/><\/a><\/p>\n<h3><span id=\"-8220string8221\">\uff11-\uff15\uff0e\u3010\u53c2\u8003\u3011\u306a\u305c<span>&#8220;string&#8221;<\/span>\u3068\u547c\u3070\u308c\u308b\u306e\u304b<span>?<\/span><\/span><\/h3>\n<p>\u306a\u305c\u3053\u308c\u3089\u306e\u6587\u5b57\u306e\u96c6\u307e\u308a\u3092<span>string<\/span>\u3068\u547c\u3076\u306e\u3067\u3057\u3087\u3046\u304b\u3002\u305d\u308c\u306f\u3001<span>string<\/span>\u3068\u3044\u3046\u5358\u8a9e\u306b\u306f\u300c\u3072\u3082\u300d\u3084\u300c\u7cf8\u300d\u306e\u4ed6\u306b\u3082\u3001\u300c\u3072\u3082\u306b\u901a\u3057\u305f\u3082\u306e\u3001\u6570\u73e0\u3064\u306a\u304e\u306b\u306a\u3063\u305f\u3082\u306e\u3001\u4e00\u9023\u3001\u3072\u3068\u7d9a\u304d\u300d<span>(weblib<\/span>\u82f1\u548c\u8f9e\u5178<span>)<\/span>\u3068\u3044\u3046\u610f\u5473\u304c\u3042\u308b\u304b\u3089\u3067\u3059\u3002\u3064\u307e\u308a\u3001\u6587\u5b57\u5217\u3068\u306f<span>string of characters<\/span>\u3067\u3042\u308b\u3001\u3068\u3044\u3046\u308f\u3051\u3067\u3059\u3002<\/p>\n<p>\u6587\u5b57\u304c\u4e00\u5217\u306b\u306a\u3063\u3066\u3044\u308b\u69d8\u5b50\u304c\u3001<span>string<\/span>\u3092\u6587\u5b57\u5217\u306e\u610f\u5473\u3067\u4f7f\u3044\u59cb\u3081\u305f\u4eba\u306b\u306f\u3074\u3063\u305f\u308a\u3060\u3068\u601d\u3048\u305f\u306e\u3067\u3057\u3087\u3046\u3002\u305d\u3057\u3066\u3001\u4eca\u306e\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u8a00\u8a9e\u3067\u306e\u610f\u5473\u3067\u306e<span>string<\/span>\u306e\u7528\u6cd5\u306f\u3001\u3069\u3046\u3084\u3089<span>1950<\/span>\uff5e<span>60<\/span>\u5e74\u4ee3\u306b\u306f\u65e2\u306b\u3042\u3063\u305f\u3088\u3046\u3067\u3059\u306d\u3002<\/p>\n<h2><span id=\"String\">\uff12\uff0e\u3010\u57fa\u672c\u3011<span>String<\/span>\u3092\u4f7f\u3063\u3066\u307f\u308b<\/span><\/h2>\n<p>\u3067\u306f\u3001\u3055\u3063\u305d\u304f<span>String<\/span>\u3092\u3069\u3093\u3069\u3093\u4f7f\u3063\u3066\u307f\u3066\u3001<span>String<\/span>\u304c\u3069\u3046\u3044\u3046\u3082\u306e\u304b\u3092\u4f53\u9a13\u3057\u3066\u3044\u304d\u307e\u3057\u3087\u3046<span>!<\/span><\/p>\n<p>\u3053\u306e\u7ae0\u3067\u306f\u3001<span>Java 7<\/span>\u307e\u3067\u306e<span>String<\/span>\u306b\u3042\u308b\u30e1\u30bd\u30c3\u30c9\u3092\u3001\u4f7f\u3044\u65b9\u3068\u4e00\u7dd2\u306b\u7c21\u5358\u306b\u7d39\u4ecb\u3057\u307e\u3059\u3002\u30d7\u30ed\u30b0\u30e9\u30e0\u3092\u4f5c\u308b\u73fe\u5834\u3067\u306f<span>Java 7<\/span>\u4ee5\u524d\u304c\u4f7f\u308f\u308c\u3066\u3044\u308b\u3053\u3068\u304c\u307e\u3060\u307e\u3060\u591a\u3044\u306e\u3067\u3001\u3053\u306e\u7ae0\u3067<span>String<\/span>\u306e\u57fa\u672c\u3092\u5b66\u3079\u3070\u3001\u3069\u3093\u306a\u5834\u6240\u3067\u3082<span>String<\/span>\u3092\u4f7f\u3044\u3053\u306a\u3059\u305f\u3081\u306e\u57fa\u790e\u77e5\u8b58\u304c\u8eab\u306b\u7740\u304d\u307e\u3059\u3088\u3002<\/p>\n<p>\u306a\u304a\u3001<span>Java 8<\/span>\u4ee5\u964d\u306e<span>String<\/span>\u306e\u5909\u66f4\u70b9\u3082\u3053\u306e\u7ae0\u306e\u4e2d\u3067\u306f\u8efd\u304f\u89e6\u308c\u307e\u3059\u304c\u3001\u8a73\u7d30\u3092\u8a18\u8ff0\u3057\u305f\u5225\u306e\u7ae0\u3092\u7528\u610f\u3057\u307e\u3057\u305f\u306e\u3067\u3001\u305d\u3061\u3089\u3082\u8aad\u3093\u3067\u307f\u3066\u304f\u3060\u3055\u3044\u3002<\/p>\n<h3><span id=\"-length\">\uff12-\uff11\uff0e\u6587\u5b57\u306e\u6570\u3092\u8abf\u3079\u308b<span>length<\/span><\/span><\/h3>\n<p>String.length\u3092\u4f7f\u3046\u3068\u3001<span>String<\/span>\u304c\u6301\u3063\u3066\u3044\u308b\u6587\u5b57\u306e\u6570<span>(=<\/span>\u6587\u5b57\u5217\u306e\u9577\u3055<span>)<\/span>\u304c\u308f\u304b\u308a\u307e\u3059\u3002<span>length<\/span>\u306f\u3001\u914d\u5217\u3067\u306f<span>int<\/span>\u306e\u5024\u3067\u3059\u304c\u3001<span>String<\/span>\u3067\u306f<span>int<\/span>\u3092\u623b\u3059\u30e1\u30bd\u30c3\u30c9\u3067\u3059\u3002\u623b\u3063\u3066\u304f\u308b\u6570\u5024\u306f\u3001\u3044\u308f\u3086\u308b\u5168\u89d2\u534a\u89d2\u304c\u95a2\u4fc2\u3059\u308b\u30d0\u30a4\u30c8\u6570\u3067\u306f\u306a\u304f\u3001\u3042\u304f\u307e\u3067\u6587\u5b57\u6570\u3067\u3059\u3002\u308f\u304b\u308a\u3084\u3059\u3044\u3067\u3059\u306d\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">String str = \"String\";\r\nString str2 = \"\u3042\u3044\u3046\u3048\u304a\";\r\nint length = str.length();\r\nint length2 = str2.length();\r\nSystem.out.println(length); \/\/ \u2192 6\r\nSystem.out.println(length2); \/\/ \u2192 5(Shift_JIS\u306e10\u30d0\u30a4\u30c8\u3067\u3082\u3001UTF-8\u306e15\u30d0\u30a4\u30c8\u3067\u3082\u306a\u3044)<\/pre>\n<p>\u305d\u3057\u3066\u3001\u30d7\u30ed\u30b0\u30e9\u30e0\u3092\u4f5c\u3063\u3066\u3044\u308b\u3068\u3001<span>String<\/span>\u304c\u4f55\u6587\u5b57\u304b\u3067\u306f\u306a\u304f\u4f55\u30d0\u30a4\u30c8\u304b\u77e5\u308a\u305f\u3044\u3053\u3068\u304c\u3042\u308a\u307e\u3059\u3002\u305d\u306e\u65b9\u6cd5\u306f\u5f8c\u8ff0\u3057\u307e\u3059\u3002<\/p>\n<h4>\uff12-\uff11-\uff11\uff0eString\u304c\u7a7a\u304b\u3069\u3046\u304b\u8abf\u3079\u308b<span>isEmpty<\/span><\/h4>\n<p>String\u304c\u7a7a\u304b<span>(=<\/span>\u6587\u5b57\u6570\u304c<span>0)<\/span>\u3069\u3046\u304b\u306e\u78ba\u8a8d\u306b\u306f\u3001<span>boolean<\/span>\u3092\u623b\u3059<span>String.isEmpty<\/span>\u3092\u4f7f\u3044\u307e\u3057\u3087\u3046<span>(Java 6<\/span>\u4ee5\u964d<span>)<\/span>\u3002<span>length<\/span>\u306e\u7d50\u679c\u304c<span>0<\/span>\u304b<span>\u2026<\/span>\u3067\u3082\u3044\u3044\u306e\u3067\u3059\u304c\u3001<span>isEmpty<\/span>\u306a\u3089\u30d7\u30ed\u30b0\u30e9\u30e0\u304c<span>(<\/span>\u3061\u3087\u3063\u3068<span>)<\/span>\u77ed\u304f\u306a\u308a\u307e\u3059\u3057\u3001\u884c\u3063\u3066\u3044\u308b\u3053\u3068\u306e\u300c\u610f\u5473\u300d\u3082\u5206\u304b\u308a\u3084\u3059\u304f\u306a\u308a\u307e\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">String str = \"\";\r\n\r\nif (str.isEmpty()) {\r\n\tSystem.out.println(\"\u6587\u5b57\u5217\u306f\u7a7a\u3067\u3059\");\r\n}\r\n\r\nif (str.length() == 0) {\r\n\tSystem.out.println(\"\u6587\u5b57\u5217\u306f\u7a7a\u3067\u3059\");\r\n}<\/pre>\n<p>\u3061\u306a\u307f\u306b\u3001<span>Java 11<\/span>\u3067\u306f<span>String.isBlank<\/span>\u3068\u3044\u3046\u3001\u6587\u5b57\u5217\u304c\u5168\u90e8\u7a7a\u767d\u6271\u3044\u3067\u304d\u308b\u6587\u5b57\u304b\u3092\u78ba\u8a8d\u3059\u308b\u30e1\u30bd\u30c3\u30c9\u304c\u8ffd\u52a0\u3055\u308c\u307e\u3057\u305f\u3002<span>isBlank<\/span>\u306b\u3064\u3044\u3066\u306f\u5f8c\u8ff0\u3057\u307e\u3059\u3002<\/p>\n<h3><span id=\"-substring\">\uff12-\uff12\uff0e\u90e8\u5206\u6587\u5b57\u5217\u3092\u5207\u308a\u51fa\u3059<span>substring<\/span><\/span><\/h3>\n<p>String\u304b\u3089\u3001\u3042\u308b\u4f4d\u7f6e\u304b\u3089\u3042\u308b\u6587\u5b57\u6570\u306e\u6587\u5b57\u5217\u3092\u5207\u308a\u51fa\u3059\u6642\u306b\u306f\u3001<span>String.substring<\/span>\u3092\u4f7f\u3044\u307e\u3059\u3002<\/p>\n<p>substring\u306e\u623b\u308a\u5024\u306f\u3001\u6307\u5b9a\u3057\u305f\u958b\u59cb\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u304b\u3089\u7d42\u4e86\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u306e\u524d\u307e\u3067\u306b\u3042\u308b\u6587\u5b57\u5217\u306e\u3001\u65b0\u3057\u3044<span>String<\/span>\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3067\u3059\u3002\u6307\u5b9a\u3059\u308b\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u306f\u3001<span>String<\/span>\u3092<span>char<\/span>\u306e\u914d\u5217\u3068\u3057\u3066\u8003\u3048\u305f\u6642\u306e\u3001\u914d\u5217\u306e\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u306e\u6570\u5024\u3067\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">String str = \"\u3042\u3044\u3046\u3048\u304a\"; \/\/ [0:'\u3042', 1:'\u3044', 2:'\u3046', 3:'\u3048', 4:'\u304a']\r\nString str2 = str.substring(1, 3); \/\/ \u30a4\u30f3\u30c7\u30c3\u30af\u30b91\u304b\u3089\u30013\u306e\u524d\u307e\u3067\r\nString str3 = str.substring(0, 2); \/\/ \u30a4\u30f3\u30c7\u30c3\u30af\u30b90\u304b\u3089\u30012\u306e\u524d\u307e\u3067\r\nString str4 = str.substring(3); \/\/ \u30a4\u30f3\u30c7\u30c3\u30af\u30b93\u304b\u3089\u3001\u6700\u5f8c\u307e\u3067\r\nSystem.out.println(str2); \/\/ \u2192 \u3044\u3046\r\nSystem.out.println(str3); \/\/ \u2192 \u3042\u3044\r\nSystem.out.println(str4); \/\/ \u2192 \u3048\u304a<\/pre>\n<p>String.substring\u306b\u3064\u3044\u3066\u306f\u3001\u4ee5\u4e0b\u306e\u8a18\u4e8b\u3082\u53c2\u7167\u3057\u3066\u304f\u3060\u3055\u3044\u3002<\/p>\n\n<span style=\"text-decoration:none !important; background-color:#a61e58; color:white; padding:4px 13px; font-size:12px; font-weight:bold; position:relative; top:10px; z-index:1; left:11px;\">\u95a2\u9023\u8a18\u4e8b<\/span>\n<div class=\"blog-card\"><a target=\"_blank\" href=\"https:\/\/www.bold.ne.jp\/engineer-club\/java-substring\" style=\"text-decoration:none;\">\n    <div class=\"blog-card-thumbnail\"><img src='https:\/\/www.bold.ne.jp\/engineer-club\/wp-content\/uploads\/2018\/10\/shutterstock_568617811-600x366.jpg' alt='Java\u306esubstring\u3068\u306f\uff1f\u90e8\u5206\u6587\u5b57\u5217\u53d6\u5f97\u306e\u57fa\u672c\u300cString.substring()\u300d\u306e\u4f7f\u3044\u65b9' width=160 height=98 \/><\/div>\n    <div class=\"blog-card-content\">\n        <div class=\"blog-card-title\">Java\u306esubstring\u3068\u306f\uff1f\u90e8\u5206\u6587\u5b57\u5217\u53d6\u5f97\u306e\u57fa\u672c\u300cString.substring()\u300d\u306e\u4f7f\u3044\u65b9 <\/div>\n        <span style=\"font-size: 12px; font-weight: normal; position:relative; color:#666;\"><i class=\"fa fa-clock-o\"><\/i>&nbsp;2025\/09\/17<\/span>\n    <\/div>\n<div class=\"clear\"><\/div>\n<\/a><\/div>\n<p>\u3061\u306a\u307f\u306b\u3001\u4f8b\u3048\u3070<span>Shift_JIS<\/span>\u3067\u8868\u3055\u308c\u308b\u6587\u5b57\u306e<span>2<\/span>\u30d0\u30a4\u30c8\u76ee\u304b\u3089\u5207\u308a\u51fa\u3057\u3066\u3057\u307e\u3063\u305f<span>\u2026<\/span>\u3068\u3044\u3046\u60b2\u3057\u3044\u4e8b\u4ef6\u306f\u3001<span>Java<\/span>\u3067\u306f\u8d77\u3053\u308a\u307e\u305b\u3093\u3002\u4f55\u5ea6\u3082\u304a\u4f1d\u3048\u3057\u3066\u3044\u308b\u3068\u304a\u308a\u3001<span>String<\/span>\u304c\u6271\u3046\u5358\u4f4d\u306f\u30d0\u30a4\u30c8\u3067\u306f\u306a\u304f\u3001\u6587\u5b57\u3060\u304b\u3089\u3067\u3059\u3002<\/p>\n<h4>\uff12-\uff12-\uff11\uff0e\u4e00\u6587\u5b57\u3060\u3051\u5207\u308a\u51fa\u3059<span>charAt<\/span><\/h4>\n<p>String\u304c\u6301\u3064\u6587\u5b57\u5217\u304b\u3089\u3001\u3042\u308b\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u306e\u6587\u5b57\u3060\u3051\u5207\u308a\u51fa\u3057\u305f\u3044\u306a\u3089\u3001<span>charAt<\/span>\u3082\u4f7f\u3048\u307e\u3059\u3002\u3053\u306e\u30e1\u30bd\u30c3\u30c9\u306f\u3001\u6307\u5b9a\u3055\u308c\u305f\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u306b\u3042\u308b\u6587\u5b57\u3092\u3001<span>char<\/span>\u3067\u53d6\u308a\u51fa\u3057\u307e\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">String str = \"\u3042\u3044\u3046\u3048\u304a\"; \/\/ [0:'\u3042', 1:'\u3044', 2:'\u3046', 3:'\u3048', 4:'\u304a']\r\nchar a = str.charAt(0);\r\nchar i = str.charAt(1);\r\nchar u = str.charAt(2);\r\nchar e = str.charAt(3);\r\nchar o = str.charAt(4);\r\nSystem.out.println(a);\r\nSystem.out.println(i);\r\nSystem.out.println(u);\r\nSystem.out.println(e);\r\nSystem.out.println(o);<\/pre>\n<p>\u306a\u304a\u3001\u6587\u5b57\u3092<span>int<\/span>\u3067\u53d6\u308a\u51fa\u3059<span>codePointAt<\/span>\u3068\u3044\u3046\u30e1\u30bd\u30c3\u30c9\u3082\u3042\u308a\u307e\u3059\u3002\u3067\u3082\u3001\u3053\u306e\u30e1\u30bd\u30c3\u30c9\u304c\u306a\u305c<span>charAt<\/span>\u3068\u306f\u5225\u306b\u3042\u308b\u306e\u304b\u3001\u3069\u3046\u3044\u3046\u6642\u306b\u4f7f\u3046\u304b\u306f\u3001\u6587\u5b57\u30b3\u30fc\u30c9<span>\u2026<\/span>\u7279\u306b<span>Unicode<\/span>\u306e\u30b5\u30ed\u30b2\u30fc\u30c8\u30da\u30a2\u3068\u3044\u3046\u3082\u306e\u306e\u77e5\u8b58\u304c\u5fc5\u8981\u306b\u306a\u308a\u307e\u3059\u306e\u3067\u3001\u3053\u3053\u3067\u306f\u89e6\u308c\u307e\u305b\u3093\u3002<\/p>\n<h3><span id=\"i\">\uff12-\uff13\uff0e\u6587\u5b57\u5217\u3092\u542b\u3080\u304b\u8abf\u3079\u308b<\/span><\/h3>\n<p>String\u304c\u6301\u3063\u3066\u3044\u308b\u6587\u5b57\u5217\u306b\u3001\u5225\u306e\u6587\u5b57\u5217\u3092\u542b\u3093\u3067\u3044\u308b\u304b\u78ba\u8a8d\u3057\u305f\u3044\u6642\u304c\u3042\u308a\u307e\u3059\u3002\u305d\u306e\u6642\u306b\u306f\u3001<span>String.contains\/indexOf\/matches<\/span>\u306a\u3069\u3092\u4f7f\u3044\u307e\u3059\u3002<\/p>\n<h4>\uff12-\uff13-\uff11\uff0e\u6587\u5b57\u5217\u3092\u542b\u3080\u304b\u8abf\u3079\u308b<span>contains\/startsWith\/endsWith<\/span><\/h4>\n<p>String\u304c\u6587\u5b57\u5217\u3092\u542b\u3093\u3067\u3044\u308b\u304b\u3060\u3051<span>boolean<\/span>\u3067\u77e5\u308a\u305f\u3051\u308c\u3070\u3001<span>String.contains<\/span>\u3092\u4f7f\u3044\u307e\u3057\u3087\u3046\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">String str = \"\u3042\u3044\u3046\u3044\u3042\"; \/\/ [0:'\u3042', 1:'\u3044', 2:'\u3046', 3:'\u3044', 4:'\u3042']\r\nboolean contains = str.contains(\"\u3046\");\r\nSystem.out.println(contains); \/\/ \u2192 true<\/pre>\n<p>String.contains\u3084\u3001\u305d\u306e\u4ed6\u306e\u300c\u542b\u3080\u300d\u306e\u8abf\u3079\u65b9\u306b\u3064\u3044\u3066\u306f\u3001\u4ee5\u4e0b\u306e\u8a18\u4e8b\u3082\u53c2\u7167\u3057\u3066\u304f\u3060\u3055\u3044\u3002<\/p>\n\n<span style=\"text-decoration:none !important; background-color:#a61e58; color:white; padding:4px 13px; font-size:12px; font-weight:bold; position:relative; top:10px; z-index:1; left:11px;\">\u95a2\u9023\u8a18\u4e8b<\/span>\n<div class=\"blog-card\"><a target=\"_blank\" href=\"https:\/\/www.bold.ne.jp\/engineer-club\/java-contains\" style=\"text-decoration:none;\">\n    <div class=\"blog-card-thumbnail\"><img src='https:\/\/www.bold.ne.jp\/engineer-club\/wp-content\/uploads\/2018\/10\/shutterstock_568617811-600x366.jpg' alt='Java\u306econtains\u3068\u306f\uff1fcontains\u3067\u300c\u542b\u3080\u300d\u3092\u30c1\u30a7\u30c3\u30af\u3059\u308b\u65b9\u6cd5' width=160 height=98 \/><\/div>\n    <div class=\"blog-card-content\">\n        <div class=\"blog-card-title\">Java\u306econtains\u3068\u306f\uff1fcontains\u3067\u300c\u542b\u3080\u300d\u3092\u30c1\u30a7\u30c3\u30af\u3059\u308b\u65b9\u6cd5 <\/div>\n        <span style=\"font-size: 12px; font-weight: normal; position:relative; color:#666;\"><i class=\"fa fa-clock-o\"><\/i>&nbsp;2025\/10\/06<\/span>\n    <\/div>\n<div class=\"clear\"><\/div>\n<\/a><\/div>\n<p>\u306a\u304a\u3001\u5148\u982d\u306b\u3042\u308b\u3053\u3068\u304c\u5206\u304b\u308c\u3070\u3044\u3044\u3060\u3051\u306a\u3089<span>String.startsWith<\/span>\u3001\u6700\u5f8c\u306b\u3042\u308b\u3053\u3068\u304c\u5206\u304b\u308c\u3070\u3044\u3044\u3060\u3051\u306a\u3089<span>String.endsWith<\/span>\u3082\u4fbf\u5229\u306b\u4f7f\u3048\u307e\u3059\u3088\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">String str = \"\u3042\u3044\u3046\u3048\u304a\";\r\nboolean start = str.startsWith(\"\u3042\u3044\u3046\");\r\nboolean end = str.endsWith(\"\u3046\u3048\u304a\");\r\nSystem.out.println(start); \/\/ \u2192 true\r\nSystem.out.println(end); \/\/ \u2192 true<\/pre>\n<h4>\uff12-\uff13-\uff12\uff0e\u6587\u5b57\u5217\u306e\u51fa\u73fe\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u3092\u8abf\u3079\u308b<span>indexOf<\/span><\/h4>\n<p>String\u306e\u4e2d\u3067\u3001\u6587\u5b57\u5217\u304c\u59cb\u307e\u308b\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u3092\u77e5\u308a\u305f\u3051\u308c\u3070\u3001<span>String.indexOf(<\/span>\u524d\u304b\u3089\u8abf\u3079\u308b<span>)\/lastIndexOf(<\/span>\u5f8c\u308d\u304b\u3089\u8abf\u3079\u308b<span>)<\/span>\u3092\u4f7f\u3044\u307e\u3057\u3087\u3046\u3002<span>indexOf\/lastIndexOf<\/span>\u306f\u3001\u524d\u8ff0\u3057\u305f<span>substring<\/span>\u3068\u7d44\u307f\u5408\u308f\u305b\u308b\u306e\u304c\u3088\u304f\u3042\u308b\u4f7f\u3044\u65b9\u3067\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">String str = \"\u3042\u3044\u3046\u3044\u3042\"; \/\/ [0:'\u3042', 1:'\u3044', 2:'\u3046', 3:'\u3044', 4:'\u3042']\r\nint index = str.indexOf(\"\u3044\");\r\nint lastIndex = str.lastIndexOf(\"\u3044\");\r\nSystem.out.println(index); \/\/ \u2192 1(\u524d\u304b\u3089\u8abf\u3079\u308b)\r\nSystem.out.println(lastIndex); \/\/ \u2192 3(\u5f8c\u308d\u304b\u3089\u8abf\u3079\u308b)<\/pre>\n\n<span style=\"text-decoration:none !important; background-color:#a61e58; color:white; padding:4px 13px; font-size:12px; font-weight:bold; position:relative; top:10px; z-index:1; left:11px;\">\u95a2\u9023\u8a18\u4e8b<\/span>\n<div class=\"blog-card\"><a target=\"_blank\" href=\"https:\/\/www.bold.ne.jp\/engineer-club\/java-indexof\" style=\"text-decoration:none;\">\n    <div class=\"blog-card-thumbnail\"><img src='https:\/\/www.bold.ne.jp\/engineer-club\/wp-content\/uploads\/2018\/10\/shutterstock_568617811-600x366.jpg' alt='Java\u306eindexof\u3068\u306f\uff1f\u6587\u5b57\u30fb\u6587\u5b57\u5217\u306e\u4f4d\u7f6e\u3092\u8abf\u3079\u308bString.indexOf\/lastIndexOf\u306e\u4f7f\u3044\u65b9' width=160 height=98 \/><\/div>\n    <div class=\"blog-card-content\">\n        <div class=\"blog-card-title\">Java\u306eindexof\u3068\u306f\uff1f\u6587\u5b57\u30fb\u6587\u5b57\u5217\u306e\u4f4d\u7f6e\u3092\u8abf\u3079\u308bString.indexOf\/lastIndexOf\u306e\u4f7f\u3044\u65b9 <\/div>\n        <span style=\"font-size: 12px; font-weight: normal; position:relative; color:#666;\"><i class=\"fa fa-clock-o\"><\/i>&nbsp;2025\/09\/17<\/span>\n    <\/div>\n<div class=\"clear\"><\/div>\n<\/a><\/div>\n<h4>\uff12-\uff13-\uff13\uff0e\u6587\u5b57\u5217\u3092\u30de\u30c3\u30c1\u30f3\u30b0\u3059\u308b<span>matches<\/span><\/h4>\n<p>contains\u3084<span>indexOf<\/span>\u3067\u306f\u3001\u4e00\u3064\u306e\u56fa\u5b9a\u3055\u308c\u305f\u6587\u5b57\u5217\u3057\u304b\u63a2\u305b\u307e\u305b\u3093\u3002\u3053\u308c\u3092\u6b63\u898f\u8868\u73fe\u3068\u547c\u3070\u308c\u308b\u30d1\u30bf\u30fc\u30f3\u3067\u6307\u5b9a\u3059\u308b\u306b\u306f\u3001<span>String.matches<\/span>\u3092\u4f7f\u3044\u307e\u3059\u3002<\/p>\n<p>\u4f8b\u3048\u3070\u3001\u6587\u5b57\u5217\u5168\u4f53\u304c\u7279\u5b9a\u306e\u30d1\u30bf\u30fc\u30f3\u3067\u3042\u308b\u304b\u8abf\u3079\u305f\u3044\u306a\u3089\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u3059\u308c\u3070\u3067\u304d\u307e\u3059\u3002<span>&#8220;|&#8221;<\/span>\u306f\u3001\u307e\u305f\u306f\uff5e\u3068\u3044\u3046\u610f\u5473\u3067\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">String str1 = \"\u732b\u306f\u304b\u308f\u3044\u3044\";\r\nString str2 = \"\u732b\u306f\u304b\u308f\u3044\u304f\u306a\u3044\";\r\nboolean match1 = str1.matches(\"\u732b\u306f(\u304b\u308f\u3044\u3044|\u3059\u3070\u3089\u3057\u3044)\");\r\nboolean match2 = str2.matches(\"\u732b\u306f(\u304b\u308f\u3044\u3044|\u3059\u3070\u3089\u3057\u3044)\");\r\nSystem.out.println(match1); \/\/ \u2192 true\r\nSystem.out.println(match2); \/\/ \u2192 false<\/pre>\n<p>\u6587\u5b57\u5217\u306e\u4e00\u90e8\u5206\u3060\u3051\u542b\u3081\u3070\u3044\u3044\u306a\u3089\u3001\u5c11\u3057\u66f8\u304d\u65b9\u3092\u5909\u3048\u307e\u3059\u3002\u30de\u30c3\u30c1\u3055\u305b\u305f\u3044\u3068\u3053\u308d\u306e\u524d\u5f8c\u306b<span>&#8220;.*&#8221;(=<\/span>\u3069\u3093\u306a\u6587\u5b57\u3067\u3082<span>0<\/span>\u6587\u5b57\u4ee5\u4e0a\u542b\u3080<span>)<\/span>\u3092\u4ed8\u3051\u3066\u3044\u308b\u306e\u304c\u30dd\u30a4\u30f3\u30c8\u3067\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">String str1 = \"\u732b\u306f\u3059\u3054\u304f\u304b\u308f\u3044\u3044\u3001\u3059\u3066\u304d\u306a\u52d5\u7269\u3067\u3059\";\r\nString str2 = \"\u72ac\u306f\u4eba\u985e\u306e\u53cb\u3067\u3042\u308b\u3059\u3070\u3089\u3057\u3044\u30d1\u30fc\u30c8\u30ca\u30fc\u3067\u3059\";\r\nboolean match1 = str1.matches(\".*(\u304b\u308f\u3044\u3044|\u3059\u3070\u3089\u3057\u3044).*\");\r\nboolean match2 = str2.matches(\".*(\u304b\u308f\u3044\u3044|\u3059\u3070\u3089\u3057\u3044).*\");\r\nSystem.out.println(match1); \/\/ \u2192 true\r\nSystem.out.println(match2); \/\/ \u2192 true<\/pre>\n<p>\u6b63\u898f\u8868\u73fe\u3092\u4f7f\u3044\u3053\u306a\u3059\u3068\u3001\u5927\u5909\u4fbf\u5229\u306b<span>String<\/span>\u3068\u306e\u30de\u30c3\u30c1\u30f3\u30b0\u304c\u884c\u3048\u307e\u3059\u3002\u8208\u5473\u304c\u3042\u308c\u3070\u305c\u3072\u8abf\u3079\u3066\u307f\u3066\u3001\u4f7f\u3044\u3053\u306a\u305b\u308b\u3088\u3046\u306b\u306a\u308a\u307e\u3057\u3087\u3046<span>!!<\/span><\/p>\n<h3><span id=\"i-2\">\uff12-\uff14\uff0e\u6587\u5b57\u5217\u3092\u5909\u63db\u3059\u308b<\/span><\/h3>\n<h4>\uff12-\uff14-\uff11\uff0e\u6587\u5b57\u5217\u306e\u4e00\u90e8<span>\/<\/span>\u5168\u90e8\u3092\u7f6e\u63db\u3059\u308b<span>replace\/replaceAll<\/span><\/h4>\n<p>String\u304c\u6301\u3064\u6587\u5b57\u5217\u306e\u4e00\u90e8\u3001\u3042\u308b\u3044\u306f\u3059\u3079\u3066\u3092\u7f6e\u63db\u3059\u308b\u306b\u306f\u3001<span>String.replace\/replaceAll<\/span>\u3092\u4f7f\u3044\u307e\u3059\u3002<\/p>\n<p>replace\u306f\u5dee\u3057\u66ff\u3048\u308b\u6587\u5b57\u5217\u304c\u6700\u521d\u306b\u51fa\u305f\u90e8\u5206\u306e\u307f\u7f6e\u63db\u3057\u305f\u3001<span>replaceAll<\/span>\u306f\u51fa\u73fe\u3059\u308b\u90e8\u5206\u3059\u3079\u3066\u3092\u7f6e\u63db\u3057\u305f\u3001<span>String<\/span>\u306e\u65b0\u3057\u3044\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u623b\u3057\u307e\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">String str = \"\u3042\u3044\u3046\u3048\u304a\u3042\u3044\u3046\u3048\u304a\";\r\nString replaced = str.replace(\"\u3042\", \"A\");\r\nSystem.out.println(replaced); \/\/ \u2192 A\u3044\u3046\u3048\u304a\u3042\u3044\u3046\u3048\u304a<\/pre>\n<pre class=\"prettyprint lang:default decode:true\">String str = \"\u3042\u3044\u3046\u3048\u304a\u3042\u3044\u3046\u3048\u304a\";\r\nString replaced = str.replaceAll(\"\u3042\", \"A\");\r\nSystem.out.println(replaced); \/\/ \u2192 A\u3044\u3046\u3048\u304aA\u3044\u3046\u3048\u304a<\/pre>\n<p>replaceAll\u306e\u4e00\u756a\u76ee\u306e\u5f15\u6570\u3082\u3001<span>split<\/span>\u3068\u540c\u69d8\u306b\u6b63\u898f\u8868\u73fe\u3092\u6307\u5b9a\u3067\u304d\u307e\u3059\u3002\u3067\u3059\u304b\u3089\u3001\u7f6e\u63db\u6761\u4ef6\u3092\u304b\u306a\u308a\u67d4\u8edf\u306b\u8a2d\u5b9a\u3067\u304d\u305f\u308a\u3057\u307e\u3059\u3002<\/p>\n<p>String.replace\/replaceAll\u306b\u3064\u3044\u3066\u306f\u3001\u4ee5\u4e0b\u306e\u8a18\u4e8b\u3082\u53c2\u7167\u3057\u3066\u304f\u3060\u3055\u3044\u3002<\/p>\n\n<span style=\"text-decoration:none !important; background-color:#a61e58; color:white; padding:4px 13px; font-size:12px; font-weight:bold; position:relative; top:10px; z-index:1; left:11px;\">\u95a2\u9023\u8a18\u4e8b<\/span>\n<div class=\"blog-card\"><a target=\"_blank\" href=\"https:\/\/www.bold.ne.jp\/engineer-club\/java-replace\" style=\"text-decoration:none;\">\n    <div class=\"blog-card-thumbnail\"><img src='https:\/\/www.bold.ne.jp\/engineer-club\/wp-content\/uploads\/2018\/10\/shutterstock_568617811-600x366.jpg' alt='Java\u306eString.replace\u3068\u306f\uff1f\u6587\u5b57\u30fb\u6587\u5b57\u5217\u3092\u7f6e\u63db\u3059\u308b\u305f\u3081\u306eString.replace\u306e\u4f7f\u3044\u65b9' width=160 height=98 \/><\/div>\n    <div class=\"blog-card-content\">\n        <div class=\"blog-card-title\">Java\u306eString.replace\u3068\u306f\uff1f\u6587\u5b57\u30fb\u6587\u5b57\u5217\u3092\u7f6e\u63db\u3059\u308b\u305f\u3081\u306eString.replace\u306e\u4f7f\u3044\u65b9 <\/div>\n        <span style=\"font-size: 12px; font-weight: normal; position:relative; color:#666;\"><i class=\"fa fa-clock-o\"><\/i>&nbsp;2025\/09\/17<\/span>\n    <\/div>\n<div class=\"clear\"><\/div>\n<\/a><\/div>\n\n<span style=\"text-decoration:none !important; background-color:#a61e58; color:white; padding:4px 13px; font-size:12px; font-weight:bold; position:relative; top:10px; z-index:1; left:11px;\">\u95a2\u9023\u8a18\u4e8b<\/span>\n<div class=\"blog-card\"><a target=\"_blank\" href=\"https:\/\/www.bold.ne.jp\/engineer-club\/java-string-replaceall\" style=\"text-decoration:none;\">\n    <div class=\"blog-card-thumbnail\"><img src='https:\/\/www.bold.ne.jp\/engineer-club\/wp-content\/uploads\/2018\/10\/shutterstock_568617811-600x366.jpg' alt='Java\u306eString.replaceAll\u3068\u306f\uff1f\u30b9\u30de\u30fc\u30c8\u306b\u6587\u5b57\u5217\u7f6e\u63db\u3059\u308b\u305f\u3081\u306ereplaceAll\u306e\u4f7f\u3044\u65b9' width=160 height=98 \/><\/div>\n    <div class=\"blog-card-content\">\n        <div class=\"blog-card-title\">Java\u306eString.replaceAll\u3068\u306f\uff1f\u30b9\u30de\u30fc\u30c8\u306b\u6587\u5b57\u5217\u7f6e\u63db\u3059\u308b\u305f\u3081\u306ereplaceAll\u306e\u4f7f\u3044\u65b9 <\/div>\n        <span style=\"font-size: 12px; font-weight: normal; position:relative; color:#666;\"><i class=\"fa fa-clock-o\"><\/i>&nbsp;2025\/09\/17<\/span>\n    <\/div>\n<div class=\"clear\"><\/div>\n<\/a><\/div>\n<h4>\uff12-\uff14-\uff12\uff0e\u6587\u5b57\u5217\u306e\u5927\u6587\u5b57\u30fb\u5c0f\u6587\u5b57\u5909\u63db\u3092\u3059\u308b<span>toLowerCase\/toUpperCase<\/span><\/h4>\n<p>\u6587\u5b57\u5217\u306e\u5927\u6587\u5b57\u3001\u5c0f\u6587\u5b57\u3092\u5909\u63db\u3059\u308b\u306b\u306f\u3001<span>String.toLowerCase\/toUpperCase<\/span>\u3092\u4f7f\u3046\u3068\u3001\u5909\u63db\u3055\u308c\u305f<span>String<\/span>\u304c\u623b\u308a\u307e\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">String str1 = \"ABC\";\r\nString str2 = str1.toLowerCase();\r\nString str3 = str1.toUpperCase();\r\nSystem.out.println(str2); \/\/ \u2192 abc\r\nSystem.out.println(str3); \/\/ \u2192 ABC<\/pre>\n<h4>\uff12-\uff14-\uff13\uff0e\u6587\u5b57\u5217\u306e\u7a7a\u767d\u6587\u5b57\u3092\u524a\u9664\u3059\u308b<span>trim<\/span><\/h4>\n<p>\u6587\u5b57\u5217\u306e\u524d\u5f8c\u306b\u3042\u308b\u7a7a\u767d\u6587\u5b57\u3092\u524a\u9664\u3059\u308b\u306b\u306f\u3001<span>String.trim<\/span>\u3092\u4f7f\u3044\u307e\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">String str = \" ABC \";\r\nString trimmed = str.trim();\r\nSystem.out.println(trimmed); \/\/ \u2192 \"ABC\"<\/pre>\n<p>\u305f\u3060\u3057\u3001<span>trim<\/span>\u306f\u3044\u308f\u3086\u308b\u5168\u89d2\u7a7a\u767d\u3092\u7a7a\u767d\u3068\u3057\u3066\u8a8d\u8b58\u3057\u3066\u304f\u308c\u305a\u3001\u524a\u9664\u306f\u3055\u308c\u307e\u305b\u3093\u306e\u3067\u3001\u5fc5\u8981\u306a\u3089\u81ea\u5206\u3067\u51e6\u7406\u3092\u4f5c\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">String str = \"\u3000ABC\u3000\"; \/\/ ABC\u306e\u524d\u5f8c\u306b\u5168\u89d2\u7a7a\u767d\u3042\u308a\r\nString trimmed = str.trim();\r\nSystem.out.println(trimmed); \/\/ \u2192 \"\u3000ABC\u3000\"\u3001trim\u306f\u5168\u89d2\u7a7a\u767d\u3092\u524a\u9664\u3057\u3066\u304f\u308c\u306a\u3044<\/pre>\n<p>\u306a\u304a\u3001\u5168\u89d2\u7a7a\u767d\u306b\u3082\u5bfe\u5fdc\u3057\u305f<span>trim<\/span>\u3068\u3057\u3066\u3001<span>Java 11<\/span>\u3067<span>String.strip<\/span>\u3068\u3044\u3046\u30e1\u30bd\u30c3\u30c9\u304c\u8ffd\u52a0\u3055\u308c\u307e\u3057\u305f\u3002\u305d\u308c\u306b\u3064\u3044\u3066\u306f\u5f8c\u8ff0\u3057\u307e\u3059\u3002<\/p>\n<h3><span id=\"i-3\">\uff12-\uff15\uff0e\u6587\u5b57\u5217\u3092\u7e4b\u3052\u308b\u30fb\u5206\u5272\u3059\u308b<\/span><\/h3>\n<h4>\uff12-\uff15-\uff11\uff0e\u6587\u5b57\u5217\u3092\u5206\u5272\u3059\u308b<span>split<\/span><\/h4>\n<p>String\u3092\u4f55\u304b\u306e\u6587\u5b57\u5217\u3067\u5206\u5272\u3059\u308b\u306b\u306f\u3001<span>String.split<\/span>\u3092\u4f7f\u3044\u307e\u3059\u3002<span>split<\/span>\u3092\u547c\u3073\u51fa\u3059\u3068\u3001\u5206\u5272\u3057\u305f\u7d50\u679c\u306e<span>String<\/span>\u306e\u914d\u5217\u304c\u623b\u3063\u3066\u304d\u307e\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">String str = \"\u3042,\u3044,\u3046\";\r\nString[] splitted = str.split(\",\"); \/\/ \u2192 [\"\u3042\", \"\u3044\", \"\u3046\"]\r\nSystem.out.println(splitted.length); \/\/ \u2192 3\r\nSystem.out.println(splitted[0]); \/\/ \u2192 \u3042\r\nSystem.out.println(splitted[1]); \/\/ \u2192 \u3044\r\nSystem.out.println(splitted[2]); \/\/ \u2192 \u3046<\/pre>\n<p>split\u306e\u4e00\u756a\u76ee\u306e\u5f15\u6570\u306f\u3001<span>matches<\/span>\u3068\u540c\u3058\u304f\u6b63\u898f\u8868\u73fe\u3068\u547c\u3070\u308c\u308b\u30d1\u30bf\u30fc\u30f3\u3092\u6307\u5b9a\u3059\u308b\u3082\u306e\u3067\u3001\u6587\u5b57\u5217\u306e\u5206\u5272\u6761\u4ef6\u3092\u304b\u306a\u308a\u67d4\u8edf\u306b\u6307\u5b9a\u3067\u304d\u308b\u306e\u3067\u3059\u3002<\/p>\n<p>String.split\u306b\u3064\u3044\u3066\u306f\u3001\u4ee5\u4e0b\u306e\u8a18\u4e8b\u3082\u53c2\u7167\u3057\u3066\u304f\u3060\u3055\u3044\u3002<\/p>\n\n<span style=\"text-decoration:none !important; background-color:#a61e58; color:white; padding:4px 13px; font-size:12px; font-weight:bold; position:relative; top:10px; z-index:1; left:11px;\">\u95a2\u9023\u8a18\u4e8b<\/span>\n<div class=\"blog-card\"><a target=\"_blank\" href=\"https:\/\/www.bold.ne.jp\/engineer-club\/java-split\" style=\"text-decoration:none;\">\n    <div class=\"blog-card-thumbnail\"><img src='https:\/\/www.bold.ne.jp\/engineer-club\/wp-content\/uploads\/2018\/10\/shutterstock_568617811-600x366.jpg' alt='Java\u306esplit\u3068\u306f\uff1f\u6587\u5b57\u5217\u3092\u5206\u5272\u3059\u308bsplit\u306e\u4f7f\u3044\u65b9\u3010\u30b5\u30f3\u30d7\u30eb\u4ed8\u304d\u3011' width=160 height=98 \/><\/div>\n    <div class=\"blog-card-content\">\n        <div class=\"blog-card-title\">Java\u306esplit\u3068\u306f\uff1f\u6587\u5b57\u5217\u3092\u5206\u5272\u3059\u308bsplit\u306e\u4f7f\u3044\u65b9\u3010\u30b5\u30f3\u30d7\u30eb\u4ed8\u304d\u3011 <\/div>\n        <span style=\"font-size: 12px; font-weight: normal; position:relative; color:#666;\"><i class=\"fa fa-clock-o\"><\/i>&nbsp;2025\/09\/17<\/span>\n    <\/div>\n<div class=\"clear\"><\/div>\n<\/a><\/div>\n<p>\u306a\u304a\u3001\u6587\u5b57\u5217\u3092\u6539\u884c\u6587\u5b57\u3067\u5206\u5272\u3057\u305f\u3044\u3060\u3051\u306a\u3089\u3001<span>Java 11<\/span>\u4ee5\u964d\u3067\u306f<span>String.lines<\/span>\u304c\u4f7f\u3048\u307e\u3059\u3002\u3053\u3061\u3089\u306e\u4f7f\u3044\u65b9\u306f\u5f8c\u8ff0\u3057\u307e\u3059\u3002<\/p>\n<h4>\uff12-\uff15-\uff12\uff0e\u6587\u5b57\u5217\u3092<span>+<\/span>\u6f14\u7b97\u5b50\u3067\u7e4b\u3052\u308b<\/h4>\n<p>String\u540c\u58eb\u3092\u7e4b\u3052\u308b\u306b\u306f\u3001<span>+<\/span>\u6f14\u7b97\u5b50\u3092\u4f7f\u3046\u306e\u304c\u7c21\u5358\u3067\u3059\u3002<span>String<\/span>\u540c\u58eb\u3078\u306e<span>+<\/span>\u6f14\u7b97\u5b50\u306e\u7d50\u679c\u306f\u3001\u7e4b\u304e\u5408\u308f\u305b\u305f\u6587\u5b57\u5217\u3092\u6301\u3064\u3001<span>String<\/span>\u306e\u65b0\u3057\u3044\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3067\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">String str1 = \"\u3042\u3044\u3046\u3048\u304a\";\r\nString str2 = \"ABCD\";\r\nString str3 = str1 + str2;\r\nString str4 = str1 + \"1234\" + str2;\r\nSystem.out.println(str3); \/\/ \u2192 \u3042\u3044\u3046\u3048\u304aABCD\r\nSystem.out.println(str4); \/\/ \u2192 \u3042\u3044\u3046\u3048\u304a1234ABCD<\/pre>\n<p>\u3082\u3057\u81ea\u5206\u81ea\u8eab\u306e\u6587\u5b57\u5217\u3092\u7e70\u308a\u8fd4\u3057\u3066\u7e4b\u3052\u305f\u3044\u5834\u5408\u306f\u3001<span>Java 11<\/span>\u4ee5\u964d\u3067\u306f<span>for<\/span>\u6587\u3092\u4f7f\u3046\u4ee3\u308f\u308a\u306b<span>String.repeat<\/span>\u304c\u4f7f\u3048\u307e\u3059\u3002\u8907\u6570\u306e<span>String<\/span>\u3092\u4f55\u304b\u306e\u6587\u5b57\u3067\u7e4b\u3052\u308b\u306a\u3089\u3001<span>Java 8<\/span>\u4ee5\u964d\u3067\u306f<span>String.join<\/span>\u304c\u4f7f\u3048\u307e\u3059\u3002\u3053\u308c\u3089\u306e\u4f7f\u3044\u65b9\u306f\u5f8c\u8ff0\u3057\u307e\u3059\u3002<\/p>\n<p>\u306a\u304a\u3001<span>+<\/span>\u6f14\u7b97\u5b50\u306f<span>Java<\/span>\u3067\u306f\u304b\u306a\u308a\u7279\u5225\u306a\u6f14\u7b97\u5b50\u3067\u3001\u8db3\u3057\u5408\u308f\u305b\u308b\u5bfe\u8c61\u304c\u4f55\u304b\u3067\u52d5\u304d\u304c\u5909\u308f\u308a\u307e\u3059\u3002\u3053\u306e\u52d5\u304d\u65b9\u3092\u7406\u89e3\u3059\u308b\u306b\u306f<span>Object.toString<\/span>\u3068\u3044\u3046\u30e1\u30bd\u30c3\u30c9\u3092\u77e5\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u304c\u3001\u3053\u306e\u8a18\u4e8b\u3067\u304a\u4f1d\u3048\u3057\u3088\u3046\u3068\u3057\u3066\u3044\u308b\u7bc4\u56f2\u3092\u8d85\u3048\u307e\u3059\u306e\u3067\u3001\u8a18\u8f09\u306f\u3057\u307e\u305b\u3093\u3002<\/p>\n<h4>\uff12-\uff15-\uff13\uff0e\u6587\u5b57\u5217\u3092<span>concat<\/span>\u3067\u7e4b\u3052\u308b<\/h4>\n<p>String.concat\u306f\u3001\u81ea\u5206\u81ea\u8eab\u304c\u6301\u3064\u6587\u5b57\u5217\u3068\u5f15\u6570\u306e<span>String<\/span>\u306e\u6587\u5b57\u5217\u3092\u7e4b\u304e\u5408\u308f\u305b\u305f\u3001\u65b0\u3057\u3044<span>String<\/span>\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u623b\u3057\u307e\u3059\u3002<span>concat<\/span>\u306f<span>concatenate<\/span>\u306e\u7565\u3067\u3001\u7e4b\u3052\u308b\u3068\u3044\u3046\u610f\u5473\u3067\u3059\u3002<span>+<\/span>\u6f14\u7b97\u5b50\u3068\u306e\u4f7f\u3044\u5206\u3051\u306f\u3042\u307e\u308a\u6c17\u306b\u3057\u306a\u304f\u3066\u3082\u826f\u3044\u306e\u3067\u3001\u597d\u304d\u306a\u65b9\u3092\u4f7f\u3063\u3066\u304f\u3060\u3055\u3044\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">String str1 = \"\u3042\u3044\u3046\u3048\u304a\";\r\nString str2 = \"ABCD\";\r\nString str3 = str1.concat(str2);\r\nString str4 = str1.concat(str2).concat(\"1234\");\r\nSystem.out.println(str3); \/\/ \u2192 \u3042\u3044\u3046\u3048\u304aABCD\r\nSystem.out.println(str4); \/\/ \u2192 \u3042\u3044\u3046\u3048\u304aABCD1234<\/pre>\n<h3><span id=\"i-4\">\uff12-\uff16\uff0e\u6587\u5b57\u5217\u3092\u6bd4\u8f03\u3059\u308b<\/span><\/h3>\n<h4>\uff12-\uff16-\uff11\uff0e\u3010\u8d85\u91cd\u8981\u3011\u6587\u5b57\u5217\u540c\u58eb\u304c\u540c\u3058\u304b\u8abf\u3079\u308b<span>equals<\/span><\/h4>\n<p>String\u540c\u58eb\u304c\u540c\u3058\u304b\u8abf\u3079\u308b\u306b\u306f\u3001<span>String.equals<\/span>\u3092\u300c\u5fc5\u305a\u300d\u4f7f\u3044\u307e\u3057\u3087\u3046\u3002\u6bd4\u8f03\u6f14\u7b97\u5b50<span> == <\/span>\u3092\u4f7f\u3046\u3079\u304d\u30b1\u30fc\u30b9\u306f\u3001\u307b\u307c\u8003\u3048\u3089\u308c\u307e\u305b\u3093\u3002<\/p>\n<p>\u3053\u3053\u3067<span>String<\/span>\u540c\u58eb\u304c\u300c\u540c\u3058\u300d\u3067\u3042\u308b\u3068\u306f\u3001<span>String<\/span>\u304c\u6301\u3064\u6587\u5b57\u5217\u304c\u540c\u3058\u3060\u3068\u3044\u3046\u3053\u3068<span>\u2026<\/span>\u305d\u308c\u304c\u81ea\u7136\u3067\u3057\u3087\u3046\u3002\u3064\u307e\u308a\u3001<span>&#8220;ABCD&#8221;<\/span>\u3068<span>&#8220;ABCD&#8221;<\/span>\u306f\u540c\u3058\u3067\u3042\u308a\u3001<span>&#8220;ABCD&#8221;<\/span>\u3068<span>&#8220;<\/span>\u3042\u3044\u3046\u3048\u304a<span>&#8220;<\/span>\u306f\u9055\u3046\u3068\u3044\u3046\u3053\u3068\u3067\u3001\u307e\u3042\u3001\u5f53\u305f\u308a\u524d\u3067\u3059\u3088\u306d\u3002<\/p>\n<p>\u305f\u3060\u3001<span>Java<\/span>\u3067\u306f\u305d\u306e\u5224\u65ad\u306b<span>==<\/span>\u3092\u4f7f\u3063\u3066\u306f\u3044\u3051\u307e\u305b\u3093\u3002\u305f\u307e\u305f\u307e\u4e0a\u624b\u304f\u3044\u304f\u3053\u3068\u3082\u3042\u308a\u307e\u3059\u304c\u3001\u99c4\u76ee\u306a\u3053\u3068\u304c\u307b\u3068\u3093\u3069\u3067\u3059\u3002\u78ba\u5b9f\u306b\u6bd4\u8f03\u3059\u308b\u306a\u3089\u3001<span>String<\/span>\u304c\u6301\u3064\u6587\u5b57\u5217\u304c\u540c\u3058\u304b\u5224\u65ad\u3057\u3066\u304f\u308c\u308b<span>equals<\/span>\u3092\u4f7f\u3044\u307e\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">String str1 = \"ABCD\";\r\nString str2 = \"ABCD\";\r\nString str3 = new String(\"ABCD\");\r\n\r\nif (str1 == str2) {\r\n\tSystem.out.println(\"str1 == str2\"); \/\/ \u3053\u3061\u3089\r\n} else {\r\n\tSystem.out.println(\"str1 != str2\");\r\n}\r\n\r\nif (str1 == str3) {\r\n\tSystem.out.println(\"str1 == str3\");\r\n} else {\r\n\tSystem.out.println(\"str1 != str3\"); \/\/ \u3053\u3061\u3089\u306b\u306a\u308b!!\r\n}\r\n\r\nif (str1.equals(str3)) {\r\n\tSystem.out.println(\"str1 equals str3\"); \/\/ \u3053\u3061\u3089\r\n} else {\r\n\tSystem.out.println(\"str1 not equals str3\");\r\n}<\/pre>\n<p>==\u306f\u3001\u53c2\u7167\u578b\u5909\u6570\u3078\u4f7f\u3063\u305f\u5834\u5408\u306f\u3001\u540c\u3058\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u304b\u3069\u3046\u304b\u3092\u8abf\u3079\u308b\u3053\u3068\u306b\u306a\u308a\u307e\u3059\u3002<span>String<\/span>\u304c\u6301\u3063\u3066\u3044\u308b\u6587\u5b57\u5217\u540c\u58eb\u3092\u8abf\u3079\u3066\u306f\u304f\u308c\u306a\u3044\u306e\u3067\u3059\u3002\u524d\u8ff0\u306e\u30b5\u30f3\u30d7\u30eb\u3067\u306f\u3001\u4e09\u756a\u76ee\u306e<span>String<\/span>\u306f\u65b0\u3057\u304f<span>new<\/span>\u3057\u3066\u3044\u307e\u3059\u306e\u3067\u3001<span>1<\/span>\u756a\u76ee\u3001<span>2<\/span>\u756a\u76ee\u306e<span>String<\/span>\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3068\u306f\u5b9f\u306f\u5225\u7269\u306a\u306e\u3067\u3059\u3002<\/p>\n<h4>\uff12-\uff16-\uff12\uff0e\u6587\u5b57\u5217\u540c\u58eb\u306e\u5927\u5c0f\u3092\u6bd4\u8f03\u3059\u308b<span>compareTo\/compareToIgnoreCase<\/span><\/h4>\n<p>\u6587\u5b57\u5217\u540c\u58eb\u3092\u6bd4\u8f03\u3057\u3066\u3001\u3069\u3061\u3089\u306e\u65b9\u304c\u300c\u5c0f\u3055\u3044\u300d\u300c\u540c\u3058\u300d\u300c\u5927\u304d\u3044\u300d\u3092\u5224\u65ad\u3057\u305f\u3044\u6642\u304c\u3042\u308a\u307e\u3059\u3002\u4f8b\u3048\u3070\u3001\u30bd\u30fc\u30c8\u3092\u3057\u305f\u3044\u6642\u3067\u3059\u3002<\/p>\n<p>\u305d\u3093\u306a\u6642\u306b\u306f\u3001<span>String.compareTo<\/span>\u3092\u4f7f\u3044\u307e\u3059\u3002<span>compareTo<\/span>\u306e\u7d50\u679c\u3067\u306f\u3001\u5c0f\u3055\u3044<span>(-1<\/span>\u4ee5\u4e0b<span>)<\/span>\u3001\u540c\u3058<span>(0)<\/span>\u3001\u5927\u304d\u3044<span>(1<\/span>\u4ee5\u4e0a<span>)<\/span>\u3092\u5224\u65ad\u3057\u305f\u7d50\u679c\u304c\u3001<span>int<\/span>\u3068\u3057\u3066\u623b\u3063\u3066\u304d\u307e\u3059\u3002\u3053\u308c\u306f\u3001<span>compareTo<\/span>\u3092\u5b9f\u884c\u3059\u308b<span>String<\/span>\u304b\u3089\u898b\u3066\u3001\u6bd4\u8f03\u5148\u3088\u308a\u3082\u81ea\u5206\u304c\u5c0f\u3055\u3044\u3001\u540c\u3058\u3001\u5927\u304d\u3044\u3092\u5224\u65ad\u3057\u305f\u7d50\u679c\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">String str1 = \"ABC\";\r\nString str2 = \"DEF\";\r\nint compared = str1.compareTo(str2);\r\nSystem.out.println(compared); \/\/ \u2192 -1\u4ee5\u4e0b\u306e\u5024\u3001'A'\u306f'D'\u3088\u308a\u300c\u5c0f\u3055\u3044\u300d\u305f\u3081<\/pre>\n<p>\u3055\u3089\u306b\u3001\u6587\u5b57\u306e\u5927\u6587\u5b57\u30fb\u5c0f\u6587\u5b57\u3092\u540c\u3058\u3082\u306e\u3068\u3057\u3066\u6bd4\u8f03\u3092\u3057\u305f\u3044\u306a\u3089\u3001<span>compareToIgnoreCase<\/span>\u3092\u4f7f\u3046\u3068\u3044\u3044\u3067\u3057\u3087\u3046\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">String str1 = \"ABC\";\r\nString str2 = \"abc\";\r\nint compared = str1.compareToIgnoreCase(str2);\r\nSystem.out.println(compared); \/\/ \u2192 0\u3001\"ABC\"\u306f\"abc\"\u3068\u5927\u6587\u5b57\u5c0f\u6587\u5b57\u3092\u7121\u8996\u3059\u308c\u3070\u540c\u4e00\u3067\u3042\u308b\u305f\u3081\u3002<\/pre>\n<p>compareTo\u3084\u3001<span>compareTo<\/span>\u3092\u4f7f\u3063\u305f\u30bd\u30fc\u30c8\u51e6\u7406\u306b\u3064\u3044\u3066\u306f\u3001\u4ee5\u4e0b\u306e\u8a18\u4e8b\u3082\u53c2\u7167\u3057\u3066\u304f\u3060\u3055\u3044\u3002<\/p>\n\n<span style=\"text-decoration:none !important; background-color:#a61e58; color:white; padding:4px 13px; font-size:12px; font-weight:bold; position:relative; top:10px; z-index:1; left:11px;\">\u95a2\u9023\u8a18\u4e8b<\/span>\n<div class=\"blog-card\"><a target=\"_blank\" href=\"https:\/\/www.bold.ne.jp\/engineer-club\/java-compareto\" style=\"text-decoration:none;\">\n    <div class=\"blog-card-thumbnail\"><img src='https:\/\/www.bold.ne.jp\/engineer-club\/wp-content\/uploads\/2018\/10\/shutterstock_568617811-600x366.jpg' alt='Java\u306ecompareTo\u3068\u306f\uff1f\u30bd\u30fc\u30c8\u3092\u81ea\u7531\u81ea\u5728\u306b\u64cd\u308b\u305f\u3081\u306ecompareTo\u306e\u4f7f\u3044\u65b9' width=160 height=98 \/><\/div>\n    <div class=\"blog-card-content\">\n        <div class=\"blog-card-title\">Java\u306ecompareTo\u3068\u306f\uff1f\u30bd\u30fc\u30c8\u3092\u81ea\u7531\u81ea\u5728\u306b\u64cd\u308b\u305f\u3081\u306ecompareTo\u306e\u4f7f\u3044\u65b9 <\/div>\n        <span style=\"font-size: 12px; font-weight: normal; position:relative; color:#666;\"><i class=\"fa fa-clock-o\"><\/i>&nbsp;2025\/09\/17<\/span>\n    <\/div>\n<div class=\"clear\"><\/div>\n<\/a><\/div>\n<h2><span id=\"String-2\">\uff13\uff0e\u3010\u5fdc\u7528\u3011<span>String<\/span>\u3092\u6d3b\u7528\u3059\u308b\u305f\u3081\u306b\u305c\u3072\u77e5\u3063\u3066\u304a\u304d\u305f\u3044\u3053\u3068<\/span><\/h2>\n<p>\u3055\u3066\u3001\u3053\u3053\u307e\u3067\u304c<span>String<\/span>\u3092\u4f7f\u3046\u4e0a\u3067\u305c\u3072\u62bc\u3055\u3048\u3066\u304a\u304d\u305f\u3044\u3053\u3068\u3067\u3059\u3002\u305d\u308c\u3067\u3082\u306a\u304b\u306a\u304b\u30dc\u30ea\u30e5\u30fc\u30e0\u304c\u3042\u308a\u307e\u3057\u305f\u304c\u3001\u5927\u4e08\u592b\u3067\u3057\u305f\u304b<span>? <\/span>\u30b5\u30f3\u30d7\u30eb\u30d7\u30ed\u30b0\u30e9\u30e0\u3092\u81ea\u5206\u3067\u3082\u66f8\u3044\u3066\u52d5\u304b\u3057\u3066\u307f\u3066\u3001\u3086\u3063\u304f\u308a\u3058\u3063\u304f\u308a<span>String<\/span>\u306e\u4f7f\u3044\u65b9\u3092\u7406\u89e3\u3057\u3066\u304f\u3060\u3055\u3044\u3002<\/p>\n<p>\u3053\u3053\u304b\u3089\u306f\u3001<span>Java<\/span>\u3067<span>String<\/span>\u3092\u3088\u308a\u6d3b\u7528\u3059\u308b\u305f\u3081\u306b\u3001\u305c\u3072\u77e5\u3063\u3066\u304a\u304d\u305f\u3044\u3053\u3068\u3092\u304a\u4f1d\u3048\u3057\u307e\u3059\u3002<\/p>\n<h3><span id=\"-String-2\">\uff13-\uff11\uff0eString\u306f\u81ea\u5206\u81ea\u8eab\u306e\u6587\u5b57\u5217\u3092\u5909\u3048\u3089\u308c\u306a\u3044<\/span><\/h3>\n<p>String\u306f\u3001\u81ea\u5206\u81ea\u8eab\u304c\u6301\u3063\u3066\u3044\u308b\u6587\u5b57\u5217\u3092\u5909\u3048\u3089\u308c\u307e\u305b\u3093\u3002\u3053\u308c\u306f\u5fc5\u305a\u899a\u3048\u3066\u304a\u304d\u307e\u3057\u3087\u3046\u3002<\/p>\n<p>Java\u3067\u306f\u3001\u6587\u5b57\u5217\u306e\u4e2d\u8eab\u3092\u5909\u3048\u305f\u3044\u306e\u306a\u3089\u3001\u4e2d\u8eab\u304c\u5909\u308f\u3063\u3066\u3044\u308b<span>String<\/span>\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u5225\u306b\u65b0\u3057\u304f\u4f5c\u308b\u3057\u304b\u306a\u3044\u306e\u3067\u3059\u3002\u4eca\u307e\u3067\u51fa\u3066\u304d\u305f\u4e2d\u3067\u306f<span>String.replace<\/span>\u3084<span>trim<\/span>\u3001<span>concat<\/span>\u304c\u3044\u3044\u4f8b\u3067\u3001<span>substring<\/span>\u3082\u4f3c\u305f\u8003\u3048\u65b9\u3067\u3059\u306d\u3002<\/p>\n<p>\u3053\u306e\u3088\u3046\u306a\u3001\u6301\u3063\u3066\u3044\u308b\u60c5\u5831\u3092\u5909\u3048\u3089\u308c\u306a\u3044\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u3001\u4e0d\u5909<span>(Immutable)<\/span>\u306a\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3068\u547c\u3076\u3053\u3068\u3082\u3042\u308a\u307e\u3059\u3002<span>Java<\/span>\u3067\u306e\u4e0d\u5909\u306a\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u306f\u3001\u30d7\u30ea\u30df\u30c6\u30a3\u30d6\u578b\u306e\u30e9\u30c3\u30d1\u30fc\u30af\u30e9\u30b9<span>(Integer<\/span>\u3084<span>Boolean<\/span>\u306a\u3069<span>)<\/span>\u304c\u4ee3\u8868\u4f8b\u3067\u3059\u3002\u305d\u306e\u4ed6\u306b\u3082<span>LocalDate<\/span>\u3084<span>Path<\/span>\u306a\u3069\u3001\u8fd1\u5e74<span>API<\/span>\u3078\u8ffd\u52a0\u3055\u308c\u305f\u30af\u30e9\u30b9\u306f\u305d\u306e\u50be\u5411\u304c\u5f37\u3044\u3067\u3059\u3002<\/p>\n<h4>\uff13-\uff11-\uff11\uff0eString\u306e\u5185\u5bb9\u3092\u5909\u3048\u3089\u308c\u306a\u3044\u306e\u306f\u30ef\u30b1\u304c\u3042\u308b<\/h4>\n<p>\u306a\u305c<span>Java<\/span>\u3067\u306f<span>String<\/span>\u306e\u5185\u5bb9\u3092\u5909\u3048\u3089\u308c\u306a\u3044\u306e\u3067\u3057\u3087\u3046\u304b\u3002\u4f8b\u3048\u3070\u3001<span>C<\/span>\u8a00\u8a9e\u3067\u6587\u5b57\u5217\u3068\u3057\u3066<span>char<\/span>\u306e\u914d\u5217\u3092\u4f7f\u3046\u306a\u3089\u3001\u4e2d\u8eab\u306f\u81ea\u7531\u306b\u66f8\u304d\u63db\u3048\u3089\u308c\u307e\u3059\u3088\u306d\u3002<\/p>\n<p>\u4ee5\u4e0b\u304c<span>String<\/span>\u306e\u5185\u5bb9\u3092\u5909\u3048\u3089\u308c\u306a\u3044\u7406\u7531\u3068\u3057\u3066\u6319\u3052\u3089\u308c\u308b\u3082\u306e\u3067\u3059\u3002<\/p>\n<ul>\n<li>\u30e1\u30e2\u30ea\u306e\u5229\u7528\u3092\u52b9\u7387\u5316\u3059\u308b\uff1a\u540c\u3058\u6587\u5b57\u5217\u306a\u3089\u540c\u3058\u30e1\u30e2\u30ea\u9818\u57df\u3092\u4f7f\u3063\u3066\u30c7\u30fc\u30bf\u3092\u5171\u6709\u3067\u304d\u308b\u306e\u3067\u3001\u30e1\u30e2\u30ea\u5168\u4f53\u3092\u52b9\u7387\u7684\u306b\u4f7f\u3048\u307e\u3059\u3002<\/li>\n<li>\u5b89\u5168\u6027\u3092\u9ad8\u3081\u308b\uff1a\u4f8b\u3048\u3070\u3001\u30d1\u30b9\u30ef\u30fc\u30c9\u306a\u3069\u3092\u6301\u3063\u3066\u3044\u308b<span>String<\/span>\u306e\u5185\u5bb9\u3092\u3001\u8ab0\u304b\u306b\u3044\u3064\u306e\u9593\u306b\u304b\u3053\u3063\u305d\u308a\u5909\u3048\u3089\u308c\u3066\u306f\u56f0\u308a\u307e\u3059\u3088\u306d\u3002<\/li>\n<li>\u540c\u671f\u3092\u4e0d\u8981\u3068\u3059\u308b\uff1a\u5185\u5bb9\u3092\u5909\u3048\u3089\u308c\u308b\u3068\u3001\u30de\u30eb\u30c1\u30b9\u30ec\u30c3\u30c9\u74b0\u5883\u306a\u3069\u3067<span>String<\/span>\u3078\u540c\u6642\u306b\u30a2\u30af\u30bb\u30b9\u304c\u3042\u308b\u72b6\u614b\u3067\u306e\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u304c\u96e3\u3057\u304f\u306a\u308a\u307e\u3059\u3002<\/li>\n<\/ul>\n<p>\u307e\u305f\u3001\u6587\u5b57\u5217\u3092\u5b9f\u88c5\u3059\u308b\u306e\u306b\u4f7f\u308f\u308c\u308b\u914d\u5217\u3084\u3001\u305d\u308c\u3089\u3092\u4f7f\u3046\u305f\u3081\u306e\u3044\u308f\u3086\u308b\u30dd\u30a4\u30f3\u30bf\u306e\u64cd\u4f5c\u306f\u3001\u8272\u3005\u306a\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u8a00\u8a9e\u3067\u306e\u30bb\u30ad\u30e5\u30ea\u30c6\u30a3\u554f\u984c\u306e\u6839\u672c\u539f\u56e0\u3067\u3059\u3002\u305d\u3046\u3044\u3046\u3082\u306e\u3092<span>Java<\/span>\u306e\u6587\u5b57\u5217\u64cd\u4f5c\u306b\u6301\u3061\u8fbc\u307f\u305f\u304f\u306a\u304b\u3063\u305f\u306e\u304b\u3082\u3057\u308c\u307e\u305b\u3093\u3002<\/p>\n<h4>\uff13-\uff11-\uff12\uff0e\u6587\u5b57\u5217\u30ea\u30c6\u30e9\u30eb\u306f\u540c\u3058<span>String<\/span>\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u306b\u306a\u308b<\/h4>\n<p>Java\u4e0a\u3067\u306e\u6587\u5b57\u5217\u30ea\u30c6\u30e9\u30eb\u3001\u3064\u307e\u308a<span>&#8220;&#8221;<\/span>\u3067\u304f\u304f\u3063\u3066\u4f5c\u3063\u305f<span>String<\/span>\u306e\u3053\u3068\u3067\u3059\u304c\u3001\u3053\u308c\u306f\u540c\u3058\u6587\u5b57\u5217\u306a\u3089<span>Java<\/span>\u306e\u30e1\u30e2\u30ea\u4e0a\u3067\u3082\u540c\u3058<span>String<\/span>\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3067\u3059\u3002\u3064\u307e\u308a\u3001<span>String.equals<\/span>\u306e\u9805\u3067\u3082\u4f8b\u793a\u3057\u305f\u3068\u304a\u308a\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u6bd4\u8f03\u6f14\u7b97\u5b50<span>==<\/span>\u3067\u3082\u7b49\u3057\u3044\u3001\u3059\u306a\u308f\u3061\u540c\u3058\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u306b\u306a\u308b\u306e\u3067\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">String str1 = \"ABCD\";\r\nString str2 = \"ABCD\";\r\n\r\nif (str1 == str1) {\r\n\tSystem.out.println(\"\\\"\\\" == null\"); \/\/ \u3053\u3061\u3089!!\r\n} else {\r\n\tSystem.out.println(\"\\\"\\\" != null\");\r\n}<\/pre>\n<p>\u3053\u3046\u306a\u308b\u306e\u306f\u3001<span>Java<\/span>\u304c\u30e1\u30e2\u30ea\u3092\u52b9\u7387\u7684\u306b\u4f7f\u3044\u305f\u3044\u304b\u3089\u3067\u3059\u3002\u4e00\u3064\u306e\u6587\u5b57\u5217\u30ea\u30c6\u30e9\u30eb\u306b\u56fa\u5b9a\u306e\u30e1\u30e2\u30ea\u9818\u57df\u3092\u4e0e\u3048\u3066\u304a\u3051\u3070\u3001\u540c\u3058\u6587\u5b57\u5217\u30ea\u30c6\u30e9\u30eb\u306b\u5bfe\u3057\u3066\u540c\u3058<span>String<\/span>\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u4f7f\u3044\u307e\u308f\u305b\u307e\u3059\u3002\u3082\u3057\u3001<span>String<\/span>\u306e\u5185\u5bb9\u304c\u81ea\u7531\u306b\u5909\u66f4\u51fa\u6765\u305f\u3068\u3057\u305f\u3089\u3001\u3053\u3046\u306f\u3044\u304b\u306a\u3044\u3067\u3059\u3088\u306d<span>?<\/span><\/p>\n<h3><span id=\"-null82208221\">\uff13-\uff12\uff0enull\u3068<span>&#8220;&#8221;<\/span>\u306f\u9055\u3046\u3082\u306e<\/span><\/h3>\n<p>\u4f8b\u3048\u3070\u3001\u3068\u3042\u308b\u8d85\u30e1\u30b8\u30e3\u30fc\u306a\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u3067\u306f\u3001<span>NULL<\/span>\u3068\u6587\u5b57\u6570<span>0<\/span>\u306e\u6587\u5b57\u5217<span>(&#8221;)<\/span>\u306f\u540c\u3058\u3082\u306e\u3067\u3059\u3002\u3067\u3082<span>Java<\/span>\u3067\u306f\u3001<span>null<\/span>\u3068\u6587\u5b57\u6570<span>0<\/span>\u306e<span>String(&#8220;&#8221;<\/span>\u3001\u3044\u308f\u3086\u308b\u7a7a\u6587\u5b57\u5217<span>)<\/span>\u306f\u9055\u3046\u3082\u306e\u306a\u306e\u3067\u3001\u30d7\u30ed\u30b0\u30e9\u30e0\u4e0a\u3067\u3082\u304d\u3061\u3093\u3068\u533a\u5225\u3092\u3057\u306a\u3051\u308c\u3070\u3044\u3051\u307e\u305b\u3093\u3002<\/p>\n<p>null\u306f\u5909\u6570\u304c<span>String<\/span>\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u6307\u3057\u3066\u3044\u306a\u3044\u72b6\u614b\u3001\u7a7a\u6587\u5b57\u5217\u306f<span>String<\/span>\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u306f\u3042\u308b\u3051\u308c\u3069\u3001\u6301\u3063\u3066\u3044\u308b\u6587\u5b57\u6570\u304c<span>0<\/span>\u306e\u72b6\u614b\u3067\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">String strZero = \"\";\r\nString strNull = null;\r\n\r\nif (strZero == strNull) {\r\n\tSystem.out.println(\"\\\"\\\" == null\");\r\n} else {\r\n\tSystem.out.println(\"\\\"\\\" != null\"); \/\/ \u3053\u3061\u3089!!\r\n}\r\n\r\nif (strZero.equals(strNull)) {\r\n\tSystem.out.println(\"\\\"\\\" equals null\");\r\n} else {\r\n\tSystem.out.println(\"\\\"\\\" not equals null\"); \/\/ \u3053\u3061\u3089!!\r\n}<\/pre>\n<p>\u3067\u3059\u304b\u3089\u3001\u4ed6\u306e<span>Java<\/span>\u30d7\u30ed\u30b0\u30e9\u30de\u3084\u7279\u306b\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u306e\u77e5\u8b58\u304c\u3042\u308b\u4eba\u3068\u4f1a\u8a71\u3092\u3059\u308b\u6642\u306f\u3001\u300c\u30cc\u30eb\u300d\u3068\u304b\u300c\u672a\u8a2d\u5b9a\u300d\u3068\u3044\u3046\u611f\u3058\u306e\u8a00\u8449\u304c\u51fa\u3066\u6765\u305f\u3089\u8981\u6ce8\u610f\u3067\u3059\u3002\u305d\u308c\u3089\u306e\u8a00\u8449\u304c\u610f\u5473\u3059\u308b\u3082\u306e\u304c\u304a\u4e92\u3044\u306b\u9055\u3063\u3066\u3044\u308c\u3070\u3001\u305d\u308c\u3060\u3051\u3067\u30d0\u30b0\u306e\u539f\u56e0\u306b\u306a\u3063\u3066\u3057\u307e\u3044\u307e\u3059\u306e\u3067\u3001\u3057\u3063\u304b\u308a\u3068\u610f\u8b58\u5408\u308f\u305b\u3092\u3057\u307e\u3057\u3087\u3046<span>!!<\/span><\/p>\n<h3><span id=\"-String-3\">\uff13-\uff13\uff0eString\u3068\u4ed6\u306e\u30af\u30e9\u30b9\u3092\u5909\u63db\u3059\u308b<\/span><\/h3>\n<p>String\u3092<span>int<\/span>\u306a\u3069\u306e\u6570\u5024\u306b\u3057\u305f\u308a\u3001\u9006\u306b<span>int<\/span>\u306a\u3069\u3092<span>String<\/span>\u306b\u3057\u305f\u3044\u3053\u3068\u304c\u3042\u308a\u307e\u3059\u3002\u4f8b\u3048\u3070\u3001\u524d\u8005\u306f\u30d5\u30a1\u30a4\u30eb\u306a\u3069\u304b\u3089\u8aad\u307f\u8fbc\u3093\u3060\u5024\u3092\u6570\u5024\u306b\u5909\u63db\u3059\u308b\u6642\u3001\u5f8c\u8005\u306f\u9006\u306b\u30d5\u30a1\u30a4\u30eb\u306a\u3069\u3078\u6570\u5024\u3092\u51fa\u529b\u3059\u308b\u305f\u3081\u306b\u66f8\u5f0f\u3092\u4ed8\u3051\u308b\u5834\u5408\u306a\u3069\u3067\u3059\u3002<\/p>\n<h4>\uff13-\uff13-\uff11\uff0eString\u2192\u4f55\u304b\u306f<span>valueOf<\/span>\u3092\u4f7f\u3046<\/h4>\n<p>\u5909\u63db\u5148\u304c\u30d7\u30ea\u30df\u30c6\u30a3\u30d6\u578b<span>(int\/boolean<\/span>\u7b49<span>)<\/span>\u3001\u3042\u308b\u3044\u306f\u30d7\u30ea\u30df\u30c6\u30a3\u30d6\u578b\u306e\u30e9\u30c3\u30d1\u30fc\u30af\u30e9\u30b9<span>(Integer\/Boolean<\/span>\u7b49<span>)<\/span>\u306a\u3089\u3001\u305d\u308c\u305e\u308c\u306e\u30e9\u30c3\u30d1\u30fc\u30af\u30e9\u30b9\u306e<span>valueOf<\/span>\u3092\u4f7f\u3044\u307e\u3057\u3087\u3046\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">byte b = Byte.valueOf(\"0\");\r\nshort s = Short.valueOf(\"1\");\r\nint i = Integer.valueOf(\"2\");\r\nlong l = Long.valueOf(\"3\");\r\nfloat f = Float.valueOf(\"1.1\");\r\ndouble d = Double.valueOf(\"2.2\");\r\nboolean bl = Boolean.valueOf(\"true\");<\/pre>\n<p>char\u3060\u3051\u306f\u7279\u5225\u3067\u3001<span>String<\/span>\u304c\u5f15\u6570\u306e<span>valueOf<\/span>\u306f\u3042\u308a\u307e\u305b\u3093\u3002<span>String.charAt<\/span>\u3084\u3001<span>toCharArray<\/span>\u3092\u4f7f\u3044\u307e\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">char c = \"\u3042\".charAt(0); \/\/ \u2192 '\u3042'\r\nchar[] chaArr = \"\u3042\u3044\u3046\u3048\u304a\".toCharArray(); \/\/ \u2192 ['\u3042', '\u3044', '\u3046', '\u3048', '\u304a']<\/pre>\n<p>\u307e\u305f\u3001\u8272\u3005\u306a\u30af\u30e9\u30b9\u306e\u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf\u306b\u306f\u3001<span>String<\/span>\u3092\u5f15\u6570\u306b\u53d6\u3063\u3066\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u4f5c\u308b\u4e0a\u3067\u306e\u5143\u60c5\u5831\u3068\u3057\u3066\u89e3\u91c8\u3057\u3066\u304f\u308c\u308b\u3082\u306e\u304c\u3042\u308a\u307e\u3059\u3002\u305d\u308c\u3089\u306e\u30af\u30e9\u30b9\u306e<span>Javadoc<\/span>\u3092\u3088\u304f\u8aad\u3093\u3067\u307f\u308b\u3068\u3001\u8272\u3005\u306a\u767a\u898b\u304c\u3042\u308b\u3068\u601d\u3044\u307e\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">java.math.BigDecimal bd = new java.math.BigDecimal(\"10.1\"); \/\/ \u2192 10.1\u3092\u5024\u306b\u6301\u3064BigDecimal\r\njava.io.File file = new java.io.File(\"\/A\/B\/C.txt\"); \/\/ \u2192 \/A\/B\/C.txt\u3092\u5024\u306b\u6301\u3064File<\/pre>\n<h4>\uff13-\uff12-\uff12\uff0e\u4f55\u304b<span>\u2192String<\/span>\u306f<span>toString<\/span>\u304b\u3001<span>String.valueOf<\/span>\u3092\u4f7f\u3046<\/h4>\n<p>\u5909\u63db\u5143\u304c\u30d7\u30ea\u30df\u30c6\u30a3\u30d6\u578b<span>(int\/boolean<\/span>\u7b49<span>)<\/span>\u3001\u3042\u308b\u3044\u306f\u30d7\u30ea\u30df\u30c6\u30a3\u30d6\u578b\u306e\u30e9\u30c3\u30d1\u30fc\u30af\u30e9\u30b9<span>(Integer\/Boolean<\/span>\u7b49<span>)<\/span>\u306a\u3089\u3001\u305d\u308c\u305e\u308c\u306e\u30e9\u30c3\u30d1\u30fc\u30af\u30e9\u30b9\u306e<span>toString<\/span>\u3092\u4f7f\u3044\u307e\u3057\u3087\u3046\u3002\u3042\u308b\u3044\u306f\u3001<span>String<\/span>\u306b\u3082<span>valueOf<\/span>\u304c\u3042\u308a\u3001\u305d\u3061\u3089\u3067\u5909\u63db\u3057\u3066\u3082\u5927\u4e08\u592b\u3067\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">Byte.toString((byte) 0); \/\/ \u2192 \"0\"\r\nShort.toString((short) 1); \/\/ \u2192 \"1\"\r\nInteger.toString(2); \/\/ \u2192 \"2\"\r\nLong.toString(3); \/\/ \u2192 \"3\"\r\nFloat.toString(1.1f); \/\/ \u2192 \"1.1\"\r\nDouble.toString(2.2d); \/\/ \u2192 \"2.2\"\r\nBoolean.toString(true); \/\/ \u2192 \"true\"\r\nCharacter.toString('c'); \/\/ \u2192 \"c\"<\/pre>\n<pre class=\"prettyprint lang:default decode:true\">String.valueOf((byte) 0); \/\/ \u2192 \"0\"\r\nString.valueOf((short) 1); \/\/ \u2192 \"1\"\r\nString.valueOf(2); \/\/ \u2192 \"2\"\r\nString.valueOf((long) 3); \/\/ \u2192 \"3\"\r\nString.valueOf(1.1f); \/\/ \u2192 \"1.1\"\r\nString.valueOf(2.2d); \/\/ \u2192 \"2.2\"\r\nString.valueOf(true); \/\/ \u2192 \"true\"\r\nString.valueOf('c'); \/\/ \u2192 \"c\"<\/pre>\n<p>\u6570\u5024\u3084\u65e5\u6642\u306a\u3069\u306e\u66f8\u5f0f\u3092\u6307\u5b9a\u3057\u305f\u3044\u306a\u3089\u3001<span>String.format<\/span>\u3084\u3001<span>DecimalFormat<\/span>\u3001<span>SimpleDateFormat(<\/span>\u3042\u308b\u3044\u306f<span>DateTimeFormatter)<\/span>\u306a\u3069\u3092\u4f7f\u3044\u307e\u3059\u3002<span>String.format<\/span>\u306f<span>C<\/span>\u8a00\u8a9e\u3067\u306e<span>sprintf<\/span>\u306e\u4f7f\u3044\u65b9\u306b\u8fd1\u304f\u3001\u66f8\u5f0f\u306e\u30eb\u30fc\u30eb\u3082\u5927\u4f53\u540c\u3058\u306a\u306e\u3067\u3001<span>C<\/span>\u8a00\u8a9e\u306e\u7d4c\u9a13\u304c\u3042\u308c\u3070\u4f7f\u3044\u3084\u3059\u3044\u3067\u3057\u3087\u3046\u3002\u8a73\u7d30\u306f<span>Javadoc<\/span>\u3092\u53c2\u7167\u3057\u3066\u304f\u3060\u3055\u3044\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">String.format(\"%05d\", 1); \/\/ \u2192 \"00001\"\r\nnew java.text.DecimalFormat(\"#,###\").format(1234567); \/\/ \u2192 \"1,234,567\"\r\nnew java.text.SimpleDateFormat(\"yyyy-MM-dd\").format(new java.util.Date()); \/\/ \u2192 \"2019-02-06\"\r\njava.time.format.DateTimeFormatter.ISO_DATE.format(java.time.LocalDate.now()); \/\/ \u2192 \"2019-02-06\"<\/pre>\n<h3><span id=\"-StringBuilder\">\uff13-\uff14\uff0eStringBuilder\u3067\u6587\u5b57\u5217\u3092\u7e4b\u3052\u308b<\/span><\/h3>\n<p>StringBuilder\u3092\u4f7f\u3046\u3068\u3001\u7e4b\u3052\u305f\u3044\u6587\u5b57\u5217\u3092\u4e00\u6642\u7684\u306b\u6e9c\u3081\u3066\u304a\u3044\u3066\u3001\u7d42\u308f\u3063\u305f\u3089\u6587\u5b57\u5217\u5168\u4f53\u306e<span>String<\/span>\u3092\u4f5c\u308c\u307e\u3059\u3002\u7279\u306b\u3001\u30eb\u30fc\u30d7\u51e6\u7406\u3067\u6587\u5b57\u5217\u7d50\u5408\u3092\u3057\u305f\u308a\u3001\u4ed6\u306e\u51e6\u7406\u3068\u306e\u9593\u3067\u7e4b\u3052\u3066\u3044\u308b\u9014\u4e2d\u306e\u6587\u5b57\u5217\u306e\u53d7\u3051\u6e21\u3057\u3092\u3059\u308b\u306a\u3089\u3001<span>StringBuilder<\/span>\u3092\u4f7f\u3046\u306e\u304c\u826f\u3044\u3067\u3057\u3087\u3046\u3002<\/p>\n<p>StringBuilder\u306b<span>String<\/span>\u3092\u8ffd\u52a0\u3059\u308b\u306b\u306f<span>append<\/span>\u3092\u3001\u5168\u90e8\u7e4b\u304c\u3063\u305f<span>String<\/span>\u3092\u5f97\u308b\u306b\u306f<span>toString<\/span>\u3092\u547c\u3073\u51fa\u3057\u307e\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">StringBuilder builder = new StringBuilder();\r\nbuilder.append(\"\u3042\u3044\u3046\u3048\u304a\").append(\"ABCD\");\r\nString str = builder.toString();\r\nSystem.out.println(str); \/\/ \u2192 \u3042\u3044\u3046\u3048\u304aABCD<\/pre>\n<p>StringBuilder.append\u306f\u3001<span>StringBuilder<\/span>\u81ea\u8eab\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u623b\u3057\u307e\u3059\u3002\u3067\u3059\u306e\u3067\u3053\u306e\u3088\u3046\u306b<span>append<\/span>\u3092\u3044\u304f\u3089\u3067\u3082\u7e4b\u3052\u3066\u547c\u3073\u51fa\u305b\u308b\u306e\u3067\u3059\u3002\u3053\u306e\u30b9\u30bf\u30a4\u30eb\u306f<span>Java<\/span>\u306e\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u3067\u306f\u3054\u304f\u666e\u901a\u306b\u898b\u3089\u308c\u307e\u3059\u306e\u3067\u3001\u6163\u308c\u3066\u304a\u304f\u3068\u3044\u3044\u3067\u3059\u3088<span>!<\/span><\/p>\n<pre class=\"prettyprint lang:default decode:true\">StringBuilder builder = new StringBuilder();\r\nfor (int i = 0; i &lt; 5; i++) {\r\n\tbuilder.append(\"\u3042\");\r\n}\r\nString str = builder.toString();\r\nSystem.out.println(str); \/\/ \u2192 \u3042\u3042\u3042\u3042\u3042<\/pre>\n<p>\u306a\u304a\u3001\u3053\u306e\u7528\u9014\u306b\u306f\u3001\u4ee5\u524d\u306f<span>StringBuffer<\/span>\u3092\u4f7f\u3063\u3066\u3044\u307e\u3057\u305f<span>(Java 1.4<\/span>\u4ee5\u524d<span>)<\/span>\u3002\u3067\u3059\u304c\u3001\u4eca\u3067\u306f\u307b\u3068\u3093\u3069\u306e\u30b1\u30fc\u30b9\u3067<span>StringBuilder<\/span>\u304c\u9069\u3057\u3066\u3044\u307e\u3059\u3002\u30de\u30eb\u30c1\u30b9\u30ec\u30c3\u30c9\u74b0\u5883\u3067\u7528\u3044\u308b\u306a\u3069\u306e\u7279\u6b8a\u30b1\u30fc\u30b9\u4ee5\u5916\u306f\u3001<span>StringBuilder<\/span>\u4e00\u629e\u3067\u3044\u3044\u3067\u3057\u3087\u3046\u3002<\/p>\n<h3><span id=\"-String-4\">\uff13-\uff15\uff0e\u6587\u5b57\u30b3\u30fc\u30c9\u3068<span>String<\/span><\/span><\/h3>\n<p>Java\u3067\u306f\u6587\u5b57\u5217\u3092\u3001<span>Unicode<\/span>\u306e<span>UTF-16<\/span>\u3068\u3044\u3046\u6587\u5b57\u30b3\u30fc\u30c9\u306e\u4ed5\u69d8\u306b\u5f93\u3063\u305f\u5f62\u5f0f\u3067\u3001\u5185\u90e8\u7684\u306b\u4fdd\u6301\u30fb\u5229\u7528\u3057\u3066\u3044\u307e\u3059\u3002\u305f\u3060\u3001<span>Java<\/span>\u3067\u30d7\u30ed\u30b0\u30e9\u30e0\u3092\u66f8\u3044\u3066\u3044\u308b\u969b\u306f\u305d\u308c\u3092\u6c17\u306b\u3059\u308b\u3053\u3068\u306f\u3042\u307e\u308a\u306a\u3044\u3068\u601d\u3044\u307e\u3059\u3002<\/p>\n<p>\u3044\u308f\u3086\u308b\u6587\u5b57\u30b3\u30fc\u30c9\u306f\u3001<span>Java<\/span>\u306e\u5916\u90e8\u304b\u3089\u30c7\u30fc\u30bf\u3092\u8aad\u307f\u8fbc\u3093\u3060\u6642\u3001<span>Java<\/span>\u304b\u3089\u5916\u90e8\u3078\u30c7\u30fc\u30bf\u3092\u66f8\u304d\u51fa\u3059\u6642\u306b\u610f\u8b58\u3059\u308b\u3053\u3068\u304c\u666e\u901a\u3067\u3057\u3087\u3046\u3002\u3082\u3061\u308d\u3093\u3001<span>Java<\/span>\u306e<span>String<\/span>\u306b\u306f\u3001\u305d\u306e\u3088\u3046\u306a\u8981\u6c42\u306b\u3082\u3070\u3063\u3061\u308a\u5fdc\u3048\u308b\u305f\u3081\u306e<span>API<\/span>\u304c\u3042\u308b\u306e\u3067\u3001\u3054\u5b89\u5fc3\u3092\u3002<\/p>\n<p>\u3053\u3053\u3067\u306f\u3001<span>String<\/span>\u3068\u6587\u5b57\u30b3\u30fc\u30c9\u306b\u3064\u3044\u3066\u5c11\u3057\u3060\u3051\u304a\u4f1d\u3048\u3057\u307e\u3059\u3002<\/p>\n<h4>\uff13-\uff15-\uff11\uff0e\u3053\u306e<span>String<\/span>\u306f\u4f55\u30d0\u30a4\u30c8<span>?<\/span><\/h4>\n<p>\u300c\u3053\u306e<span>String<\/span>\u306f\u4f55\u30d0\u30a4\u30c8<span>?<\/span>\u300d\u306b\u7b54\u3048\u308b\u306b\u306f\u3001\u300c\u3069\u306e\u30a8\u30f3\u30b3\u30fc\u30c7\u30a3\u30f3\u30b0\u306e\u5834\u5408\u3067\u3059\u304b<span>?<\/span>\u300d\u306e\u9006\u8cea\u554f\u306b\u307e\u305a\u7b54\u3048\u3066\u3082\u3089\u308f\u306a\u3051\u308c\u3070\u306a\u308a\u307e\u305b\u3093\u3002\u30a8\u30f3\u30b3\u30fc\u30c7\u30a3\u30f3\u30b0\u306b\u3088\u308a\u3001\u4e00\u6587\u5b57\u306e\u30d0\u30a4\u30c8\u6570\u304c\u9055\u3046\u304b\u3089\u3067\u3059\u3002<\/p>\n<p>\u30a8\u30f3\u30b3\u30fc\u30c7\u30a3\u30f3\u30b0\u3068\u306f\u3001\u5805\u82e6\u3057\u3044\u8a00\u8449\u3092\u4f7f\u3046\u3068\u300c\u6587\u5b57\u7b26\u53f7\u5316\u65b9\u5f0f<span>(character encoding scheme)<\/span>\u300d\u3068\u3044\u3046\u3082\u306e\u3067\u3001\u6587\u5b57\u3092\u6570\u5024\u3068\u3057\u3066\u8868\u73fe\u3059\u308b\u65b9\u6cd5\u306e\u3053\u3068\u3067\u3059\u3002\u65e5\u672c\u4eba\u30a8\u30f3\u30b8\u30cb\u30a2\u306b\u3068\u3063\u3066\u8eab\u8fd1\u306a\u3082\u306e\u3067\u306f\u3001<span>JIS<\/span>\u3001<span>Shift_JIS<\/span>\u3001<span>EUC-JP<\/span>\u3001<span>UTF-16<\/span>\u3001<span>UTF-8<\/span>\u306a\u3069\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n<p>String.getBytes\u3092\u30a8\u30f3\u30b3\u30fc\u30c7\u30a3\u30f3\u30b0\u3092\u6307\u5b9a\u3057\u3066\u547c\u3073\u51fa\u3059\u3068\u3001\u305d\u306e\u6587\u5b57\u5217\u306e\u30d0\u30a4\u30c8\u914d\u5217\u304c\u5f97\u3089\u308c\u307e\u3059\u3002\u30d0\u30a4\u30c8\u914d\u5217\u306e\u9577\u3055\u3092<span>length<\/span>\u3067\u8abf\u3079\u308c\u3070\u3001\u30d0\u30a4\u30c8\u6570\u304c\u5206\u304b\u308a\u307e\u3059\u3002\u30a8\u30f3\u30b3\u30fc\u30c7\u30a3\u30f3\u30b0\u306e\u6307\u5b9a\u306f\u4ee5\u4e0b\u306e\u4f8b\u306e\u3088\u3046\u306b<span>String<\/span>\u3067\u3082\u3044\u3044\u306e\u3067\u3059\u304c\u3001\u5c02\u7528\u306e\u30af\u30e9\u30b9<span>java.nio.charset.Charset<\/span>\u3092\u4f7f\u3063\u3066\u3082\u3044\u3044\u3067\u3057\u3087\u3046\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">String str = \"\u3042\";\r\n\r\nbyte[] utf32 = str.getBytes(\"UTF-32\"); \/\/ \u2192 [0x00 0x00 0x30 0x42]\r\nbyte[] utf16 = str.getBytes(\"UTF-16BE\"); \/\/ \u2192 [0x30 0x42]\r\nbyte[] utf8 = str.getBytes(\"UTF-8\"); \/\/ \u2192 [0xe3 0x81 0x82]\r\nbyte[] sjis = str.getBytes(\"Shift_JIS\"); \/\/ \u2192 [0x82 0xa0]\r\n\r\nSystem.out.println(utf32.length); \/\/ \u2192 4\u30d0\u30a4\u30c8(UTF-32)\r\nSystem.out.println(utf16.length); \/\/ \u2192 2\u30d0\u30a4\u30c8(UTF-16)\r\nSystem.out.println(utf8.length); \/\/ \u2192 3\u30d0\u30a4\u30c8(UTF-8)\r\nSystem.out.println(sjis.length); \/\/ \u2192 2\u30d0\u30a4\u30c8(Shift_JIS)<\/pre>\n<h4>\uff13-\uff15-\uff12\uff0e\u30d0\u30a4\u30ca\u30ea\u30c7\u30fc\u30bf\u304b\u3089<span>String<\/span>\u3092\u4f5c\u308b<\/h4>\n<p>\u6587\u5b57\u5217\u306e\u30d0\u30a4\u30ca\u30ea\u30c7\u30fc\u30bf\u304b\u3089<span>String<\/span>\u3092\u4f5c\u308b\u306b\u306f\u3001\u30d0\u30a4\u30c8\u914d\u5217\u3068\u30a8\u30f3\u30b3\u30fc\u30c7\u30a3\u30f3\u30b0\u3092\u6307\u5b9a\u3067\u304d\u308b<span>String<\/span>\u306e\u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf\u3092\u4f7f\u3044\u307e\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">byte[] utf32 = { 0x00, 0x00, 0x30, 0x42 }; \/\/ \u3042(UTF-32)\r\nbyte[] utf16 = { 0x30, 0x42 }; \/\/ \u3042(UTF-16BE)\r\nbyte[] utf8 = { (byte) 0xe3, (byte) 0x81, (byte) 0x82 }; \/\/ \u3042(UTF-8)\r\nbyte[] sjis = { (byte) 0x82, (byte) 0xa0 }; \/\/ \u3042(Shift_JIS)\r\n\r\nString strUtf32 = new String(utf32, \"UTF-32\"); \/\/ UTF-32\u306e\u30d0\u30a4\u30ca\u30ea\u30c7\u30fc\u30bf\u304b\u3089\u3001UTF-32\u306e\u30eb\u30fc\u30eb\u3067String\u3092\u4f5c\u308b\r\nString strUtf16 = new String(utf16, \"UTF-16BE\"); \/\/ UTF-16BE\u306e\u30d0\u30a4\u30ca\u30ea\u30c7\u30fc\u30bf\u304b\u3089\u3001UTF-16BE\u306e\u30eb\u30fc\u30eb\u3067String\u3092\u4f5c\u308b\r\nString strUtf8 = new String(utf8, \"UTF-8\"); \/\/ UTF-8\u306e\u30d0\u30a4\u30ca\u30ea\u30c7\u30fc\u30bf\u304b\u3089\u3001UTF-8\u306e\u30eb\u30fc\u30eb\u3067String\u3092\u4f5c\u308b\r\nString strSjis = new String(sjis, \"Shift_JIS\"); \/\/ Shift_JIS\u306e\u30d0\u30a4\u30ca\u30ea\u30c7\u30fc\u30bf\u304b\u3089\u3001Shift_JIS\u306e\u30eb\u30fc\u30eb\u3067String\u3092\u4f5c\u308b\r\n\r\nSystem.out.println(strUtf32); \/\/ \u2192 \u3042\r\nSystem.out.println(strUtf16); \/\/ \u2192 \u3042\r\nSystem.out.println(strUtf8); \/\/ \u2192 \u3042\r\nSystem.out.println(strSjis); \/\/ \u2192 \u3042<\/pre>\n<p>\u30d0\u30a4\u30ca\u30ea\u30c7\u30fc\u30bf\u306e\u30a8\u30f3\u30b3\u30fc\u30c7\u30a3\u30f3\u30b0\u3068\u3001<span>String<\/span>\u306e\u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf\u3067\u6307\u5b9a\u3059\u308b\u30a8\u30f3\u30b3\u30fc\u30c7\u30a3\u30f3\u30b0\u306f\u540c\u3058\u3067\u306a\u3044\u3068\u3044\u3051\u307e\u305b\u3093\u3002\u540c\u3058\u3067\u306a\u3051\u308c\u3070\u3001<span>Java<\/span>\u304c\u30d0\u30a4\u30ca\u30ea\u30c7\u30fc\u30bf\u3092\u3069\u3046\u3084\u3063\u3066<span>String<\/span>\u306b\u5909\u63db\u3059\u308c\u3070\u3044\u3044\u306e\u304b\u308f\u304b\u3089\u305a\u3001\u6587\u5b57\u5316\u3051\u3059\u308b\u304b<span>&#8220;?&#8221;<\/span>\u306b\u306a\u3063\u3066\u3057\u307e\u3044\u307e\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">String str = \"\u3042\";\r\nbyte[] utf16 = str.getBytes(\"UTF-16BE\"); \/\/ String\u3092UTF-16\u306e\u30d0\u30a4\u30ca\u30ea\u30c7\u30fc\u30bf\u306b\u5909\u63db\u3057\u3066\u3001\r\nString strUtf8 = new String(utf16, \"UTF-8\"); \/\/ UTF-16\u306e\u30d0\u30a4\u30ca\u30ea\u30c7\u30fc\u30bf\u3092UTF-8\u3067\u89e3\u91c8\u3059\u308b\u3068\u3001\r\nSystem.out.println(strUtf8); \/\/ \u2192 0B\u3001\"\u3042\"\u306b\u306f\u306a\u3089\u306a\u3044<\/pre>\n<p>\u30d0\u30a4\u30ca\u30ea\u30c7\u30fc\u30bf\u304b\u3089\u6587\u5b57\u5217\u306e\u30a8\u30f3\u30b3\u30fc\u30c7\u30a3\u30f3\u30b0\u3092\u76f4\u63a5\u5224\u5225\u3059\u308b\u306e\u306f\u3001\u6b8b\u5ff5\u306a\u304c\u3089\u7c21\u5358\u3067\u306f\u3042\u308a\u307e\u305b\u3093\u3002\u3067\u3059\u306e\u3067\u3001\u666e\u901a\u306f\u30d7\u30ed\u30b0\u30e9\u30e0\u3092\u4f5c\u308b\u6642\u306b\u4e8b\u524d\u306b\u53d6\u308a\u6c7a\u3081\u308b\u3053\u3068\u306b\u306a\u308a\u307e\u3059\u3002\u3042\u308b\u3044\u306f\u3001<span>HTTP<\/span>\u306a\u3069\u306e\u901a\u4fe1\u30d7\u30ed\u30c8\u30b3\u30eb\u306e\u3088\u3046\u306b\u3001\u30c7\u30fc\u30bf\u901a\u4fe1\u6642\u306b\u30a8\u30f3\u30b3\u30fc\u30c7\u30a3\u30f3\u30b0\u306f\u4f55\u304b\u3001\u90fd\u5ea6\u76f8\u624b\u304b\u3089\u6559\u3048\u3066\u3082\u3089\u3046\u304b\u3067\u3059\u3002<\/p>\n<h2><span id=\"StringJava_811\">\uff14\uff0e\u3010\u4fbf\u5229\u3011\u3053\u3053\u6700\u8fd1\u306e<span>String<\/span>\u4e8b\u60c5<span>(Java 8<\/span>\uff5e<span>11)<\/span><\/span><\/h2>\n<p>\u3055\u3066\u3001\u3053\u3053\u307e\u3067\u3067<span>String<\/span>\u3067\u305c\u3072\u77e5\u3063\u3066\u3044\u305f\u3060\u304d\u305f\u3044\u3053\u3068\u3092\u304a\u4f1d\u3048\u3057\u3066\u304d\u307e\u3057\u305f\u3002<\/p>\n<p>String\u306f<span>Java<\/span>\u306e\u4ed5\u7d44\u307f\u3092\u6839\u5e95\u304b\u3089\u652f\u3048\u308b\u5927\u5909\u5927\u4e8b\u306a\u30af\u30e9\u30b9\u3067\u3059\u304c\u3001\u6539\u826f\u304c\u6b62\u307e\u3063\u3066\u3044\u308b\u308f\u3051\u3067\u306f\u3042\u308a\u307e\u305b\u3093\u3002\u6700\u8fd1\u3082\u3044\u304f\u3064\u304b\u306e\u30e1\u30bd\u30c3\u30c9\u304c\u8ffd\u52a0\u3055\u308c\u3066\u3001\u3088\u308a\u304b\u3086\u3044\u3068\u3053\u308d\u306b\u624b\u304c\u5c4a\u304f\u3088\u3046\u306b\u306a\u3063\u3066\u3044\u307e\u3059\u3002<\/p>\n<p>\u3053\u3053\u3067\u306f\u3001<span>Java 8<\/span>\u4ee5\u964d\u3067\u8ffd\u52a0\u3055\u308c\u305f<span>String<\/span>\u306e\u4fbf\u5229\u306a\u30e1\u30bd\u30c3\u30c9\u305f\u3061\u3092\u7d39\u4ecb\u3057\u307e\u3059\u3002\u3068\u3066\u3082\u4f7f\u3044\u52dd\u624b\u306e\u826f\u3044\u3082\u306e\u304c\u63c3\u3063\u3066\u3044\u307e\u3059\u3088\u3002<\/p>\n<h3><span id=\"-StringjoinJava_8\">\uff14-\uff11\uff0eString\u3092\u7e4b\u3052\u308b<span>join<\/span>\u3010<span>Java 8<\/span>\uff5e\u3011<\/span><\/h3>\n<p>\u3044\u304f\u3064\u304b\u306e<span>String<\/span>\u3092\u4f55\u304b\u306e\u6587\u5b57\u5217\u3067\u7e4b\u3052\u3066\u3088\u308a\u5927\u304d\u306a\u5225\u306e\u6587\u5b57\u5217\u3092\u4f5c\u308b\u3053\u3068\u306f\u3001\u30d7\u30ed\u30b0\u30e9\u30e0\u3067\u306f\u983b\u7e41\u306b\u884c\u3044\u307e\u3059\u3002\u4f8b\u3048\u3070\u3001<span>String<\/span>\u306e<span>List<\/span>\u3092<span>&#8220;,&#8221;<\/span>\u3067\u7e4b\u3052\u3066\u3001<span>CSV(Comma-Separated Values)<\/span>\u306b\u3059\u308b\u3068\u304b\u3067\u3059\u306d\u3002<\/p>\n<p>\u3067\u3082\u3001\u4ee5\u524d\u306e<span>Java<\/span>\u306e\u6a19\u6e96<span>API<\/span>\u3067\u306f\u3001\u305d\u3093\u306a\u7e4b\u3052\u308b\u51e6\u7406\u304c\u7c21\u5358\u306b\u3067\u304d\u307e\u305b\u3093\u3067\u3057\u305f\u3002\u3067\u3059\u306e\u3067\u3001<span>for<\/span>\u6587\u3068<span>StringBuilder<\/span>\u306a\u3069\u3092\u4f7f\u3063\u3066\u7e4b\u3052\u308b\u30e1\u30bd\u30c3\u30c9\u3092\u81ea\u5206\u3067\u4f5c\u3063\u305f\u3082\u306e\u3067\u3059\u3002<\/p>\n<p>Java 8\u3067\u306f\u3001\u5f85\u671b\u306e<span>String.join<\/span>\u304c\u8ffd\u52a0\u3055\u308c\u307e\u3057\u305f\u3002\u4f7f\u3044\u65b9\u306f\u8d85\u7c21\u5358\u3001\u8d85\u76f4\u611f\u7684\u3067\u3059\u3002\u3061\u306a\u307f\u306b\u3001\u533a\u5207\u308a\u6587\u5b57\u304c\u3044\u3089\u306a\u3044\u306a\u3089<span>&#8220;&#8221;<\/span>\u306b\u3059\u308c\u3070\u3044\u3044\u3060\u3051\u3067\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">String str = String.join(\",\", \"\u3042\", \"\u3044\", \"\u3046\", \"\u3048\", \"\u304a\");\r\nSystem.out.println(str); \/\/ \u2192 \"\u3042,\u3044,\u3046,\u3048,\u304a\"<\/pre>\n<pre class=\"prettyprint lang:default decode:true\">String[] array = {\"\u3042\", \"\u3044\", \"\u3046\", \"\u3048\", \"\u304a\"};\r\nString str = String.join(\",\", array);\r\nSystem.out.println(str); \/\/ \u2192 \"\u3042,\u3044,\u3046,\u3048,\u304a\"<\/pre>\n<pre class=\"prettyprint lang:default decode:true\">List&lt;String&gt; list = Arrays.asList(\"\u3042\", \"\u3044\", \"\u3046\", \"\u3048\", \"\u304a\");\r\nString str = String.join(\",\", list);\r\nSystem.out.println(str); \/\/ \u2192 \"\u3042,\u3044,\u3046,\u3048,\u304a\"<\/pre>\n<h4>\uff14-\uff11-\uff11\uff0eStringJoiner\u306e\u4f7f\u3044\u65b9<\/h4>\n<p>String.join\u3060\u3068\u3001\u9593\u306b\u631f\u307f\u8fbc\u3093\u3067\u4f55\u304b\u3092\u7e4b\u3052\u308b\u3060\u3051\u3067\u3059\u3002\u52d5\u7684\u306b\u30d7\u30ed\u30b0\u30e9\u30e0\u3092\u3059\u308b\u5fc5\u8981\u304c\u3042\u308b\u306a\u3089\u3001<span>java.util.StringJoiner<\/span>\u3092\u4f7f\u3063\u3066\u307f\u3066\u3082\u3044\u3044\u3067\u3057\u3087\u3046\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">StringJoiner joiner = new StringJoiner(\",\");\r\njoiner.add(\"\u3042\");\r\njoiner.add(\"\u3044\");\r\njoiner.add(\"\u3046\");\r\nString str = joiner.toString();\r\nSystem.out.println(str); \/\/ \u2192 \"\u3042,\u3044,\u3046\"<\/pre>\n<p>StringBuilder\u3092\u4f7f\u3046\u5834\u5408\u306b\u6bd4\u3079\u308b\u3068\u3001<span>&#8220;,&#8221;<\/span>\u3092\u631f\u307f\u8fbc\u3080\u51e6\u7406<span>(<\/span>\u6761\u4ef6\u3092\u8003\u3048\u308b\u3068\u7d50\u69cb\u9762\u5012\u304f\u3055\u3044<span>!!)<\/span>\u3092\u66f8\u304b\u306a\u304f\u3066\u3082\u3044\u3044\u306e\u3067\u3001\u305d\u308c\u3060\u3051\u3067\u3082\u697d\u3067\u3059\u306d\u3002<\/p>\n<p>\u7e4b\u3052\u305f\u6587\u5b57\u5217\u306e\u524d\u5f8c\u306b\u6587\u5b57\u5217\u3092\u8ffd\u52a0\u3057\u305f\u3044\u5834\u5408\u3082\u7c21\u5358\u3067\u3001<span>StringJoiner<\/span>\u306e\u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf\u3067\u305d\u308c\u305e\u308c\u6307\u5b9a\u3059\u308c\u3070\u3044\u3044\u3060\u3051\u3067\u3059\u3002\u3053\u308c\u3067\u30d7\u30ed\u30b0\u30e9\u30e0\u30df\u30b9\u304c\u6e1b\u3089\u305b\u305d\u3046\u3067\u3059\u306d\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">StringJoiner joiner = new StringJoiner(\"],[\", \"[\", \"]\");\r\njoiner.add(\"\u3042\");\r\njoiner.add(\"\u3044\");\r\njoiner.add(\"\u3046\");\r\nString str = joiner.toString();\r\nSystem.out.println(str); \/\/ \u2192 \"[\u3042],[\u3044],[\u3046]\"<\/pre>\n<h3><span id=\"-StreamcharsJava_9\">\uff14-\uff12\uff0e\u6587\u5b57\u306e<span>Stream<\/span>\u3092\u53d6\u5f97\u3059\u308b<span>chars<\/span>\u3010<span>Java 9<\/span>\uff5e\u3011<\/span><\/h3>\n<p>String\u304c\u6301\u3063\u3066\u3044\u308b\u6587\u5b57\u5358\u4f4d\u3067\u4f55\u304b\u51e6\u7406\u3092\u3057\u305f\u3044\u3001\u305d\u3046\u3044\u3046\u5834\u5408\u306b\u6587\u5b57\u3092<span>IntStream<\/span>\u3068\u3057\u3066\u53d6\u5f97\u3067\u304d\u308b\u30e1\u30bd\u30c3\u30c9<span>chars<\/span>\u304c\u3001<span>Java 9<\/span>\u3067\u8ffd\u52a0\u3055\u308c\u307e\u3057\u305f\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">String str = \"\u3042\u3044\u3046\u3048\u304a\";\r\nstr.chars().forEach(i -&gt; System.out.println((char) i));<\/pre>\n<h4>\uff14-\uff12-\uff11\uff0e\u3010\u767a\u5c55\u3011\u30b3\u30fc\u30c9\u30dd\u30a4\u30f3\u30c8\u306e<span>Stream<\/span>\u3092\u53d6\u5f97\u3059\u308b<span>codePoints<\/span>\u3010<span>Java 9<\/span>\uff5e\u3011<\/h4>\n<p>String.chars\u306f\u3001\u3042\u304f\u307e\u3067<span>char<\/span>\u5358\u4f4d\u3067\u306e<span>Stream<\/span>\u3067\u3059\u3002\u305d\u306e\u305f\u3081\u3001\u30b5\u30ed\u30b2\u30fc\u30c8\u30da\u30a2\u3067\u8868\u73fe\u3055\u308c\u308b\u7bc4\u56f2\u306e\u6587\u5b57\u3082\u3001\u4e0a\u4f4d\u30b5\u30ed\u30b2\u30fc\u30c8\u3068\u4e0b\u4f4d\u30b5\u30ed\u30b2\u30fc\u30c8\u306f\u72ec\u7acb\u3057\u305f\u6587\u5b57\u3068\u3057\u3066\u6271\u3044\u307e\u3059\u3002<\/p>\n<p>\u30b5\u30ed\u30b2\u30fc\u30c8\u30da\u30a2\u306e\u7bc4\u56f2\u306e\u6587\u5b57\u3082\u4e00\u3064\u306e\u6587\u5b57\u306e\u30b3\u30fc\u30c9\u30dd\u30a4\u30f3\u30c8\u3068\u3057\u3066<span>Stream<\/span>\u3067\u6271\u3044\u305f\u3044\u306a\u3089\u3001\u540c\u3058\u304f<span>Java 9<\/span>\u3067\u8ffd\u52a0\u3055\u308c\u305f<span>String.codePoints<\/span>\u3092\u4f7f\u3044\u307e\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">String str = \"?\u91ce\u5c4b\"; \/\/ \u6700\u521d\u306e\u6587\u5b57\u306f\u3044\u308f\u3086\u308b\u300c\u3064\u3061\u3088\u3057\u300d\u3001Unicode\u3067\u306f\u30b5\u30ed\u30b2\u30fc\u30c8\u30da\u30a2\u306e\u7bc4\u56f2\u306e\u6587\u5b57\r\nstr.codePoints().forEach(i -&gt; System.out.println(i)); \/\/ 3\u56deprint\u3055\u308c\u308b\u306e\u3067\u3001\u30b5\u30ed\u30b2\u30fc\u30c8\u30da\u30a2\u3092\u6b63\u3057\u304f\u8a8d\u8b58\u3067\u304d\u3066\u3044\u308b<\/pre>\n<h3><span id=\"-Java_9String\">\uff14-\uff13\uff0e\u3010\u767a\u5c55\u3011<span>Java 9<\/span>\u3067\u306e<span>String<\/span>\u95a2\u9023\u5909\u66f4<\/span><\/h3>\n<p>Java 9\u3067\u306f<span>String<\/span>\u95a2\u9023\u306e\u5909\u66f4\u304c\u3044\u304f\u3064\u304b\u3042\u308a\u307e\u3057\u305f\u3002\u4ee5\u4e0b\u306e\u5916\u306b\u3082\u3042\u308a\u307e\u3059\u304c\u3001<span>String<\/span>\u3092\u4f7f\u3063\u305f\u30d7\u30ed\u30b0\u30e9\u30e0\u306b\u306f\u76f4\u63a5\u7684\u306a\u95a2\u4fc2\u306f\u306a\u3044\u306e\u3067\u3001\u8aac\u660e\u306f\u7701\u304d\u307e\u3059\u3002<\/p>\n<p>String\u306e<span>API<\/span>\u3068\u3057\u3066\u306f\u5909\u66f4\u306f\u306a\u3044\u306e\u3067\u4f7f\u3044\u52dd\u624b\u306f\u305d\u306e\u307e\u307e\u3067\u3059\u3002\u3067\u3082<span>Java 9<\/span>\u4ee5\u964d\u306b\u5207\u308a\u66ff\u3048\u308c\u3070\u3001\u3082\u3057\u304b\u3059\u308b\u3068\u5c11\u3057\u306f\u30e1\u30e2\u30ea\u4f7f\u7528\u91cf\u304c\u6e1b\u3063\u305f\u308a\u3001\u5b9f\u884c\u901f\u5ea6\u304c\u901f\u304f\u306a\u308b\u304b\u3082\u3057\u308c\u307e\u305b\u3093\u306d\u3002<\/p>\n<h4>\uff14-\uff13-\uff11\uff0eString\u306e\u5185\u90e8\u4fdd\u6301\u30c7\u30fc\u30bf\u5f62\u5f0f\u306e\u5909\u66f4\u3010<span>Java 9<\/span>\uff5e\u3011<\/h4>\n<p>String\u306f\u3001<span>Java 8<\/span>\u307e\u3067\u306f\u5185\u90e8\u3067\u3082<span>char<\/span>\u306e\u914d\u5217\u3067\u6587\u5b57\u5217\u3092\u4fdd\u6301\u3057\u3066\u3044\u307e\u3057\u305f\u3002<span>Java<\/span>\u3067\u306e\u4e00\u6587\u5b57\u3067\u3042\u308b<span>char<\/span>\u306f<span>2<\/span>\u30d0\u30a4\u30c8<span>(16<\/span>\u30d3\u30c3\u30c8<span>)<\/span>\u3067\u3059\u304c\u3001\u3044\u308f\u3086\u308b\u534a\u89d2\u82f1\u6570\u5b57\u306e\u7bc4\u56f2\u3060\u3051\u306a\u3089\u4e00\u6587\u5b57\u306f<span>1<\/span>\u30d0\u30a4\u30c8<span>(8<\/span>\u30d3\u30c3\u30c8<span>)<\/span>\u3067\u8db3\u308a\u308b\u306e\u3067\u3001\u30e1\u30e2\u30ea\u304c\u7121\u99c4\u306b\u4f7f\u308f\u308c\u3066\u3044\u308b\u3068\u307f\u306a\u3055\u308c\u3066\u3044\u307e\u3057\u305f\u3002\u3053\u308c\u306f\u6b27\u7c73\u570f\u306e\u30d7\u30ed\u30b0\u30e9\u30e0\u3067\u306f\u554f\u984c\u3060\u3063\u305f\u3088\u3046\u3067\u3059\u3002<\/p>\n<p>Java 9\u3067\u306e\u300c<span>JEP 254: Compact Strings<\/span>\u300d\u306b\u3066\u3001<span>String<\/span>\u5185\u90e8\u306e\u30c7\u30fc\u30bf\u4fdd\u6301\u65b9\u6cd5\u304c<span>byte<\/span>\u914d\u5217\u306b\u5909\u66f4\u3055\u308c\u307e\u3057\u305f\u3002<span>byte<\/span>\u914d\u5217\u306b\u306a\u3063\u305f\u3053\u3068\u3067\u3001<span>String<\/span>\u304c\u6301\u3064\u6587\u5b57\u5217\u304c\u4e00\u6587\u5b57<span>1<\/span>\u30d0\u30a4\u30c8\u306e\u7bc4\u56f2\u3060\u3051\u3067\u3042\u308b\u5834\u5408\u3068\u3001\u4e00\u6587\u5b57\u306b\u30de\u30eb\u30c1\u30d0\u30a4\u30c8\u304c\u5fc5\u8981\u306a\u7bc4\u56f2\u3067\u3042\u308b\u5834\u5408\u3068\u3067\u3001\u30c7\u30fc\u30bf\u306e\u6301\u3061\u65b9\u304c\u67d4\u8edf\u306b\u5909\u3048\u3089\u308c\u308b\u3088\u3046\u306b\u306a\u3063\u305f\u306e\u3067\u3059\u3002<\/p>\n<h4>\uff14-\uff13-\uff12\uff0eString\u3092<span>+<\/span>\u3059\u308b\u6642\u306e\u51e6\u7406\u65b9\u5f0f\u306e\u5909\u66f4\u3010<span>Java 9<\/span>\uff5e\u3011<\/h4>\n<p>String\u3092<span>+<\/span>\u3057\u305f\u6642\u306f\u3001<span>Java 8<\/span>\u4ee5\u524d\u3067\u306f<span>StringBuilder.append<\/span>\u3092\u4f7f\u3063\u3066\u6587\u5b57\u5217\u3092\u7e4b\u3052\u308b\u3088\u3046\u3001\u30d7\u30ed\u30b0\u30e9\u30e0\u306e\u8aad\u307f\u66ff\u3048\u304c\u30b3\u30f3\u30d1\u30a4\u30eb\u6642\u306b\u884c\u308f\u308c\u3066\u3044\u307e\u3057\u305f\u3002<\/p>\n<p>Java 9\u304b\u3089\u306f\u3001<span>+<\/span>\u306e\u5177\u4f53\u7684\u306a\u51e6\u7406\u5185\u5bb9\u3092<span>Java<\/span>\u304c\u5b9f\u884c\u6642\u306b\u6c7a\u5b9a\u3067\u304d\u308b\u3088\u3046\u306b\u306a\u308a\u307e\u3057\u305f<span>(JEP 280: Indify String Concatenation)<\/span>\u3002\u5909\u66f4\u306e\u7406\u7531\u306f\u3001\u6587\u5b57\u5217\u9023\u7d50\u51e6\u7406\u306b\u6027\u80fd\u6539\u5584\u306e\u4f59\u5730\u3092\u4f5c\u308b\u305f\u3081\u3067\u3059\u3002\u6587\u5b57\u5217\u9023\u7d50\u304c<span>StringBuilder<\/span>\u306b\u4f9d\u5b58\u3057\u3066\u3044\u3066\u306f\u3001\u3082\u3063\u3068\u3044\u3044\u3084\u308a\u65b9\u304c\u3042\u3063\u305f\u3068\u3057\u3066\u3082\u6027\u80fd\u6539\u5584\u304c\u51fa\u6765\u306a\u3044\u306e\u3067\u3059\u3002<\/p>\n<p>\u4f8b\u3048\u3070\u73fe\u5728\u306e\u5b9f\u88c5\u306e\u4e00\u3064\u306f\u3001\u6587\u5b57\u5217\u9023\u7d50\u306b\u5fc5\u8981\u306a\u9577\u3055\u306e<span>byte<\/span>\u914d\u5217\u3092\u52d5\u7684\u306b\u7528\u610f\u3057\u3001\u305d\u3053\u306b\u6587\u5b57\u5217\u3092\u30b3\u30d4\u30fc\u3057\u3066\u65b0\u3057\u3044<span>String<\/span>\u3092\u4f5c\u308b\u3001\u3068\u3044\u3046\u3082\u306e\u306e\u3088\u3046\u3067\u3059\u3002\u3067\u3082\u3001\u3082\u3063\u3068\u3044\u3044\u65b9\u6cd5\u304c\u5b9f\u88c5\u3055\u308c\u308c\u3070\u3001\u3053\u308c\u304b\u3089\u306f<span>Java<\/span>\u306e\u5b9f\u884c\u74b0\u5883\u3092\u5909\u66f4\u3059\u308b\u3060\u3051\u3067\u6027\u80fd\u304c\u30a2\u30c3\u30d7\u3059\u308b\u53ef\u80fd\u6027\u304c\u3042\u308b\u306e\u3067\u3059\u3002<\/p>\n<h3><span id=\"-linesJava_11\">\uff14-\uff14\uff0e\u6539\u884c\u30b3\u30fc\u30c9\u3067\u5206\u5272\u3059\u308b<span>lines<\/span>\u3010<span>Java 11<\/span>\uff5e\u3011<\/span><\/h3>\n<p>String.split\u306e\u7279\u6b8a\u5f62\u3068\u3057\u3066\u3001\u6539\u884c\u30b3\u30fc\u30c9\u3067\u5206\u5272\u3059\u308b\u3082\u306e\u304c<span>Java 9<\/span>\u3067\u8ffd\u52a0\u3055\u308c\u307e\u3057\u305f\u3002\u306a\u304b\u306a\u304b\u512a\u308c\u3082\u306e\u3067\u3001\u6539\u884c\u30b3\u30fc\u30c9\u306e\u7a2e\u985e\u3082\u3061\u3083\u3093\u3068\u898b\u3066\u304f\u308c\u307e\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">String str = \"\u3042\\r\u3044\\n\u3046\\r\\n\u3048\\n\u304a\";\r\nstr.lines().forEach(System.out::println);<\/pre>\n<h3><span id=\"-isBlankJava_11\">\uff14-\uff15\uff0e\u7a7a\u767d\u3057\u304b\u306a\u3044\u304b\u3092\u78ba\u8a8d\u3059\u308b<span>isBlank<\/span>\u3010<span>Java 11<\/span>\uff5e\u3011<\/span><\/h3>\n<p>Java 11\u304b\u3089\u306e<span>String.isBlank<\/span>\u3092\u4f7f\u3046\u3068\u3001\u6587\u5b57\u5217\u304c\u7a7a\u767d\u3060\u3051\u304b\u3089\u306a\u308b\u3082\u306e\u304b\u8abf\u3079\u3066\u304f\u308c\u307e\u3059\u3002<span>isBlank<\/span>\u306e\u3044\u3044\u3068\u3053\u308d\u306f\u3001\u3044\u308f\u3086\u308b\u5168\u89d2\u7a7a\u767d\u3082\u7a7a\u767d\u3068\u3057\u3066\u30c1\u30a7\u30c3\u30af\u3057\u3066\u304f\u308c\u308b\u3053\u3068\u3067\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">String str = \" \u3000\\t\\r\\n\"; \/\/ \u5168\u89d2\u7a7a\u767d\u304c\u6df7\u3056\u3063\u3066\u3044\u307e\u3059\r\nboolean blank = str.isBlank();\r\nSystem.out.println(blank); \/\/ \u2192 true<\/pre>\n<p>\u3067\u306f\u3053\u3053\u3067\u8a00\u3046\u7a7a\u767d\u3068\u306f\u4f55\u304b\u3001\u304c\u5927\u4e8b\u306a\u3068\u3053\u308d\u3067\u3059\u3002\u53b3\u5bc6\u306b\u306f\u3001<span>Unicode<\/span>\u3067\u7a7a\u767d\u3067\u3042\u308b\u3068\u30b0\u30eb\u30fc\u30d7\u5316\u3055\u308c\u3066\u3044\u308b\u6587\u5b57\u7fa4\u3068\u305d\u306e\u4ed6\u3044\u304f\u3064\u304b\u306b\u306a\u308a\u307e\u3059\u3002\u305d\u306e\u4e2d\u306b\u5168\u89d2\u7a7a\u767d\u3082\u5165\u3063\u3066\u3044\u308b\u3068\u3044\u3046\u3053\u3068\u3067\u3059\u306d\u3002\u611f\u899a\u7684\u306b\u7a7a\u767d\u6271\u3044\u3057\u305f\u3044\u6587\u5b57\u306f\u3001\u5927\u4f53\u5165\u3063\u3066\u3044\u308b\u3068\u601d\u3044\u307e\u3059\u3002<\/p>\n<p>\u8a73\u3057\u304f\u306f\u3001<span>Character.isWhitespace<\/span>\u306e<span>Javadoc<\/span>\u3092\u53c2\u7167\u3057\u3066\u304f\u3060\u3055\u3044\u3002<\/p>\n<h3><span id=\"-stripstripLeadingstripTrailingJava_11\">\uff14-\uff16\uff0e\u5168\u89d2\u7a7a\u767d\u3082\u524a\u9664\u3059\u308b<span>strip\/stripLeading\/stripTrailing<\/span>\u3010<span>Java 11<\/span>\uff5e\u3011<\/span><\/h3>\n<p>\u30d7\u30ed\u30b0\u30e9\u30e0\u3067\u3088\u304f\u3042\u308b\u306e\u304c\u3001<span>String<\/span>\u306e\u524d\u5f8c\u306b\u3042\u308b\u4f59\u8a08\u306a\u7a7a\u767d<span>(<\/span>\u6271\u3044\u3057\u305f\u3044\u6587\u5b57<span>)<\/span>\u3092\u524a\u9664\u3059\u308b\u3053\u3068\u3067\u3059\u3002<\/p>\n<p>\u666e\u901a\u306f<span>String.trim<\/span>\u3092\u4f7f\u3046\u306e\u3067\u3059\u304c\u3001\u6b8b\u5ff5\u306a\u304c\u3089<span>trim<\/span>\u3057\u3066\u304f\u308c\u308b\u6587\u5b57\u306f\u304b\u306a\u308a\u5236\u9650\u3055\u308c\u3066\u3044\u307e\u3059\u3002\u4f8b\u3048\u3070\u3001\u65e5\u672c\u8a9e\u74b0\u5883\u3067\u306f\u5168\u89d2\u7a7a\u767d\u3082\u524a\u9664\u3057\u305f\u3044\u306e\u306b<span>trim<\/span>\u3067\u306f\u3057\u3066\u304f\u308c\u306a\u3044\u306e\u3067\u3001\u4ed5\u65b9\u306a\u304f\u81ea\u5206\u3067<span>String.substring<\/span>\u3092\u4f7f\u3063\u3066\u51e6\u7406\u3092\u4f5c\u3063\u305f<span>\u2026<\/span>\u3068\u3044\u3046\u65b9\u3082\u591a\u3044\u3067\u3057\u3087\u3046\u3002<\/p>\n<p>\u305d\u3093\u306a\u4eba\u3078\u306e\u304a\u52e7\u3081\u304c<span>String.strip<\/span>\u3067\u3059\u3002\u4ef2\u9593\u3068\u3057\u3066<span>stripLeading\/stripTrailing<\/span>\u3082\u3042\u308a\u307e\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">String str = \" \u3000 \u3042\u3044\u3046\u3048\u304a \u3000 \"; \/\/ \u524d\u5f8c\u306b\u5168\u89d2\u7a7a\u767d\u304c\u6df7\u3056\u3063\u3066\u3044\u307e\u3059\r\nString stripped1 = str.strip();\r\nString stripped2 = str.stripLeading();\r\nString stripped3 = str.stripTrailing();\r\nSystem.out.println(stripped1); \/\/ \u2192 \"\u3042\u3044\u3046\u3048\u304a\"\r\nSystem.out.println(stripped2); \/\/ \u2192 \"\u3042\u3044\u3046\u3048\u304a \u3000 \"\r\nSystem.out.println(stripped3); \/\/ \u2192 \" \u3000 \u3042\u3044\u3046\u3048\u304a\"<\/pre>\n<p>\u524a\u9664\u3055\u308c\u308b\u6587\u5b57\u306f\u3001<span>isBlank<\/span>\u3068\u540c\u69d8\u306b<span>Character.isWhitespace<\/span>\u304c<span>true<\/span>\u3092\u623b\u3059\u6587\u5b57\u3067\u3059\u3002\u8a73\u7d30\u306f<span>Javadoc<\/span>\u3092\u53c2\u7167\u3057\u3066\u304f\u3060\u3055\u3044\u3002<\/p>\n<h3><span id=\"-StringrepeatJava_11\">\uff14-\uff17\uff0eString\u3092\u7e70\u308a\u8fd4\u3059<span>repeat<\/span>\u3010<span>Java 11<\/span>\uff5e\u3011<\/span><\/h3>\n<p>\u540c\u3058\u6587\u5b57\u5217\u3092\u7e70\u308a\u8fd4\u3057\u305f\u3044\u6642\u3001<span>for<\/span>\u6587\u3092\u305d\u306e\u56de\u6570\u3060\u3051\u4f7f\u3063\u3066\u6587\u5b57\u5217\u3092\u9023\u7d50\u3059\u308b\u306e\u304c\u666e\u901a\u3060\u3068\u601d\u3044\u307e\u3059\u3002<span>Java 11<\/span>\u3067\u306f\u3001\u305d\u306e\u305f\u3081\u306b\u4f7f\u3048\u308b<span>String.repeat<\/span>\u304c\u8ffd\u52a0\u3055\u308c\u307e\u3057\u305f\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">String str = \"\u3042\u3044\u3046\u3048\u304a\";\r\nString repeated = str.repeat(3);\r\nSystem.out.println(repeated); \/\/ \u2192 \"\u3042\u3044\u3046\u3048\u304a\u3042\u3044\u3046\u3048\u304a\u3042\u3044\u3046\u3048\u304a\"<\/pre>\n<h2><span id=\"i-5\">\uff15\uff0e\u3055\u3044\u3054\u306b<\/span><\/h2>\n<p>\u3053\u306e\u8a18\u4e8b\u3067\u306f\u3001<span>Java<\/span>\u306e<span>String<\/span>\u306e\u57fa\u672c\u3068\u767a\u5c55\u306b\u95a2\u3059\u308b\u77e5\u8b58\u3001<span>Java 8<\/span>\uff5e<span>11<\/span>\u307e\u3067\u306e\u4e3b\u306a\u5909\u66f4\u70b9\u3092\u304a\u4f1d\u3048\u3057\u307e\u3057\u305f\u3002<\/p>\n<p>Java\u306b\u9650\u3089\u305a\u3001\u6587\u5b57\u5217\u306f\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u306b\u304a\u3051\u308b\u57fa\u672c\u7684\u306a\u30c7\u30fc\u30bf\u69cb\u9020\u306e\u4e00\u3064\u3067\u3059\u3002\u305d\u3057\u3066\u3001\u30e1\u30fc\u30eb\u3082\u3001\u30c1\u30e3\u30c3\u30c8\u3082\u3001\u3053\u306e\u8a18\u4e8b\u3082\u3001<span>HTML<\/span>\u3082<span>XML<\/span>\u3082<span>JSON<\/span>\u3082\u5168\u3066\u6587\u5b57\u5217\u3067\u3059\u3002<span>HTTP<\/span>\u306a\u3069\u306e\u30cd\u30c3\u30c8\u30ef\u30fc\u30af\u30d7\u30ed\u30c8\u30b3\u30eb\u3067\u306f\u3001\u30b5\u30fc\u30d0\u9593\u306e\u3084\u308a\u3068\u308a\u306f\u6587\u5b57\u5217\u3067\u3059\u3002\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u3078\u3082\u6587\u5b57\u5217\u3067\u60c5\u5831\u3092\u4fdd\u5b58\u3057\u3001\u53d6\u308a\u51fa\u305b\u305f\u308a\u3057\u307e\u3059\u3002<\/p>\n<p>\u3067\u3059\u304b\u3089\u3001\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u306e\u4e00\u3064\u306e\u5074\u9762\u306f\u3001\u30d7\u30ed\u30b0\u30e9\u30e0\u4e0a\u3067\u6587\u5b57\u5217\u3092\u3069\u3046\u4f5c\u308a\u8fbc\u3080\u304b\u3001\u30d7\u30ed\u30b0\u30e9\u30e0\u306e\u5916\u90e8\u304b\u3089\u4e0e\u3048\u3089\u308c\u305f\u6587\u5b57\u5217\u3092\u3069\u3046\u89e3\u91c8\u3059\u308b\u304b\u3001\u6587\u5b57\u5217\u3092\u3069\u3046\u52a0\u5de5\u3059\u308c\u3070\u610f\u5473\u306e\u3042\u308b\u3082\u306e\u306b\u52b9\u7387\u7684\u306b\u5909\u63db\u3067\u304d\u308b\u304b<span>\u2026<\/span>\u3067\u3042\u308b\u3068\u3082\u8a00\u3048\u308b\u3067\u3057\u3087\u3046\u3002\u3059\u306a\u308f\u3061\u3001\u6587\u5b57\u5217\u3092\u5236\u3059\u308b\u3082\u306e\u306f\u3001\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u3092\u5236\u3059\u308b\u306e\u3067\u3059\u3002<\/p>\n<p>\u306a\u304a\u3001\u3053\u306e\u8a18\u4e8b\u3067\u306f\u6df1\u304f\u89e6\u308c\u307e\u305b\u3093\u3067\u3057\u305f\u304c\u3001<span>WEB<\/span>\u306a\u3069\u306e\u591a\u8a00\u8a9e\u74b0\u5883\u3092\u524d\u63d0\u3068\u3057\u305f\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u3067\u306f\u3001\u3044\u308f\u3086\u308b\u6587\u5b57\u30b3\u30fc\u30c9\u306e\u77e5\u8b58<span>(<\/span>\u6587\u5b57\u96c6\u5408\u3001\u6587\u5b57\u7b26\u53f7\u5316\u65b9\u5f0f\u306a\u3069<span>)<\/span>\u304c\u5f37\u304f\u6c42\u3081\u3089\u308c\u307e\u3059\u3002<span>Java<\/span>\u3067\u306e\u6587\u5b57\u5217\u64cd\u4f5c\u306e\u3084\u308a\u65b9\u3068\u540c\u6642\u306b\u3001\u305d\u306e\u3088\u3046\u306a\u6587\u5b57\u306e\u4ed5\u7d44\u307f\u306b\u3064\u3044\u3066\u3082\u77e5\u8b58\u3092\u5897\u3084\u3057\u3066\u3044\u3063\u3066\u3044\u305f\u3060\u304d\u305f\u3044\u3067\u3059\u3002<\/p>\n<p>\u7686\u3055\u3093\u304c<span>String<\/span>\u3067\u306e\u6587\u5b57\u5217\u64cd\u4f5c\u306b\u6163\u308c\u308b\u3053\u3068\u3067\u3001<span>Java<\/span>\u3067\u6709\u76ca\u30fb\u52b9\u7387\u7684\u306a\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u304c\u3067\u304d\u308b\u3088\u3046\u306b\u306a\u308b\u3053\u3068\u3092\u9858\u3063\u3066\u3044\u307e\u3059\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>String\u3068\u306f\u6587\u5b57\u304c\u96c6\u307e\u3063\u3066\u3067\u304d\u305f\u300c\u6587\u5b57\u5217\u300d\u306e\u3053\u3068\u3067\u3001Java\u3067\u6271\u3048\u308b\u30c7\u30fc\u30bf\u306e\u4e2d\u3067\u306f\u57fa\u672c\u7684\u306a\u3082\u306e\u306e\u4e00\u3064\u3067\u3059\u3002 \u6587\u5b57\u5217\u3001\u3064\u307e\u308aString\u3092\u4f7f\u308f\u306a\u3044Java\u30d7\u30ed\u30b0\u30e9\u30e0\u306f\u306a\u3044\u3068\u8a00\u3063\u3066\u3082\u3044\u3044\u3067\u3057\u3087\u3046\u3002 \u3067\u3059\u304b\u3089\u3001String [&hellip;]<\/p>\n","protected":false},"author":3,"featured_media":804,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[14],"acf":[],"_links":{"self":[{"href":"https:\/\/www.bold.ne.jp\/engineer-club\/wp-json\/wp\/v2\/posts\/1367"}],"collection":[{"href":"https:\/\/www.bold.ne.jp\/engineer-club\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.bold.ne.jp\/engineer-club\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.bold.ne.jp\/engineer-club\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.bold.ne.jp\/engineer-club\/wp-json\/wp\/v2\/comments?post=1367"}],"version-history":[{"count":6,"href":"https:\/\/www.bold.ne.jp\/engineer-club\/wp-json\/wp\/v2\/posts\/1367\/revisions"}],"predecessor-version":[{"id":5770,"href":"https:\/\/www.bold.ne.jp\/engineer-club\/wp-json\/wp\/v2\/posts\/1367\/revisions\/5770"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.bold.ne.jp\/engineer-club\/wp-json\/wp\/v2\/media\/804"}],"wp:attachment":[{"href":"https:\/\/www.bold.ne.jp\/engineer-club\/wp-json\/wp\/v2\/media?parent=1367"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bold.ne.jp\/engineer-club\/wp-json\/wp\/v2\/categories?post=1367"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}