{"id":776,"date":"2018-10-16T12:00:37","date_gmt":"2018-10-16T03:00:37","guid":{"rendered":"https:\/\/www.bold.ne.jp\/engineer-club\/?p=776"},"modified":"2025-09-17T10:41:56","modified_gmt":"2025-09-17T01:41:56","slug":"java-array-initialization","status":"publish","type":"post","link":"https:\/\/www.bold.ne.jp\/engineer-club\/java-array-initialization","title":{"rendered":"Java\u914d\u5217\u306e\u521d\u671f\u5316\uff5c\u914d\u5217\u3092\u4f7f\u3046\u969b\u306b\u521d\u671f\u5024\u3092\u8a2d\u5b9a\u3059\u308b\u305f\u3081\u306e6\u3064\u306e\u65b9\u6cd5"},"content":{"rendered":"<p>\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u3067\u306e\u30c7\u30fc\u30bf\u69cb\u9020\u306e\u57fa\u672c\u306f\u914d\u5217\u3067\u3059\u3002\u914d\u5217\u3092\u4f7f\u3046\u969b\u306f\u3001\u4f55\u304b\u3057\u3089\u306e\u521d\u671f\u5024\u3092\u8a2d\u5b9a\u3057\u305f\u3044\u3067\u3059\u3088\u306d\u3002<\/p>\n<p>\u307e\u305f\u3001\u4f55\u304b\u5225\u306e\u30c7\u30fc\u30bf\u304b\u3089\u914d\u5217\u3092\u4f5c\u308a\u305f\u3044\u3053\u3068\u3082\u3042\u308b\u3067\u3057\u3087\u3046\u3002\u3053\u306e\u914d\u5217\u306e\u521d\u671f\u5316\u306b\u306f\u3001\u5927\u304d\u304f\u5206\u3051\u3066\u4ee5\u4e0b\u306e\u65b9\u6cd5\u304c\u3042\u308a\u307e\u3059<span>(Java 10<\/span>\u306e\u6642\u70b9<span>)<\/span>\u3002<\/p>\n<p>\u3053\u306e\u8a18\u4e8b\u3067\u306f\u3001\u305d\u308c\u305e\u308c\u306e\u65b9\u6cd5\u306b\u3064\u3044\u3066\u30b5\u30f3\u30d7\u30eb\u3092\u4ea4\u3048\u3066\u304a\u4f1d\u3048\u3057\u307e\u3059\u3002<\/p>\n<ol>\n<li><strong>\u914d\u5217\u306e\u5404\u8981\u7d20\u306b\u6dfb\u3048\u5b57\u3092\u4ecb\u3057\u3066\u5024\u3092\u8a2d\u5b9a\u3059\u308b<\/strong><\/li>\n<li><strong>\u914d\u5217\u3092\u30eb\u30fc\u30d7\u3055\u305b\u3066\u3001\u914d\u5217\u306e\u5404\u8981\u7d20\u306b\u5024\u3092\u8a2d\u5b9a\u3059\u308b<\/strong><\/li>\n<li><strong>\u914d\u5217\u306e\u5909\u6570\u306b\u3001\u914d\u5217\u306e\u5185\u5bb9\u3092\u8868\u73fe\u3057\u305f\u30d6\u30ed\u30c3\u30af\u3092\u4ee3\u5165\u3059\u308b<\/strong><\/li>\n<li><strong>\u4ed6\u306e\u914d\u5217\u304b\u3089\u5185\u5bb9\u3092\u30b3\u30d4\u30fc\u3059\u308b<\/strong><\/li>\n<li><strong>\u30b3\u30ec\u30af\u30b7\u30e7\u30f3(List\u3001Set\u3001Map)\u3084Stream\u304b\u3089\u914d\u5217\u3092\u751f\u6210\u3059\u308b<\/strong><\/li>\n<li><strong>\u56fa\u5b9a\u306e\u5024\u3067\u8a2d\u5b9a\u3059\u308b(Arrays.fill)<\/strong><\/li>\n<\/ol>\n<p>\u306a\u304a\u3001\u3053\u306e\u8a18\u4e8b\u3067\u306f\u300c\u914d\u5217\u306e\u521d\u671f\u5316\u300d\u3092\u300c\u914d\u5217\u3092\u4f7f\u3044\u59cb\u3081\u308b\u524d\u306b\u884c\u3046\u3001\u914d\u5217\u3078\u306e\u5024\u306e\u8a2d\u5b9a\u65b9\u6cd5\u300d\u3068\u3057\u3066\u3044\u307e\u3059\u3002\u53b3\u5bc6\u306b\u306f\u914d\u5217\u306e\u5ba3\u8a00\u30fb\u751f\u6210\u6642\u306b\u521d\u671f\u5024\u3092\u8a2d\u5b9a\u3059\u308b\u3053\u3068\u3068\u3001\u751f\u6210\u3057\u305f\u914d\u5217\u306b\u5024\u3092\u8a2d\u5b9a\u3059\u308b\u3053\u3068\u306f\u5225\u306e\u3053\u3068\u3067\u3059\u304c\u3001\u5e83\u3044\u610f\u5473\u3067\u306e\u521d\u671f\u5316\u3068\u3057\u3066\u6271\u3044\u307e\u3059\u3002<\/p>\n<p>\u672c\u8a18\u4e8b\u3067\u306f\u3001\u5206\u304b\u308a\u3084\u3059\u3055\u91cd\u8996\u3067<span>int<\/span>\u306e\u914d\u5217\u3068<span>Java<\/span>\u306e\u6a19\u6e96<span>API<\/span>\u3060\u3051\u3092\u4f7f\u3044\u307e\u3059\u3002<span>int<\/span>\u4ee5\u5916\u306e\u30d7\u30ea\u30df\u30c6\u30a3\u30d6\u578b\u3084\u53c2\u7167\u578b\u306e\u914d\u5217\u3067\u3082\u5927\u4f53\u540c\u3058\u3067\u3059\u3002\u591a\u6b21\u5143\u914d\u5217\u306e\u521d\u671f\u5316\u3067\u3082\u5927\u4f53\u540c\u3058\u3067\u3059\u304c\u3001\u5c11\u3057\u3084\u3084\u3053\u3057\u304f\u306a\u308a\u307e\u3059\u306e\u3067\u3001\u5404\u7bc0\u306b\u591a\u6b21\u5143\u914d\u5217\u7248\u3092\u500b\u5225\u306b\u8a18\u8f09\u3057\u3066\u3044\u308b\u3068\u3053\u308d\u3082\u3042\u308a\u307e\u3059\u3002<\/p>\n<div id=\"toc_container\" class=\"no_bullets\"><p class=\"toc_title\">\u76ee\u6b21<\/p><ul class=\"toc_list\"><li><a href=\"#Java\">\uff11\uff0eJava\u914d\u5217\u306e\u521d\u671f\u5316\u2460\uff1a\u914d\u5217\u306e\u5404\u8981\u7d20\u306b\u6dfb\u3048\u5b57\u3092\u4ecb\u3057\u3066\u5024\u3092\u8a2d\u5b9a\u3059\u308b<\/a><ul><li><a href=\"#i\">\uff11-\uff11\uff0e\u914d\u5217\u306e\u8981\u7d20\u3054\u3068\u306b\u5024\u3092\u8a2d\u5b9a\u3059\u308b<\/a><\/li><li><a href=\"#i-2\">\uff11-\uff12\uff0e\u914d\u5217\u306e\u521d\u671f\u5024\u3092\u6d3b\u7528\u3057\u3066\u697d\u3092\u3059\u308b<\/a><\/li><\/ul><\/li><li><a href=\"#Java-2\">\uff12\uff0eJava\u914d\u5217\u306e\u521d\u671f\u5316\u2461\uff1a\u914d\u5217\u3092\u30eb\u30fc\u30d7\u3055\u305b\u3066\u3001\u914d\u5217\u306e\u5404\u8981\u7d20\u306b\u5024\u3092\u8a2d\u5b9a\u3059\u308b<\/a><ul><li><a href=\"#i-3\">\uff12-\uff11\uff0e\u5168\u3066\u306e\u8981\u7d20\u306b\u8a2d\u5b9a\u3059\u308b\u5834\u5408<\/a><\/li><li><a href=\"#i-4\">\uff12-\uff12\uff0e\u4e00\u90e8\u306e\u8981\u7d20\u306b\u8a2d\u5b9a\u3059\u308b\u5834\u5408<\/a><\/li><li><a href=\"#-NGfor\">\uff12-\uff13\uff0eNG\u4f8b:\u62e1\u5f35for\u30eb\u30fc\u30d7<\/a><\/li><\/ul><\/li><li><a href=\"#Java-3\">\uff13\uff0eJava\u914d\u5217\u306e\u521d\u671f\u5316\u2462\uff1a\u914d\u5217\u306e\u5909\u6570\u306b\u3001\u914d\u5217\u306e\u5185\u5bb9\u3092\u8868\u73fe\u3057\u305f\u30d6\u30ed\u30c3\u30af\u3092\u4ee3\u5165\u3059\u308b<\/a><ul><li><a href=\"#i-5\">\uff13-\uff11\uff0e\u914d\u5217\u5ba3\u8a00\u6642\u306b\u56fa\u5b9a\u5024\u3092\u8a2d\u5b9a\u3059\u308b<\/a><\/li><li><a href=\"#i-6\">\uff13-\uff12\uff0e\u914d\u5217\u306e\u5909\u6570\u304c\u6307\u3059\u5148\u3092\u5f8c\u304b\u3089\u5909\u66f4\u3059\u308b<\/a><\/li><\/ul><\/li><li><a href=\"#Java-4\">\uff14\uff0eJava\u914d\u5217\u306e\u521d\u671f\u5316\u2463\uff1a\u9055\u3046\u914d\u5217\u304b\u3089\u5185\u5bb9\u3092\u30b3\u30d4\u30fc\u3059\u308b<\/a><ul><li><a href=\"#i-7\">\uff14-\uff11\uff0e\u30eb\u30fc\u30d7\u3067\u4e8c\u3064\u306e\u914d\u5217\u3092\u30b3\u30d4\u30fc\u3059\u308b<\/a><\/li><li><a href=\"#-Objectclone\">\uff14-\uff12\uff0eObject.clone\u3067\u30b3\u30d4\u30fc\u3059\u308b<\/a><\/li><li><a href=\"#-Systemarraycopy\">\uff14-\uff13\uff0eSystem.arraycopy\u3067\u30b3\u30d4\u30fc\u3059\u308b<\/a><\/li><li><a href=\"#-ArrayscopyOf\">\uff14-\uff14\uff0eArrays.copyOf\u3067\u30b3\u30d4\u30fc\u3059\u308b<\/a><\/li><li><a href=\"#-ArrayscopyOfRange\">\uff14-\uff13\uff0eArrays.copyOfRange\u3067\u30b3\u30d4\u30fc\u3059\u308b<\/a><\/li><\/ul><\/li><li><a href=\"#JavaListSetMap\">\uff15\uff0eJava\u914d\u5217\u306e\u521d\u671f\u5316\u2464\uff1a\u30b3\u30ec\u30af\u30b7\u30e7\u30f3(List\u3001Set\u3001Map)\u306a\u3069\u304b\u3089\u914d\u5217\u3092\u751f\u6210\u3059\u308b<\/a><ul><li><a href=\"#-CollectiontoArrayList\">\uff15-\uff11\uff0eCollection.toArray\u3092\u4f7f\u3046(List)<\/a><\/li><li><a href=\"#-CollectiontoArraySet\">\uff15-\uff12\uff0eCollection.toArray\u3092\u4f7f\u3046\u65b9\u6cd5(Set)<\/a><\/li><li><a href=\"#-CollectiontoArrayMap\">\uff15-\uff13\uff0eCollection.toArray\u3092\u4f7f\u3046(Map)<\/a><\/li><li><a href=\"#-StreamtoArray\">\uff15-\uff14\uff0eStream.toArray\u3092\u4f7f\u3046<\/a><\/li><\/ul><\/li><li><a href=\"#JavaArraysfill\">\uff16\uff0eJava\u914d\u5217\u306e\u521d\u671f\u5316\u2465\uff1aArrays.fill\u3067\u56fa\u5b9a\u5024\u3092\u8a2d\u5b9a\u3059\u308b<\/a><\/li><li><a href=\"#i-8\">\uff17\uff0e\u3055\u3044\u3054\u306b<\/a><\/li><\/ul><\/div>\n<h2><span id=\"Java\">\uff11\uff0eJava\u914d\u5217\u306e\u521d\u671f\u5316\u2460\uff1a\u914d\u5217\u306e\u5404\u8981\u7d20\u306b\u6dfb\u3048\u5b57\u3092\u4ecb\u3057\u3066\u5024\u3092\u8a2d\u5b9a\u3059\u308b<\/span><\/h2>\n<h3><span id=\"i\">\uff11-\uff11\uff0e\u914d\u5217\u306e\u8981\u7d20\u3054\u3068\u306b\u5024\u3092\u8a2d\u5b9a\u3059\u308b<\/span><\/h3>\n<p>\u6700\u3082\u57fa\u672c\u3068\u306a\u308b\u65b9\u6cd5\u3067\u3001\u914d\u5217\u306e\u6dfb\u3048\u5b57<span>(<\/span>\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u3068\u3082\u8a00\u3044\u307e\u3059<span>)<\/span>\u3054\u3068\u306b\u3001\u5024\u3092\u660e\u793a\u7684\u306b\u8a2d\u5b9a\u3059\u308b\u65b9\u6cd5\u3067\u3059\u3002<\/p>\n<p>\u914d\u5217\u306e\u6dfb\u3048\u5b57\u306e\u6570\u304c\u5c11\u306a\u3044\u3001\u3042\u308b\u3044\u306f\u56fa\u5b9a\u306a\u3089\u3053\u306e\u65b9\u6cd5\u3067\u3082\u5341\u5206\u3067\u3059\u3002<span>Java<\/span>\u3067\u306f\u3001\u914d\u5217\u306e\u6dfb\u3048\u5b57\u306f<span>0<\/span>\u304b\u3089\u59cb\u307e\u308b\u3053\u3068\u306b\u6ce8\u610f\u3057\u307e\u3057\u3087\u3046<span>(<\/span>\u4ed6\u306e\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u8a00\u8a9e\u3067\u306f\u3001<span>1<\/span>\u304b\u3089\u59cb\u307e\u308b\u3082\u306e\u3082\u3042\u308b\u306e\u3067\u3059<span>!!)<\/span>\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">int[] array = new int[3]; \/\/ 3\u3064\u5206\u306eint\u3092\u683c\u7d0d\u3067\u304d\u308b\u914d\u5217\u3092\u78ba\u4fdd\r\narray[0] = 12;\r\narray[1] = 34;\r\narray[2] = 56;\r\n\r\nSystem.out.println(java.util.Arrays.toString(array)); \/\/ \u2192 [12, 34, 56]<\/pre>\n<p>\u3044\u3064\u3082\u624b\u629c\u304d\u3092\u3059\u308b\u3053\u3068\u3092\u8003\u3048\u308b\u30d7\u30ed\u30b0\u30e9\u30de\u30fc\u304c\u826f\u304f\u4f7f\u3046\u306e\u306f\u3001\u6dfb\u3048\u5b57\u3092\u5909\u6570\u306b\u3059\u308b\u3053\u3068\u3067\u3059\u3002<\/p>\n<p>\u4f8b\u3048\u3070\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u3059\u308b\u3068\u3001\u9806\u756a\u3092\u5165\u308c\u66ff\u3048\u305f\u3044\u6642\u3067\u3082\u884c\u5358\u4f4d\u3067\u30ab\u30c3\u30c8<span>&amp;<\/span>\u30da\u30fc\u30b9\u30c8\u3059\u308b\u3060\u3051\u306a\u306e\u3067\u697d\u3061\u3093\u3067\u3059\u3002\u4ed6\u306b\u3082\u3001\u4f8b\u3048\u3070<span>JDBC<\/span>\u306e<span>ResultSet<\/span>\u304b\u3089\u5024\u3092\u53d6\u5f97\u3059\u308b\u6642\u306b\u3082\u3001\u540c\u3058\u3088\u3046\u306a\u3053\u3068\u3092\u3057\u305f\u308a\u3057\u307e\u3059\u306d\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">int[] array = new int[3];\r\nint index = 0;\r\narray[index++] = 12; \/\/ \u6dfb\u3048\u5b57\u3092\u76f4\u306b\u66f8\u304b\u305a\u3001\u5909\u6570\u3067\u8868\u73fe\u3059\u308b\r\narray[index++] = 34;\r\narray[index++] = 56;\r\n\r\nSystem.out.println(java.util.Arrays.toString(array)); \/\/ \u2192 [12, 34, 56]<\/pre>\n<h3><span id=\"i-2\">\uff11-\uff12\uff0e\u914d\u5217\u306e\u521d\u671f\u5024\u3092\u6d3b\u7528\u3057\u3066\u697d\u3092\u3059\u308b<\/span><\/h3>\n<p>Java\u306e\u914d\u5217\u306e\u5404\u8981\u7d20\u306b\u306f\u3001\u914d\u5217\u306e\u751f\u6210\u6642\u306b\u521d\u671f\u5024\u304c\u5fc5\u305a\u8a2d\u5b9a\u3055\u308c\u307e\u3059\u3002\u30eb\u30fc\u30eb\u306f\u30af\u30e9\u30b9\u306e\u30d5\u30a3\u30fc\u30eb\u30c9\u306e\u521d\u671f\u5024\u3068\u540c\u3058\u3067\u3001<span>int<\/span>\u306a\u3069\u306e\u6570\u5024\u578b\u30d7\u30ea\u30df\u30c6\u30a3\u30d6\u306a\u3089<span>0<\/span>\u3001<span>boolean<\/span>\u306a\u3089<span>false<\/span>\u3001<span>String<\/span>\u306a\u3069\u306e\u53c2\u7167\u578b\u306a\u3089<span>null<\/span>\u3067\u3059\u3002<\/p>\n<p>\u3067\u3059\u304b\u3089\u3001\u305d\u308c\u305e\u308c\u306e\u578b\u306e\u521d\u671f\u5024\u3067\u826f\u3044\u8981\u7d20\u306f\u3001\u660e\u793a\u7684\u306b\u5024\u3092\u8a2d\u5b9a\u3057\u306a\u304f\u3066\u3082\u826f\u3044\u306e\u3067\u3059\u3002\u521d\u671f\u5024\u3092\u4e0a\u624b\u304f\u4f7f\u3063\u3066\u3001\u306a\u308b\u3079\u304f\u697d\u3092\u3057\u307e\u3057\u3087\u3046\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">int[] array = new int[3]; \/\/ new\u3057\u305f\u6642\u70b9\u3067\u5168\u8981\u7d20\u304c0\u306b\u306a\u3063\u3066\u3044\u308b\r\narray[1] = 34; \/\/ \u6dfb\u3048\u5b571\u3060\u305134\u306b\u3059\u308b\u3001\u4ed6\u306f0\u306e\u307e\u307e\r\n\r\nSystem.out.println(java.util.Arrays.toString(array)); \/\/ \u2192 [0, 34, 0]<\/pre>\n<h2><span id=\"Java-2\">\uff12\uff0eJava\u914d\u5217\u306e\u521d\u671f\u5316\u2461\uff1a\u914d\u5217\u3092\u30eb\u30fc\u30d7\u3055\u305b\u3066\u3001\u914d\u5217\u306e\u5404\u8981\u7d20\u306b\u5024\u3092\u8a2d\u5b9a\u3059\u308b<\/span><\/h2>\n<h3><span id=\"i-3\">\uff12-\uff11\uff0e\u5168\u3066\u306e\u8981\u7d20\u306b\u8a2d\u5b9a\u3059\u308b\u5834\u5408<\/span><\/h3>\n<p>\u3053\u308c\u3082\u57fa\u672c\u7684\u306a\u65b9\u6cd5\u3067\u3059\u3002\u914d\u5217\u306e\u8981\u7d20\u6570\u304c\u5927\u304d\u3044\u5834\u5408\u3001\u3042\u308b\u3044\u306f\u7279\u5b9a\u306e\u8981\u7d20\u3060\u3051\u6761\u4ef6\u4ed8\u3051\u3066\u884c\u3044\u305f\u3044\u5834\u5408\u3001\u6dfb\u3048\u5b57\u306e\u6570\u5b57\u304b\u3089\u8003\u3048\u3089\u308c\u308b\u4f55\u304b\u306e\u30eb\u30fc\u30eb\u304c\u3042\u308b\u5834\u5408\u306f\u3001\u3053\u306e\u65b9\u6cd5\u3067\u884c\u3046\u306e\u304c\u4fbf\u5229\u3067\u3057\u3087\u3046\u3002<\/p>\n<p>\u5024\u3092\u8a2d\u5b9a\u3057\u305f\u3044\u7bc4\u56f2\u304c\u914d\u5217\u306e\u3059\u3079\u3066\u3067\u306f\u306a\u3044\u306a\u3089\u3001<span>for<\/span>\u6587\u3067\u306e\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u306e\u521d\u671f\u5024\u3001\u7d42\u4e86\u6761\u4ef6\u3001\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u306e\u52a0\u7b97\u51e6\u7406\u3092\u5909\u3048\u307e\u3057\u3087\u3046\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">int[] array = new int[3];\r\n\r\nfor (int i = 0; i &lt; array.length; i++) {\r\n\tarray[i] = i + 10; \/\/ \u6dfb\u3048\u5b57\u306b\u4e00\u5f8b10\u3092\u8db3\u3057\u305f\u5024\u3067\u521d\u671f\u5316\u3057\u3066\u3044\u307e\u3059\r\n}\r\n\r\nSystem.out.println(java.util.Arrays.toString(array)); \/\/ \u2192 [10, 11, 12]<\/pre>\n<p>\u3053\u308c\u3092\u5fdc\u7528\u3059\u308b\u3068\u3001\u4f55\u304b\u306e\u30d5\u30a1\u30a4\u30eb\u306b\u5024\u3092\u66f8\u304d\u8fbc\u3093\u3067\u304a\u3044\u3066\u3001\u305d\u308c\u3092\u914d\u5217\u306b\u4e00\u5ea6\u306b\u8a2d\u5b9a\u3067\u304d\u305f\u308a\u3057\u307e\u3059\u3002\u4f8b\u3048\u3070\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u611f\u3058\u3067\u3001\u30d5\u30a1\u30a4\u30eb\u306e\u884c\u3054\u3068\u306b\u8a18\u8ff0\u3057\u305f\u6570\u5024\u3092\u914d\u5217\u3078\u8a2d\u5b9a\u3067\u304d\u305f\u308a\u3057\u307e\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">\/\/ \u3053\u306e\u30b5\u30f3\u30d7\u30eb\u3092\u52d5\u304b\u3059\u306e\u306b\u5fc5\u8981\u306aimport\u6587\r\nimport java.nio.file.Files;\r\nimport java.nio.file.Paths;\r\nimport java.util.List;\r\n\r\nList&lt;String&gt; arraydata = Files.readAllLines(Paths.get(\"arraydata.txt\")); \/\/ \u30d5\u30a1\u30a4\u30eb\u304b\u3089\u30c7\u30fc\u30bf\u3092\u8aad\u307f\u53d6\u308b\r\nint[] array = new int[arraydata.size()]; \/\/ \u30d5\u30a1\u30a4\u30eb\u306e\u884c\u6570\u5206\u306e\u8981\u7d20\u3092\u6301\u3064\u914d\u5217\u3092\u751f\u6210\u3059\u308b\r\n\r\nfor (int i = 0; i &lt; arraydata.size(); i++) {\r\n\tarray[i] = Integer.parseInt(arraydata.get(i)); \/\/ \u884c\u306e\u5185\u5bb9\u3092int\u306b\u5909\u63db\u3057\u3066\u914d\u5217\u3078\u8a2d\u5b9a\r\n}\r\n\r\nSystem.out.println(java.util.Arrays.toString(array)); \/\/ \u2192 [10, 20, 30]\r\n\r\narraydata.txt\u306e\u5185\u5bb9\uff1a\r\n10\r\n20\r\n30<\/pre>\n<p>\u3053\u306e\u5fdc\u7528\u5148\u306f\u30d5\u30a1\u30a4\u30eb\u304b\u3089\u306e\u8aad\u307f\u51fa\u3057\u306b\u9650\u3089\u305a\u3001\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u304b\u3089\u306e\u8aad\u307f\u51fa\u3057\u3084\u3001\u30cd\u30c3\u30c8\u30ef\u30fc\u30af\u3092\u7d4c\u7531\u3057\u305f\u8aad\u307f\u51fa\u3057\u306a\u3069\u3001\u69d8\u3005\u3067\u3059\u3002<span>1<\/span>\u884c\u306e\u5185\u5bb9\u3082<span>1<\/span>\u3064\u306e\u5024\u3060\u3051\u3067\u306f\u306a\u304f<span>CSV<\/span>\u3068\u3059\u308b\u306a\u3069\u3059\u308c\u3070\u3001\u3082\u3063\u3068\u591a\u304f\u306e\u60c5\u5831\u3092\u8a70\u3081\u8fbc\u3081\u307e\u3059\u3002\u306a\u308b\u3079\u304f\u30d7\u30ed\u30b0\u30e9\u30e0\u4e0a\u3067\u306f\u697d\u3092\u3057\u305f\u3044\u3067\u3059\u306d\u3002<\/p>\n<h3><span id=\"i-4\">\uff12-\uff12\uff0e\u4e00\u90e8\u306e\u8981\u7d20\u306b\u8a2d\u5b9a\u3059\u308b\u5834\u5408<\/span><\/h3>\n<p>\u914d\u5217\u306e\u6dfb\u3048\u5b57\u3067\u30eb\u30fc\u30d7\u3092\u3057\u306a\u304c\u3089\u3001\u7279\u5b9a\u306e\u8981\u7d20\u306b\u3060\u3051\u5024\u3092\u8a2d\u5b9a\u3057\u305f\u3044\u306a\u3089\u3001\u30eb\u30fc\u30d7\u306e\u9014\u4e2d\u3067<span>if<\/span>\u6587\u3067\u5224\u5b9a\u3059\u308b\u3068\u826f\u3044\u3067\u3057\u3087\u3046\u3002<\/p>\n<p>\u3053\u3053\u3067\u306f\u4f8b\u3068\u3057\u3066\u3001\u5076\u6570\u306e\u6dfb\u3048\u5b57\u306e\u8981\u7d20\u306b\u3060\u3051\u5024\u3092\u8a2d\u5b9a\u3057\u3066\u307f\u307e\u3059\u3002\u3061\u306a\u307f\u306b\u3001\u3053\u306e<span>if<\/span>\u6587\u306e\u6761\u4ef6\u306f\u5076\u6570\u30fb\u5947\u6570\u5224\u5b9a\u306e\u30a4\u30c7\u30a3\u30aa\u30e0\u306a\u306e\u3067\u3001\u3064\u3044\u3067\u306b\u899a\u3048\u3066\u304a\u304d\u307e\u3057\u3087\u3046\u3002\u5947\u6570\u306e\u5834\u5408\u306f\u3001\u6bd4\u8f03\u3059\u308b\u5024\u304c<span>1<\/span>\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">int[] array = new int[3];\r\n\r\nfor (int i = 0; i &lt; array.length; i++) {\r\n\tif ((i % 2) == 0) {\r\n\t\tarray[i] = i + 10; \/\/ \u5076\u6570\u306e\u6dfb\u3048\u5b57(0\u30682\u3060\u3051)\u306b\u4e00\u5f8b10\u3092\u8db3\u3057\u3066\u3044\u307e\u3059\r\n\t}\r\n}\r\n\r\nSystem.out.println(java.util.Arrays.toString(array)); \/\/ \u2192 [10, 0, 12]<\/pre>\n<h3><span id=\"-NGfor\">\uff12-\uff13\uff0eNG\u4f8b<span>:<\/span>\u62e1\u5f35<span>for<\/span>\u30eb\u30fc\u30d7<\/span><\/h3>\n<p>\u62e1\u5f35<span>for<\/span>\u30eb\u30fc\u30d7\u306b\u3088\u308b\u30eb\u30fc\u30d7\u306e\u4e2d\u304b\u3089\u306f\u3001\u914d\u5217\u306e\u8981\u7d20\u3078\u306f\u5024\u3092\u8a2d\u5b9a\u3067\u304d\u306a\u3044\u3053\u3068\u306b\u6ce8\u610f\u3057\u307e\u3057\u3087\u3046\u3002<\/p>\n<p>\u306a\u305c\u304b\u3068\u8a00\u3046\u3068\u3001\u30eb\u30fc\u30d7\u3054\u3068\u306b\u4f7f\u7528\u3067\u304d\u308b\u5909\u6570\u306f\u3001\u30d7\u30ea\u30df\u30c6\u30a3\u30d6\u578b\u306e\u5834\u5408\u306f\u5404\u8981\u7d20\u306e\u30b3\u30d4\u30fc\u3055\u308c\u305f\u5024\u3001\u53c2\u7167\u578b\u306e\u5834\u5408\u306f\u5404\u8981\u7d20\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u6307\u3059\u30ed\u30fc\u30ab\u30eb\u5909\u6570\u3067\u3057\u304b\u306a\u3044\u304b\u3089\u3067\u3059\u3002<\/p>\n<p>\u914d\u5217\u306e\u5024\u3092\u8aad\u307f\u51fa\u3059\u3060\u3051\u306a\u3089\u62e1\u5f35<span>for<\/span>\u30eb\u30fc\u30d7\u306f\u4fbf\u5229\u3067\u3059\u304c\u3001\u914d\u5217\u306b\u5024\u3092\u8a2d\u5b9a\u3059\u308b\u306b\u306f\u3001\u914d\u5217\u3092\u6307\u3059\u5909\u6570\u3078\u306e\u6dfb\u3048\u5b57\u3092\u4ecb\u3057\u305f\u30a2\u30af\u30bb\u30b9\u304c\u57fa\u672c\u3068\u306a\u308a\u307e\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">int[] array = new int[3];\r\n\r\nfor (int a : array) {\r\n\ta = 10; \/\/ \u62e1\u5f35for\u30eb\u30fc\u30d7\u3067\u914d\u5217\u306e\u5185\u5bb9\u3092\u5168\u306610\u306b\u3057\u3088\u3046\u3068\u3057\u3066\u3044\u308b\u304c\u3001\u3053\u308c\u3067\u306f\u99c4\u76ee\r\n}\r\n\r\nSystem.out.println(java.util.Arrays.toString(array)); \/\/ \u2192 [0, 0, 0] \u521d\u671f\u5024(0)\u304b\u3089\u5909\u308f\u3063\u3066\u3044\u307e\u305b\u3093!!<\/pre>\n<h2><span id=\"Java-3\">\uff13\uff0eJava\u914d\u5217\u306e\u521d\u671f\u5316\u2462\uff1a\u914d\u5217\u306e\u5909\u6570\u306b\u3001\u914d\u5217\u306e\u5185\u5bb9\u3092\u8868\u73fe\u3057\u305f\u30d6\u30ed\u30c3\u30af\u3092\u4ee3\u5165\u3059\u308b<\/span><\/h2>\n<h3><span id=\"i-5\">\uff13-\uff11\uff0e\u914d\u5217\u5ba3\u8a00\u6642\u306b\u56fa\u5b9a\u5024\u3092\u8a2d\u5b9a\u3059\u308b<\/span><\/h3>\n<p>\u914d\u5217\u306b\u56fa\u5b9a\u3055\u308c\u305f\u5024\u3092\u8a2d\u5b9a\u3059\u308c\u3070\u3044\u3044\u306e\u306a\u3089\u3001\u3053\u308c\u304c\u304a\u52e7\u3081\u3067\u3059\u3002<span>{}<\/span>\u3067\u56f2\u3063\u305f\u7bc4\u56f2<span>(<\/span>\u3053\u308c\u3092<span>Java<\/span>\u3067\u306f\u30d6\u30ed\u30c3\u30af\u3068\u547c\u3073\u307e\u3059<span>)<\/span>\u304c\u914d\u5217\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u623b\u3059\u306e\u3060\u3068\u8003\u3048\u3066\u304f\u3060\u3055\u3044\u3002<\/p>\n<p>\u3053\u308c\u3060\u3068\u914d\u5217\u306e\u8981\u7d20\u6570\u3092\u8a18\u8ff0\u3057\u306a\u304f\u3066\u3082\u3044\u3044\u306e\u3067\u3001\u3068\u3066\u3082\u697d\u3061\u3093\u3067\u3059\u306d<span>!! <\/span>\u305f\u3060\u3057\u3001\u914d\u5217\u306e\u5168\u8981\u7d20\u306e\u5024\u3092\u8a18\u8ff0\u3057\u306a\u3051\u308c\u3070\u306a\u3089\u306a\u3044\u306e\u3067\u3001\u5024\u306e\u6570\u304c\u591a\u3044\u3068\u5927\u5909\u3067\u3059\u3002\u305d\u306e\u5834\u5408\u306f\u524d\u8ff0\u3057\u305f\u30eb\u30fc\u30d7\u3084\u30d5\u30a1\u30a4\u30eb\u304b\u3089\u306e\u8aad\u307f\u8fbc\u307f\u3092\u8003\u3048\u3066\u307f\u307e\u3057\u3087\u3046\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">int[] array = { 12, 34, 56 };\r\n\/* int[] array = new int[] { 12, 34, 56 }; \/\/ \u3053\u308c\u3067\u3082\u610f\u5473\u306f\u540c\u3058\u3067\u3059\u3002 *\/\r\n\r\nSystem.out.println(java.util.Arrays.toString(array)); \/\/ \u2192 [12, 34, 56]<\/pre>\n<p>\u591a\u6b21\u5143\u914d\u5217\u306e\u5834\u5408\u306f\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3002\u6700\u3082\u9ad8\u3044\u6b21\u5143\u306e\u914d\u5217\u306e\u30d6\u30ed\u30c3\u30af\u306e\u4e2d\u306b\u3001\u6b21\u306e\u6b21\u5143\u306e\u914d\u5217\u306e\u30d6\u30ed\u30c3\u30af\u3092\u57cb\u3081\u8fbc\u3080\u3068\u3044\u3046\u611f\u3058\u3067\u3059\u3002\u6b21\u5143\u304c\u5897\u3048\u308c\u3070\u5897\u3048\u308b\u307b\u3069\u3001\u5185\u90e8\u306b\u57cb\u3081\u8fbc\u3080\u30d6\u30ed\u30c3\u30af\u304c\u5897\u3048\u3066\u3044\u304d\u307e\u3059\u3002<\/p>\n<p>\u3053\u306e\u4f8b\u3067\u306f<span>2<\/span>\u6b21\u5143\u914d\u5217\u3067\u3059\u3002<span>2<\/span>\u6b21\u5143\u914d\u5217\u306e<span>1<\/span>\u756a\u76ee<span>(array[0])<\/span>\u306f\u8981\u7d20\u304c<span>3<\/span>\u3064\u306e\u914d\u5217\u3001<span>2<\/span>\u756a\u76ee<span>(array[1])<\/span>\u306f\u8981\u7d20\u304c<span>2<\/span>\u3064\u306e\u914d\u5217\u3067\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">int[][] array = {{11, 12, 13}, {21, 22}};\r\n\r\nSystem.out.println(java.util.Arrays.deepToString(array)); \/\/ \u2192 [[11, 12, 13], [21, 22]]<\/pre>\n<p>3\u6b21\u5143\u914d\u5217\u306e\u5834\u5408\u306f\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3002<span>{}<\/span>\u304c\u4e00\u3064\u306e\u914d\u5217\u3067\u3001\u305d\u308c\u304c\u5165\u308c\u5b50\u306b\u306a\u3063\u3066\u3044\u308b\u3068\u3044\u3046\u69cb\u9020\u306f\u5909\u308f\u308a\u307e\u305b\u3093\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">int[][][] array = {\r\n\t{\r\n\t\t{ 11, 12, 13 },\r\n\t\t{ 21, 22, 23 }\r\n\t},\r\n\t{\r\n\t\t{ 31, 32, 33 },\r\n\t\t{ 41, 42, 43 }\r\n\t}\r\n};\r\n\r\nSystem.out.println(java.util.Arrays.deepToString(array)); \/\/ \u2192 [[[11, 12, 13], [21, 22, 23]], [[31, 32, 33], [41, 42, 43]]]<\/pre>\n<p>\u914d\u5217\u306e\u6b21\u5143\u304c\u591a\u304f\u306a\u308b\u3068\u3001\u30a4\u30f3\u30c7\u30f3\u30c8\u3059\u308c\u3070\u307e\u3060\u8aad\u3081\u307e\u3059\u304c\u3001\u305d\u308c\u3067\u3082\u3054\u89a7\u306e\u901a\u308a\u3069\u3093\u3069\u3093\u3084\u3084\u3053\u3057\u304f\u306a\u308a\u307e\u3059\u3002\u3067\u3059\u304b\u3089\u3001\u6b21\u5143\u304c\u5927\u304d\u3044\u5834\u5408\u306f\u30d7\u30ed\u30b0\u30e9\u30e0\u3067\u521d\u671f\u5316\u3092\u3057\u305f\u65b9\u304c\u5206\u304b\u308a\u3084\u3059\u304f\u306a\u308b\u3067\u3057\u3087\u3046\u3002<\/p>\n<h3><span id=\"i-6\">\uff13-\uff12\uff0e\u914d\u5217\u306e\u5909\u6570\u304c\u6307\u3059\u5148\u3092\u5f8c\u304b\u3089\u5909\u66f4\u3059\u308b<\/span><\/h3>\n<p>\u5225\u306b\u5ba3\u8a00\u3057\u305f\u914d\u5217\u306b\u5225\u306e\u914d\u5217\u3092\u518d\u4ee3\u5165\u3067\u304d\u307e\u3059\u306e\u3067\u3001\u3053\u308c\u3092\u521d\u671f\u5316\u306e\u4ee3\u308f\u308a\u306b\u3057\u3066\u3082\u826f\u3044\u3067\u3057\u3087\u3046\u3002\u8981\u306f\u3001\u65b0\u3057\u3044\u914d\u5217\u3092\u3082\u3046\u4e00\u3064\u751f\u6210\u3057\u3001\u914d\u5217\u306e\u5909\u6570\u304c\u6307\u3059\u5148\u3092\u65b0\u3057\u3044\u914d\u5217\u306b\u5909\u66f4\u3057\u3066\u3044\u308b\u3068\u3044\u3046\u3053\u3068\u3067\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">int[] array = { 1, 2, 3 };\r\n\r\nSystem.out.println(java.util.Arrays.toString(array)); \/\/ \u2192 [1, 2, 3]\r\n\r\narray = new int[] { 12, 34, 56 }; \/\/ array\u306e\u6307\u3059\u5148\u306e\u914d\u5217\u3092\u65b0\u3057\u304f\u751f\u6210\u3057\u305f\u914d\u5217\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u306b\u3059\u308b\r\n\r\nSystem.out.println(java.util.Arrays.toString(array)); \/\/ \u2192 [12, 34, 56]<\/pre>\n<p>\u914d\u5217\u306f\u53c2\u7167\u578b\u306e\u5909\u6570\u3067\u3059\u3002\u3067\u3059\u304b\u3089\u3001\u914d\u5217\u306e\u5909\u6570\u304c\u6307\u3059\u5148\u306e\u5b9f\u4f53\u3067\u3042\u308b\u914d\u5217\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3068\u3067\u3082\u547c\u3076\u3079\u304d\u3082\u306e\u3092\u3001\u3044\u3064\u3067\u3082\u5909\u66f4\u3067\u304d\u308b\u306e\u3067\u3059\u3002<\/p>\n<p>\u591a\u6b21\u5143\u914d\u5217\u3082\u540c\u3058\u8003\u3048\u3067\u3001\u4f8b\u3048\u3070<span>2<\/span>\u6b21\u5143\u914d\u5217\u306e<span>1<\/span>\u6b21\u5143\u76ee\u306f\u3001\u5225\u306e\u914d\u5217\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u6307\u3057\u3066\u3044\u308b\u3060\u3051\u306a\u306e\u3067\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">int[][] array1 = { { 11, 12, 13 }, { 21, 22 } };\r\nint[][] array2 = new int[2][]; \/\/ \u7a7a\u306e2\u6b21\u5143\u914d\u5217\u3092\u751f\u6210\u3057\u305f\u3060\u3051\u306a\u306e\u3067\u3001[null, null] \u306e\u72b6\u614b\r\n\r\narray2[0] = array1[1]; \/\/ array2\u306e\u6dfb\u3048\u5b570\u304c\u6307\u3059\u5148\u3092\u3001array1\u306e\u6dfb\u3048\u5b571\u306e\u914d\u5217\u306b\u3059\u308b\r\n\r\nSystem.out.println(java.util.Arrays.deepToString(array2)); \/\/ \u2192 [[21, 22], null]<\/pre>\n<h2><span id=\"Java-4\">\uff14\uff0eJava\u914d\u5217\u306e\u521d\u671f\u5316\u2463\uff1a\u9055\u3046\u914d\u5217\u304b\u3089\u5185\u5bb9\u3092\u30b3\u30d4\u30fc\u3059\u308b<\/span><\/h2>\n<h3><span id=\"i-7\">\uff14-\uff11\uff0e\u30eb\u30fc\u30d7\u3067\u4e8c\u3064\u306e\u914d\u5217\u3092\u30b3\u30d4\u30fc\u3059\u308b<\/span><\/h3>\n<p>\u6642\u306b\u306f\u3001\u4ed6\u306e\u914d\u5217\u306e\u5185\u5bb9\u3092\u30b3\u30d4\u30fc\u3057\u3066\u521d\u671f\u5316\u3068\u3057\u305f\u3044\u5834\u5408\u3082\u3042\u308b\u3067\u3057\u3087\u3046\u3002\u305d\u306e\u5834\u5408\u306e\u57fa\u672c\u5f62\u306f\u3001\u30eb\u30fc\u30d7\u3067\u30b3\u30d4\u30fc\u5143\u30fb\u5148\u306e\u914d\u5217\u306e\u5024\u3092\u30b3\u30d4\u30fc\u3059\u308b\u3053\u3068\u3067\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">int[] array1 = { 1, 2, 3 };\r\nint[] array2 = new int[array1.length]; \/\/ \u5168\u3066\u306e\u8981\u7d20\u306f\u521d\u671f\u5024\u306e0\r\n\r\nfor (int i = 0; i &lt; array1.length; i++) {\r\n\tarray2[i] = array1[i];\r\n}\r\n\r\nSystem.out.println(java.util.Arrays.toString(array2)); \/\/ \u2192 [1, 2, 3]<\/pre>\n<p>int\u306a\u3069\u306e\u30d7\u30ea\u30df\u30c6\u30a3\u30d6\u578b\u306e\u914d\u5217\u306a\u3089\u3070\u3053\u308c\u3067\u554f\u984c\u306f\u3042\u308a\u307e\u305b\u3093\u3002\u30b3\u30d4\u30fc\u5148\u3068\u30b3\u30d4\u30fc\u5143\u306e\u914d\u5217\u3067\u6301\u3063\u3066\u3044\u308b\u5024\u306f\u5225\u3005\u306e\u3082\u306e\u306b\u306a\u308b\u306e\u3067\u3001\u7247\u65b9\u306e\u914d\u5217\u306e\u8a2d\u5b9a\u5024\u306e\u5909\u66f4\u306f\u3001\u304a\u4e92\u3044\u306e\u914d\u5217\u3078\u5f71\u97ff\u3092\u53ca\u307c\u3059\u3053\u3068\u306f\u3042\u308a\u307e\u305b\u3093\u3002<\/p>\n<p>\u3067\u3059\u304c\u3001\u53c2\u7167\u578b\u306e\u914d\u5217\u306f\u8981\u6ce8\u610f\u3067\u3059\u3002\u53c2\u7167\u5148\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u304c\u30b3\u30d4\u30fc\u5143\u3068\u30b3\u30d4\u30fc\u5148\u306e\u914d\u5217\u3067\u540c\u3058\u306b\u306a\u308b\u304b\u3089\u3067\u3059\u3002\u8a73\u7d30\u306a\u8aac\u660e\u306f\u7701\u304d\u307e\u3059\u304c\u3001\u8208\u5473\u304c\u3042\u308b\u65b9\u306f\u30b7\u30e3\u30ed\u30fc\u30b3\u30d4\u30fc<span>(shallow copy)<\/span>\u3068\u30c7\u30a3\u30fc\u30d7\u30b3\u30d4\u30fc<span>(deep copy)<\/span>\u3067\u8abf\u3079\u3066\u307f\u308b\u3068\u826f\u3044\u3067\u3057\u3087\u3046\u3002<\/p>\n<h3><span id=\"-Objectclone\">\uff14-\uff12\uff0eObject.clone\u3067\u30b3\u30d4\u30fc\u3059\u308b<\/span><\/h3>\n<p>\u81ea\u5206\u3067\u914d\u5217\u3092\u30eb\u30fc\u30d7\u3092\u3057\u3066\u3082\u3044\u3044\u3067\u3059\u304c\u3001\u5358\u7d14\u306a\u5024\u306e\u30b3\u30d4\u30fc\u3092\u3059\u308b\u3060\u3051\u306a\u3089<span>clone<\/span>\u3092\u3057\u3066\u3082\u3044\u3044\u3067\u3057\u3087\u3046\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">int[] array1 = { 1, 2, 3 };\r\nint[] array2 = array1.clone();\r\n\r\nSystem.out.println(java.util.Arrays.toString(array2)); \/\/ \u2192 [1, 2, 3]<\/pre>\n<p>\u53c2\u7167\u578b\u306e\u914d\u5217\u306e\u5834\u5408\u3082\u540c\u69d8\u3067\u3059\u3002\u65b0\u3057\u3044\u914d\u5217\u306e\u5404\u8981\u7d20\u306f\u3001\u5143\u306e\u914d\u5217\u304c\u6307\u3057\u3066\u3044\u305f\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u6307\u3057\u3066\u3044\u308b\u3060\u3051\u3068\u3044\u3046\u3053\u3068\u306b\u306f\u6c17\u3092\u4ed8\u3051\u307e\u3057\u3087\u3046\u3002\u4e8c\u3064\u306e\u914d\u5217\u3067\u540c\u3058\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u5171\u6709\u3057\u3066\u3044\u308b\u3068\u3044\u3046\u3053\u3068\u3067\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">String[] array1 = {\"A\", \"B\"};\r\nString[] array2 = array1.clone();\r\n\r\nSystem.out.println(java.util.Arrays.toString(array2)); \/\/ \u2192 [A, B]<\/pre>\n<h3><span id=\"-Systemarraycopy\">\uff14-\uff13\uff0eSystem.arraycopy\u3067\u30b3\u30d4\u30fc\u3059\u308b<\/span><\/h3>\n<p>clone\u3067\u306f\u5168\u4f53\u304c\u30b3\u30d4\u30fc\u3055\u308c\u307e\u3059\u3002\u5834\u5408\u306b\u3088\u3063\u3066\u306f\u914d\u5217\u306e\u4e00\u90e8\u3060\u3051\u3092\u30b3\u30d4\u30fc\u3057\u305f\u3044\u3053\u3068\u3082\u3042\u308b\u3067\u3057\u3087\u3046\u3002\u305d\u306e\u6642\u306b\u4f7f\u3048\u308b\u306e\u306f\u3001\u307e\u305a\u306f<span>System.arraycopy<\/span>\u3067\u3059\u3002<\/p>\n<p><span class=\"f-marker-p\">\u30af\u30e9\u30b9\uff1a<\/span><\/p>\n<pre class=\"prettyprint lang:default decode:true\">java.lang.System<\/pre>\n<p><span class=\"f-marker-w\">\u30e1\u30bd\u30c3\u30c9\uff1a<\/span><\/p>\n<pre class=\"prettyprint lang:default decode:true\">public static void arraycopy(Object src, int srcPos, Object dest, int destPos, int length)\r\n\t\tsrc - \u8ee2\u9001\u5143\u914d\u5217\r\n\t\tsrcPos - \u30bd\u30fc\u30b9\u914d\u5217\u306e\u958b\u59cb\u4f4d\u7f6e\r\n\t\tdest - \u8ee2\u9001\u5148\u914d\u5217\r\n\t\tdestPos - \u8ee2\u9001\u5148\u30c7\u30fc\u30bf\u5185\u306e\u958b\u59cb\u4f4d\u7f6e\r\n\t\tlength - \u30b3\u30d4\u30fc\u3055\u308c\u308b\u914d\u5217\u8981\u7d20\u306e\u6570\r\n\r\nint[] array1 = { 1, 2, 3 };\r\nint[] array2 = new int[array1.length]; \/\/ \u9577\u3055\u306farray1\u3068\u540c\u3058\u3001\u5168\u3066\u306e\u8981\u7d20\u306f\u521d\u671f\u5024\u306e0\r\nint[] array3 = new int[array1.length]; \/\/ \u540c\u4e0a\r\n\r\nSystem.arraycopy(array1, 0, array2, 0, array1.length); \/\/ array1\u306e\u5168\u8981\u7d20(0\u304b\u3089\u6700\u5f8c\u307e\u3067)\u3092\u30b3\u30d4\u30fc\u3059\u308b\r\nSystem.arraycopy(array1, 0, array3, 0, 1); \/\/ array1\u306e\u4e00\u90e8\u5206(0\u304b\u30891\u307e\u3067)\u3092\u30b3\u30d4\u30fc\u3059\u308b\r\nSystem.out.println(java.util.Arrays.toString(array2)); \/\/ \u2192 [1, 2, 3]\r\nSystem.out.println(java.util.Arrays.toString(array3)); \/\/ \u2192 [1, 2, 0]<\/pre>\n<h3><span id=\"-ArrayscopyOf\">\uff14-\uff14\uff0eArrays.copyOf\u3067\u30b3\u30d4\u30fc\u3059\u308b<\/span><\/h3>\n<p>System.arraycopy\u3067\u306f\u3001\u30b3\u30d4\u30fc\u5143\u30fb\u5148\u306e\u4e8c\u3064\u306e\u914d\u5217\u3092\u3042\u3089\u304b\u3058\u3081\u7528\u610f\u3059\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u3057\u305f\u3002<span>Arrays.copyOf<\/span>\u3067\u306f\u3001<span>System.arraycopy<\/span>\u3068\u4f3c\u305f\u3088\u3046\u306a\u52d5\u304d\u3092\u3057\u307e\u3059\u304c\u3001\u30b3\u30d4\u30fc\u5143\u306e\u914d\u5217\u3060\u3051\u304c\u3042\u308c\u3070<span>OK<\/span>\u3067\u3059\u3002<\/p>\n<p>\u3057\u304b\u3082\u3001\u4e0d\u8981\u306a\u90e8\u5206\u304c\u3042\u308c\u3070\u305d\u308c\u3092\u9664\u5916\u3059\u308b\u3053\u3068\u3082\u3067\u304d\u307e\u3059\u3002\u3067\u3059\u304c\u3001<span>Arrays.copyOf<\/span>\u306e\u5834\u5408\u306f\u30b3\u30d4\u30fc\u306e\u958b\u59cb\u4f4d\u7f6e\u304c<span>0<\/span>\u756a\u76ee\u304b\u3089\u306a\u306e\u3067\u6ce8\u610f\u3057\u307e\u3057\u3087\u3046\u3002<\/p>\n<p><span class=\"f-marker-p\">\u30af\u30e9\u30b9\uff1a<\/span><\/p>\n<pre class=\"prettyprint lang:default decode:true\">java.util.Arrays<\/pre>\n<p><span class=\"f-marker-w\">\u30e1\u30bd\u30c3\u30c9\uff1a<\/span><\/p>\n<pre class=\"prettyprint lang:default decode:true\">public static &lt;T,U&gt; T[] copyOf(U[] original, int newLength, Class&lt;? extends T[]&gt; newType)\r\npublic static byte[] copyOf(byte[] original, int newLength)\r\npublic static short[] copyOf(short[] original, int newLength)\r\npublic static int[] copyOf(int[] original, int newLength)\r\npublic static long[] copyOf(long[] original, int newLength)\r\npublic static char[] copyOf(char[] original, int newLength)\r\npublic static float[] copyOf(float[] original, int newLength)\r\npublic static double[] copyOf(double[] original, int newLength)\r\npublic static boolean[] copyOf(boolean[] original, int newLength)<\/pre>\n<div class=\"attention a-3\">\n<p class=\"attention-title\" style=\"text-align: left;\">\u5f15\u6570\u306e\u610f\u5473<\/p>\n<ul>\n<li>original &#8211; \u7bc4\u56f2\u306e\u30b3\u30d4\u30fc\u5148\u3068\u306a\u308b\u914d\u5217<\/li>\n<li>newLength &#8211; \u8fd4\u3055\u308c\u308b\u30b3\u30d4\u30fc\u306e\u9577\u3055<\/li>\n<\/ul>\n<\/div>\n<pre class=\"prettyprint lang:default decode:true\">int[] array1 = { 1, 2, 3 };\r\nint[] array2 = Arrays.copyOf(array1, array1.length); \/\/ \u540c\u3058\u9577\u3055\u306e\u914d\u5217\u3092\u4f5c\u308a\u3001\u5168\u8981\u7d20\u3092\u30b3\u30d4\u30fc\r\nint[] array3 = Arrays.copyOf(array1, 5); \/\/ \u9577\u30555\u306e\u914d\u5217\u3092\u4f5c\u308a\u3001\u8ffd\u52a0\u8981\u7d20\u306f\u30c7\u30d5\u30a9\u30eb\u30c8\u306e0\r\nint[] array4 = Arrays.copyOf(array1, 2); \/\/ \u9577\u30552\u306e\u914d\u5217\u3092\u4f5c\u308a\u3001\u9577\u3055\u304c\u8db3\u308a\u306a\u3044\u90e8\u5206\u306f\u9664\u5916\r\n\r\nSystem.out.println(java.util.Arrays.toString(array2)); \/\/ \u2192 [1, 2, 3]\r\nSystem.out.println(java.util.Arrays.toString(array3)); \/\/ \u2192 [1, 2, 3, 0, 0]\r\nSystem.out.println(java.util.Arrays.toString(array4)); \/\/ \u2192 [1, 2]<\/pre>\n<h3><span id=\"-ArrayscopyOfRange\">\uff14-\uff13\uff0eArrays.copyOfRange\u3067\u30b3\u30d4\u30fc\u3059\u308b<\/span><\/h3>\n<p>Arrays.copyOf\u306f\u4fbf\u5229\u306a\u3082\u306e\u3067\u3057\u305f\u304c\u3001\u30b3\u30d4\u30fc\u306e\u7bc4\u56f2\u3092\u5909\u3048\u305f\u3051\u308c\u3070<span>Arrays.copyOfRange<\/span>\u306e\u65b9\u304c\u826f\u3044\u3067\u3057\u3087\u3046\u3002<\/p>\n<p><span class=\"f-marker-p\">\u30af\u30e9\u30b9\uff1a<\/span><\/p>\n<pre class=\"prettyprint lang:default decode:true\">java.util.Arrays<\/pre>\n<p><span class=\"f-marker-w\">\u30e1\u30bd\u30c3\u30c9\uff1a<\/span><\/p>\n<pre class=\"prettyprint lang:default decode:true\">public static &lt;T,U&gt; T[] copyOfRange(U[] original, int from, int to, Class&lt;? extends T[]&gt; newType)\r\npublic static byte[] copyOfRange(byte[] original, int from, int to)\r\npublic static short[] copyOfRange(short[] original, int from, int to)\r\npublic static int[] copyOfRange(int[] original, int from, int to)\r\npublic static long[] copyOfRange(long[] original, int from, int to)\r\npublic static char[] copyOfRange(char[] original, int from, int to)\r\npublic static float[] copyOfRange(float[] original, int from, int to)\r\npublic static double[] copyOfRange(double[] original, int from, int to)\r\npublic static boolean[] copyOfRange(boolean[] original, int from, int to)<\/pre>\n<div class=\"attention a-3\">\n<p class=\"attention-title\" style=\"text-align: left;\">\u5f15\u6570\u306e\u610f\u5473<\/p>\n<ul>\n<li>original &#8211; \u7bc4\u56f2\u306e\u30b3\u30d4\u30fc\u5148\u3068\u306a\u308b\u914d\u5217<\/li>\n<li>from &#8211; \u30b3\u30d4\u30fc\u3055\u308c\u308b\u7bc4\u56f2\u306e\u6700\u521d\u306e\u30a4\u30f3\u30c7\u30c3\u30af\u30b9(\u3053\u308c\u3092\u542b\u3080\uff09<\/li>\n<li>to &#8211; \u30b3\u30d4\u30fc\u3055\u308c\u308b\u7bc4\u56f2\u306e\u6700\u5f8c\u306e\u30a4\u30f3\u30c7\u30c3\u30af\u30b9(\u3053\u308c\u3092\u542b\u307e\u306a\u3044)\u3002 (\u3053\u306e\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u306f\u914d\u5217\u306e\u5916\u5074\u306b\u5b58\u5728\u3059\u308b\u3053\u3068\u3082\u3042\u308b\u3002)<\/li>\n<\/ul>\n<\/div>\n<pre class=\"prettyprint lang:default decode:true\">int[] array1 = { 1, 2, 3 };\r\nint[] array2 = Arrays.copyOfRange(array1, 0, array1.length); \/\/ \u540c\u3058\u9577\u3055\u306e\u914d\u5217\u3092\u4f5c\u308a\u3001\u5168\u8981\u7d20\u3092\u30b3\u30d4\u30fc(copyOf\u3068\u540c\u3058\u52d5\u4f5c)\r\nint[] array3 = Arrays.copyOfRange(array1, 0, 5); \/\/ \u914d\u5217\u306e\u6dfb\u3048\u5b571\uff5e3\u307e\u3067\u30b3\u30d4\u30fc\u3057\u3001\u5168\u4f53\u3067\u9577\u30555\u306e\u914d\u5217\u3092\u4f5c\u308b\r\nint[] array4 = Arrays.copyOfRange(array1, 1, 3); \/\/ \u914d\u5217\u306e\u6dfb\u3048\u5b571\uff5e2\u307e\u3067\u30b3\u30d4\u30fc\u3059\u308b\r\n\r\nSystem.out.println(java.util.Arrays.toString(array2)); \/\/ \u2192 [1, 2, 3]\r\nSystem.out.println(java.util.Arrays.toString(array3)); \/\/ \u2192 [1, 2, 3, 0, 0]\r\nSystem.out.println(java.util.Arrays.toString(array4)); \/\/ \u2192 [2, 3]<\/pre>\n<h2><span id=\"JavaListSetMap\">\uff15\uff0eJava\u914d\u5217\u306e\u521d\u671f\u5316\u2464\uff1a\u30b3\u30ec\u30af\u30b7\u30e7\u30f3<span>(List<\/span>\u3001<span>Set<\/span>\u3001<span>Map)<\/span>\u306a\u3069\u304b\u3089\u914d\u5217\u3092\u751f\u6210\u3059\u308b<\/span><\/h2>\n<p>\u30b3\u30ec\u30af\u30b7\u30e7\u30f3\u3068\u3057\u3066\u3088\u304f\u4f7f\u3046\u306e\u306f<span>List<\/span>\u3001<span>Set<\/span>\u3001<span>Map<\/span>\u3060\u3068\u601d\u3044\u307e\u3059\u3002\u3053\u3053\u3067\u306f\u3001\u3053\u308c\u3089\u306e\u30b3\u30ec\u30af\u30b7\u30e7\u30f3\u304b\u3089\u914d\u5217\u3068\u3057\u3066\u30c7\u30fc\u30bf\u3092\u53d6\u308a\u51fa\u3059\u65b9\u6cd5\u3092\u304a\u4f1d\u3048\u3057\u307e\u3059\u3002<\/p>\n<h3><span id=\"-CollectiontoArrayList\">\uff15-\uff11\uff0eCollection.toArray\u3092\u4f7f\u3046<span>(List)<\/span><\/span><\/h3>\n<p>List\u306b\u683c\u7d0d\u3055\u308c\u3066\u3044\u308b\u5185\u5bb9\u3092\u914d\u5217\u3068\u3057\u3066\u53c2\u7167\u3057\u305f\u3044\u3053\u3068\u3082\u3042\u308b\u3067\u3057\u3087\u3046\u3002\u3082\u3061\u308d\u3093\u3001\u7c21\u5358\u306b\u3067\u304d\u307e\u3059\u3002\u4f8b\u3048\u3070\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u611f\u3058\u3067\u3059\u3002\u3053\u306e\u5834\u5408\u306f\u3001<span>List<\/span>\u5185\u3067\u306e\u683c\u7d0d\u9806\u5e8f\u3068\u3001\u914d\u5217\u5185\u306e\u6dfb\u3048\u5b57\u306e\u9806\u5e8f\u306f\u540c\u3058\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">List&lt;Integer&gt; list = Arrays.asList(1, 2, 3);\r\nInteger[] array = list.toArray(new Integer[list.size()]);\r\n\r\nSystem.out.println(java.util.Arrays.toString(array)); \/\/ \u2192 [1, 2, 3]<\/pre>\n<h3><span id=\"-CollectiontoArraySet\">\uff15-\uff12\uff0eCollection.toArray\u3092\u4f7f\u3046\u65b9\u6cd5<span>(Set)<\/span><\/span><\/h3>\n<p>\u30b3\u30ec\u30af\u30b7\u30e7\u30f3\u3068\u3057\u3066\u5024\u3092\u5165\u308c\u3066\u3044\u308b\u578b\u304c<span>Set<\/span>\u3067\u3082\u3084\u308a\u65b9\u306f\u540c\u3058\u3067\u3001<span>List<\/span>\u3068\u540c\u3058\u3088\u3046\u306b<span>toArray()<\/span>\u3092\u4f7f\u3046\u3060\u3051\u3067\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">Set&lt;Integer&gt; set = new HashSet&lt;&gt;();\r\nset.add(1);\r\nset.add(2);\r\nset.add(3);\r\nInteger[] array = set.toArray(new Integer[set.size()]);\r\n\r\nSystem.out.println(java.util.Arrays.toString(array)); \/\/ \u2192 [1, 2, 3]<\/pre>\n<p>\u305f\u3060\u3057\u3001\u914d\u5217\u306b\u3069\u306e\u9806\u756a\u3067\u5165\u308b\u304b\u306f\u8981\u6ce8\u610f\u3067\u3059\u3002\u5b9f\u4f53\u304c<span>HashSet<\/span>\u306a\u3089\u660e\u78ba\u306a\u9806\u5e8f\u306e\u898f\u5247\u306f\u3042\u308a\u307e\u305b\u3093<span>(<\/span>\u3069\u3046\u4e26\u3076\u304b\u5206\u304b\u3089\u306a\u3044<span>)<\/span>\u3002<span>TreeSet<\/span>\u3084<span>LinkedHashSet<\/span>\u306a\u3069\u306e\u4ed6\u306e<span>Set<\/span>\u3067\u306f\u6c7a\u3081\u3089\u308c\u305f\u30eb\u30fc\u30eb\u304c\u3042\u308a\u307e\u3059\u306e\u3067\u3001\u8a73\u7d30\u306f\u5404\u30af\u30e9\u30b9\u306e<span>API<\/span>\u4ed5\u69d8\u3092\u78ba\u8a8d\u3057\u307e\u3057\u3087\u3046\u3002<\/p>\n<h3><span id=\"-CollectiontoArrayMap\">\uff15-\uff13\uff0eCollection.toArray\u3092\u4f7f\u3046(Map)<\/span><\/h3>\n<p>Collection.toArray\u306f\u3001Map\u306b\u683c\u7d0d\u3055\u308c\u3066\u3044\u308b\u30ad\u30fc\u3084\u5024\u3092\u914d\u5217\u3068\u3057\u3066\u53d6\u308a\u51fa\u3057\u305f\u3044\u5834\u5408\u306b\u3082\u4f7f\u3048\u307e\u3059\u3002\u8003\u3048\u65b9\u3068\u3057\u3066\u306fList\u3068Set\u306e\u5834\u5408\u3068\u540c\u3058\u3067\u3001Map\u306e\u30ad\u30fc\u3084\u5024\u3092Set\u3068Collection\u3068\u3057\u3066\u53d6\u308a\u51fa\u3057\u3001\u305d\u308c\u3092\u914d\u5217\u306b\u5909\u63db\u3057\u307e\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">Map&lt;Integer, String&gt; map = new HashMap&lt;&gt;();\r\nmap.put(1, \"\u4e00\");\r\nmap.put(2, \"\u4e8c\");\r\nmap.put(3, \"\u4e09\");\r\n\r\nSet&lt;Integer&gt; keySet = map.keySet(); \/\/ Map\u304b\u3089\u30ad\u30fc\u3092Set\u3068\u3057\u3066\u53d6\u308a\u51fa\u3059\r\nCollection&lt;String&gt; values = map.values(); \/\/ Map\u304b\u3089\u5024\u3092Collection\u3068\u3057\u3066\u53d6\u308a\u51fa\u3059\r\nInteger[] array1 = keySet.toArray(new Integer[keySet.size()]); \/\/ Set\u3092\u914d\u5217\u306b\u5909\u63db\u3059\u308b\r\nString[] array2 = values.toArray(new String[values.size()]); \/\/ Collection\u3092\u914d\u5217\u306b\u5909\u63db\u3059\u308b\r\n\r\nSystem.out.println(java.util.Arrays.toString(array1)); \/\/ \u2192 [1, 2, 3]\r\nSystem.out.println(java.util.Arrays.toString(array2)); \/\/ \u2192 [\u4e00, \u4e8c, \u4e09]<\/pre>\n<h3><span id=\"-StreamtoArray\">\uff15-\uff14\uff0eStream.toArray\u3092\u4f7f\u3046<\/span><\/h3>\n<p>Java 8\u304b\u3089\u4f7f\u3048\u308b\u3088\u3046\u306b\u306a\u3063\u305f<span>Stream API<\/span>\u3092\u4f7f\u3063\u3066\u3082\u540c\u3058\u3088\u3046\u306a\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">List&lt;Integer&gt; list = Arrays.asList(1, 2, 3);\r\nInteger[] array = list.stream().map(i -&gt; i + 10).toArray(Integer[]::new); \/\/ List\u306e\u5404\u8981\u7d20\u306b10\u3092\u8db3\u3057\u3001\u7d50\u679c\u3092Integer\u306e\u914d\u5217\u3068\u3057\u3066\u53d6\u308a\u51fa\u3059\r\n\r\nSystem.out.println(java.util.Arrays.toString(array)); \/\/ \u2192 [11, 12, 13]<\/pre>\n<p>Stream\u3092\u4f7f\u3063\u3066\u3044\u308b\u3068<span>Collection<\/span>\u304c\u4e2d\u5fc3\u3068\u306a\u308b\u306e\u3067\u914d\u5217\u3092\u4f7f\u3046\u30b1\u30fc\u30b9\u306f\u5c11\u306a\u304f\u306a\u308a\u307e\u3059\u3002\u3067\u3082\u3001\u3053\u306e\u3088\u3046\u306b<span>Stream<\/span>\u3067\u51e6\u7406\u3092\u3057\u305f\u7d50\u679c\u3092\u914d\u5217\u3068\u3057\u3066\u53d6\u308a\u51fa\u3059\u3053\u3068\u3082\u3067\u304d\u308b\u306e\u3067\u3001\u899a\u3048\u3066\u304a\u3044\u3066\u3082\u640d\u306f\u3042\u308a\u307e\u305b\u3093\u306d\u3002<\/p>\n<p>\u306a\u304a\u3001\u3053\u306e\u30b5\u30f3\u30d7\u30eb\u306f\u53c2\u7167\u578b\u306e<span>Integer<\/span>\u3092\u4f7f\u3063\u3066\u3044\u307e\u3059\u304c\u3001\u30d7\u30ea\u30df\u30c6\u30a3\u30d6\u578b\u3067\u3042\u308c\u3070\u3044\u3044\u306a\u3089\u3001<span>IntStream<\/span>\u306a\u3069\u3092\u4f7f\u3046\u3068\u3082\u3063\u3068\u304a\u624b\u8efd\u306b\u66f8\u3051\u305f\u308a\u3057\u307e\u3059\u3002<\/p>\n<h2><span id=\"JavaArraysfill\">\uff16\uff0eJava\u914d\u5217\u306e\u521d\u671f\u5316\u2465\uff1aArrays.fill\u3067\u56fa\u5b9a\u5024\u3092\u8a2d\u5b9a\u3059\u308b<\/span><\/h2>\n<p>\u4eca\u307e\u3067\u306e\u65b9\u6cd5\u3067\u306f\u3001\u8a2d\u5b9a\u3057\u305f\u3044\u5024\u3084\u30b3\u30d4\u30fc\u5143\u3068\u306a\u308b\u914d\u5217\u3001\u5024\u3092\u6301\u3063\u3066\u3044\u308b\u30b3\u30ec\u30af\u30b7\u30e7\u30f3\u304c\u65e2\u306b\u3042\u308b\u5834\u5408\u306b\u3064\u3044\u3066\u304a\u4f1d\u3048\u3057\u3066\u304d\u307e\u3057\u305f\u3002\u3067\u3059\u304c\u3001\u5b9f\u969b\u306b\u306f\u5358\u7d14\u306b\u540c\u3058\u5024\u3067\u521d\u671f\u5316\u304c\u3067\u304d\u3055\u3048\u3059\u308c\u3070\u7528\u304c\u6e08\u3080\u5834\u5408\u3082\u3042\u308a\u307e\u3059\u3002<\/p>\n<p>\u305d\u306e\u5834\u5408\u306f<span>Arrays.fill<\/span>\u3092\u4f7f\u3046\u3068\u3001\u540c\u3058\u5024\u3092\u4e00\u5ea6\u306b\u8a2d\u5b9a\u3067\u304d\u307e\u3059\u3002\u5927\u5909\u4fbf\u5229\u3067\u3059\u306d\u3002\u305f\u3060\u3057\u3001Object\u3092\u4f7f\u3046\u5834\u5408\u306f\u5168\u3066\u306e\u8981\u7d20\u304c\u540c\u3058\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u3092\u6307\u3059\u3053\u3068\u306b\u306a\u308a\u307e\u3059\u306e\u3067\u3001\u4f7f\u3044\u9053\u306b\u306f\u6c17\u3092\u4ed8\u3051\u3066\u304f\u3060\u3055\u3044\u3002<\/p>\n<p><span class=\"f-marker-p\">\u30af\u30e9\u30b9\uff1a<\/span><\/p>\n<pre class=\"prettyprint lang:default decode:true\">java.util.Arrays<\/pre>\n<p><span class=\"f-marker-w\">\u30e1\u30bd\u30c3\u30c9\uff1a<\/span><\/p>\n<pre class=\"prettyprint lang:default decode:true\">public static void fill(Object[] a, Object val)\r\npublic static void fill(boolean[] a, boolean val)\r\npublic static void fill(byte[] a, byte val)\r\npublic static void fill(char[] a, char val)\r\npublic static void fill(double[] a, double val)\r\npublic static void fill(float[] a, float val)\r\npublic static void fill(int[] a, int val)\r\npublic static void fill(long[] a, long val)\r\npublic static void fill(short[] a, short val)<\/pre>\n<div class=\"attention a-3\">\n<p class=\"attention-title\" style=\"text-align: left;\">\u5f15\u6570\u306e\u610f\u5473<\/p>\n<ul>\n<li>a &#8211; \u5024\u3092\u4ee3\u5165\u3059\u308b\u914d\u5217<\/li>\n<li>val &#8211; \u914d\u5217\u306e\u3059\u3079\u3066\u306e\u8981\u7d20\u306b\u683c\u7d0d\u3059\u308b\u5024<\/li>\n<\/ul>\n<\/div>\n<pre class=\"prettyprint lang:default decode:true\">int[] array = new int[3];\r\nArrays.fill(array, 10);\r\n\r\nSystem.out.println(java.util.Arrays.toString(array)); \/\/ \u2192 [10, 10, 10]\r\n\r\nObject[] arrayObj = new Object[3];\r\nArrays.fill(arrayObj, new Object());\r\n\r\nSystem.out.println(java.util.Arrays.toString(arrayObj)); \/\/ \u2192 [java.lang.Object@67b64c45, java.lang.Object@67b64c45, java.lang.Object@67b64c45] \u203b\u5168\u3066\u540c\u3058Object\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u6307\u3057\u3066\u3044\u308b<\/pre>\n<p>Arrays.fill\u306f\u3001\u914d\u5217\u306e\u4e00\u90e8\u306e\u7bc4\u56f2\u3060\u3051\u306b\u8a2d\u5b9a\u3067\u304d\u308b\u30aa\u30fc\u30d0\u30fc\u30ed\u30fc\u30c9\u3055\u308c\u305f\u30e1\u30bd\u30c3\u30c9\u304c\u5b58\u5728\u3057\u307e\u3059\u3002\u958b\u59cb\u4f4d\u7f6e\u3068\u3001\u7d42\u4e86\u4f4d\u7f6e\u306e\u4e00\u3064\u5f8c\u3092\u6307\u5b9a\u3057\u307e\u3059\u3002<\/p>\n<p><span class=\"f-marker-p\">\u30af\u30e9\u30b9\uff1a<\/span><\/p>\n<pre class=\"prettyprint lang:default decode:true\">java.util.Arrays<\/pre>\n<p><span class=\"f-marker-w\">\u30e1\u30bd\u30c3\u30c9\uff1a<\/span><\/p>\n<pre class=\"prettyprint lang:default decode:true\">public static void fill(Object[] a, int fromIndex, int toIndex, Object val)\r\npublic static void fill(boolean[] a, int fromIndex, int toIndex, boolean val)\r\npublic static void fill(byte[] a, int fromIndex, int toIndex, byte val)\r\npublic static void fill(char[] a, int fromIndex, int toIndex, char val)\r\npublic static void fill(double[] a, int fromIndex, int toIndex, double val)\r\npublic static void fill(float[] a, int fromIndex, int toIndex, float val)\r\npublic static void fill(int[] a, int fromIndex, int toIndex, int val)\r\npublic static void fill(long[] a, int fromIndex, int toIndex, long val)\r\npublic static void fill(short[] a, int fromIndex, int toIndex, short val)<\/pre>\n<div class=\"attention a-3\">\n<p class=\"attention-title\" style=\"text-align: left;\">\u5f15\u6570\u306e\u610f\u5473<\/p>\n<ul>\n<li>a &#8211; \u5024\u3092\u4ee3\u5165\u3059\u308b\u914d\u5217<\/li>\n<li>fromIndex &#8211; \u6307\u5b9a\u3055\u308c\u305f\u5024\u3092\u4ee3\u5165\u3059\u308b\u6700\u521d\u306e\u8981\u7d20(\u3053\u308c\u3092\u542b\u3080)\u306e\u30a4\u30f3\u30c7\u30c3\u30af\u30b9<\/li>\n<li>toIndex &#8211; \u6307\u5b9a\u3055\u308c\u305f\u5024\u3092\u4ee3\u5165\u3059\u308b\u6700\u5f8c\u306e\u8981\u7d20(\u3053\u308c\u3092\u542b\u307e\u306a\u3044)\u306e\u30a4\u30f3\u30c7\u30c3\u30af\u30b9<\/li>\n<li>val &#8211; \u914d\u5217\u306e\u3059\u3079\u3066\u306e\u8981\u7d20\u306b\u683c\u7d0d\u3059\u308b\u5024<\/li>\n<\/ul>\n<\/div>\n<pre class=\"prettyprint lang:default decode:true\">int[] array = new int[3];\r\nArrays.fill(array, 1, 3, 10); \/\/ \u6dfb\u3048\u5b571\uff5e2\u306b\u3060\u305110\u3092\u8a2d\u5b9a\u3059\u308b\r\n\r\nSystem.out.println(java.util.Arrays.toString(array)); \/\/ \u2192 [0, 10, 10]<\/pre>\n<h2><span id=\"i-8\">\uff17\uff0e\u3055\u3044\u3054\u306b<\/span><\/h2>\n<p>\u3053\u306e\u8a18\u4e8b\u3067\u306f\u914d\u5217\u3092\u521d\u671f\u5316\u3059\u308b\u3068\u3044\u3046\u3088\u308a\u3082\u3001\u4f55\u304b\u3092\u914d\u5217\u306b\u5909\u63db\u3059\u308b\u3068\u3044\u3046\u5185\u5bb9\u304c\u591a\u304f\u306a\u308a\u307e\u3057\u305f\u3002<\/p>\n<p>\u914d\u5217\u306f\u307b\u3068\u3093\u3069\u3059\u3079\u3066\u306e\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u8a00\u8a9e\u3067\u5b58\u5728\u3057\u307e\u3059\u306e\u3067\u3001\u540c\u3058\u3088\u3046\u306a\u3084\u308a\u65b9\u3001\u3042\u308b\u3044\u306f\u7570\u306a\u3063\u305f\u3084\u308a\u65b9\u304c\u4ed6\u306e\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u8a00\u8a9e\u306b\u3082\u3042\u308b\u306f\u305a\u3067\u3059\u3002<\/p>\n<p>\u3053\u306e\u3088\u3046\u306b\u3001\u914d\u5217\u306e\u521d\u671f\u5316\u30fb\u5909\u63db\u306e\u4ed5\u65b9\u306b\u306f\u8272\u3005\u306a\u3084\u308a\u65b9\u304c\u3042\u308a\u307e\u3059\u306e\u3067\u3001\u72b6\u6cc1\u306b\u5fdc\u3058\u3066\u9069\u6750\u9069\u6240\u3067\u4f7f\u3048\u308b\u3088\u3046\u306b\u306a\u308a\u307e\u3057\u3087\u3046<span>!!<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u3067\u306e\u30c7\u30fc\u30bf\u69cb\u9020\u306e\u57fa\u672c\u306f\u914d\u5217\u3067\u3059\u3002\u914d\u5217\u3092\u4f7f\u3046\u969b\u306f\u3001\u4f55\u304b\u3057\u3089\u306e\u521d\u671f\u5024\u3092\u8a2d\u5b9a\u3057\u305f\u3044\u3067\u3059\u3088\u306d\u3002 \u307e\u305f\u3001\u4f55\u304b\u5225\u306e\u30c7\u30fc\u30bf\u304b\u3089\u914d\u5217\u3092\u4f5c\u308a\u305f\u3044\u3053\u3068\u3082\u3042\u308b\u3067\u3057\u3087\u3046\u3002\u3053\u306e\u914d\u5217\u306e\u521d\u671f\u5316\u306b\u306f\u3001\u5927\u304d\u304f\u5206\u3051\u3066\u4ee5\u4e0b\u306e\u65b9\u6cd5\u304c\u3042\u308a\u307e\u3059(Ja [&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\/776"}],"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=776"}],"version-history":[{"count":14,"href":"https:\/\/www.bold.ne.jp\/engineer-club\/wp-json\/wp\/v2\/posts\/776\/revisions"}],"predecessor-version":[{"id":5676,"href":"https:\/\/www.bold.ne.jp\/engineer-club\/wp-json\/wp\/v2\/posts\/776\/revisions\/5676"}],"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=776"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bold.ne.jp\/engineer-club\/wp-json\/wp\/v2\/categories?post=776"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}