{"id":1375,"date":"2019-02-12T20:30:44","date_gmt":"2019-02-12T11:30:44","guid":{"rendered":"https:\/\/www.bold.ne.jp\/engineer-club\/?p=1375"},"modified":"2025-10-06T17:00:49","modified_gmt":"2025-10-06T08:00:49","slug":"java-equals","status":"publish","type":"post","link":"https:\/\/www.bold.ne.jp\/engineer-club\/java-equals","title":{"rendered":"java equals\u3068\u306f\uff1fjava equals\u3092\u901a\u3058\u3066\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u304c\u300c\u540c\u3058\u300d\u304b\u30c1\u30a7\u30c3\u30af\u3057\u3088\u3046"},"content":{"rendered":"<p><strong>Java\u306eObject\u30af\u30e9\u30b9\u306b\u3042\u308b\u30e1\u30bd\u30c3\u30c9equals\u306f\u3001\u4f55\u304b\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u540c\u58eb\u304c\u300c\u540c\u3058\u300d\u304b\u3092\u8abf\u3079\u308b\u30e1\u30bd\u30c3\u30c9\u3067\u3059\u3002<\/strong><\/p>\n<p>\u3053\u3053\u3067\u8a00\u3046\u300c\u540c\u3058\u300d\u306b\u3064\u3044\u3066\u3001\u610f\u5473\u3068\u3057\u3066\u540c\u3058\u304b\u3001\u5b9f\u4f53\u3068\u3057\u3066\u540c\u3058\u304b\u306e\u533a\u5225\u304c<span>Java<\/span>\u3067\u306f\u3055\u308c\u308b\u306e\u3067\u3059\u3002\u305d\u3057\u3066\u3001<span>Java<\/span>\u3067\u306f\u305d\u306e\u9055\u3044\u304c\u5b9f\u306b\u91cd\u8981\u3067\u3059\u3002\u305d\u306e\u9055\u3044\u3092\u610f\u8b58\u3067\u304d\u3066\u3044\u308b\u304b\u3067\u3001<span>Java<\/span>\u306e\u30d7\u30ed\u30b0\u30e9\u30e0\u304c\u6b63\u3057\u304f\u52d5\u304f\u304b\u3069\u3046\u304b\u304c\u6c7a\u307e\u3063\u3066\u3057\u307e\u3046\u307b\u3069\u306e\u3082\u306e\u306a\u306e\u3067\u3059\u3002<\/p>\n<p>\u3053\u306e\u6642\u70b9\u3067\u3001\u79c1\u304c\u4f55\u3092\u8a00\u308f\u3093\u3068\u3057\u3066\u3044\u308b\u306e\u304b\u6b63\u76f4\u3088\u304f\u308f\u304b\u3089\u306a\u3044\u3001\u305d\u3046\u3044\u3046\u3053\u3068\u3092\u8003\u3048\u305f\u3053\u3068\u3082\u306a\u304b\u3063\u305f\u304b\u3089\u3061\u3087\u3063\u3068\u4e0d\u5b89\u3060\u306a<span>\u2026<\/span>\u3068\u3044\u3046\u65b9\u3082\u3054\u5b89\u5fc3\u304f\u3060\u3055\u3044\u3002<\/p>\n<p>\u3053\u306e\u8a18\u4e8b\u3067\u306f\u3001\u305d\u3082\u305d\u3082\u540c\u3058\u3068\u306f\u4f55\u305e\u3084\u3068\u3044\u3046\u3068\u3053\u308d\u304b\u3089\u30b9\u30bf\u30fc\u30c8\u3057\u3066\u3001<span>Objet.equals<\/span>\u306e\u5177\u4f53\u7684\u306a\u4f8b\u3068\u3053\u3053\u306f\u62bc\u3055\u3048\u3066\u304a\u304d\u305f\u3044<span>!!<\/span>\u3068\u3044\u3046\u30dd\u30a4\u30f3\u30c8\u307e\u3067\u3001\u5206\u304b\u308a\u3084\u3059\u304f\u304a\u4f1d\u3048\u3057\u307e\u3059\u3002<\/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=\"#Javaequals\">\uff11\uff0e\u3010Java\u3011equals\u306f\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u306e\u300c\u610f\u5473\u300d\u304c\u540c\u3058\u304b\u8abf\u3079\u308b\u3082\u306e<\/a><ul><li><a href=\"#i\">\uff11-\uff11\uff0e\u300c\u540c\u3058\u300d\u3067\u3042\u308b\u3068\u306f\u3069\u3046\u3044\u3046\u3053\u3068\u304b<\/a><\/li><li><a href=\"#i-2\">\uff11-\uff12\uff0e\u610f\u5473\u4e0a\u3067\u306e\u540c\u3058\u3068\u3001\u5b9f\u4f53\u304c\u540c\u3058\u306e\u9055\u3044<\/a><\/li><li><a href=\"#-equalsString\">\uff11-\uff13\uff0eequals\u3068==\u306e\u9055\u3044\u3092String\u3067\u4f53\u9a13\u3057\u3088\u3046<\/a><\/li><li><a href=\"#i-3\">\uff11-\uff14\uff0e\u610f\u5473\u7684\u306b\u540c\u3058\u3068\u306f\u3001\u6301\u3063\u3066\u3044\u308b\u60c5\u5831\u304c\u540c\u3058\u3068\u3044\u3046\u3053\u3068<\/a><\/li><\/ul><\/li><li><a href=\"#JavaObjectequals\">\uff12\uff0e\u3010Java\u3011Object.equals\u306e\u4f7f\u3044\u65b9<\/a><ul><li><a href=\"#-equals\">\uff12-\uff11\uff0eequals\u3068\u306f\u610f\u5473\u7684\u306b\u540c\u3058\u304b\u78ba\u8a8d\u3059\u308b\u3082\u306e<\/a><\/li><li><a href=\"#-equals-2\">\uff12-\uff12\uff0eequals\u306f\u30b5\u30d6\u30af\u30e9\u30b9\u3067\u30aa\u30fc\u30d0\u30fc\u30e9\u30a4\u30c9\u3059\u308b<\/a><\/li><li><a href=\"#-equals4\">\uff12-\uff13\uff0eequals\u3067\u30c1\u30a7\u30c3\u30af\u3059\u3079\u304d4\u3064\u306e\u30dd\u30a4\u30f3\u30c8<\/a><\/li><li><a href=\"#i-4\">\uff12-\uff14\uff0e\u30d5\u30a3\u30fc\u30eb\u30c9\u306e\u578b\u3054\u3068\u306e\u6bd4\u8f03\u306e\u4ed5\u65b9<\/a><\/li><\/ul><\/li><li><a href=\"#equals\">\uff13\uff0e\u3010\u767a\u5c55\u3011equals\u3067\u306f\u3069\u3053\u307e\u3067\u30c1\u30a7\u30c3\u30af\u3059\u3079\u304d\u304b?<\/a><ul><li><a href=\"#i-5\">\uff13-\uff11\uff0e\u540c\u3058\u304b\u3069\u3046\u304b\u306e\u5224\u65ad\u306b\u4f7f\u3046\u5fc5\u8981\u306a\u7bc4\u56f2\u3060\u3051\u3068\u3059\u308b<\/a><\/li><li><a href=\"#-equals-3\">\uff13-\uff12\uff0e\u8907\u6570\u306e\u6bd4\u8f03\u30ed\u30b8\u30c3\u30af\u304c\u3042\u308b\u306a\u3089\u3001equals\u3068\u306f\u5225\u306e\u30e1\u30bd\u30c3\u30c9\u3092\u4f5c\u308b<\/a><\/li><li><a href=\"#-equals-4\">\uff13-\uff13\uff0eequals\u306e\u30aa\u30fc\u30d0\u30fc\u30ed\u30fc\u30c9\u306f\u3057\u306a\u3044<\/a><\/li><\/ul><\/li><li><a href=\"#equals-2\">\uff14\uff0e\u3010\u767a\u5c55\u3011equals\u306b\u95a2\u3059\u308b\u3042\u308c\u3053\u308c<\/a><ul><li><a href=\"#i-6\">\uff14-\uff11\uff0e\u300c\u9055\u3046\u304b\u300d\u3092\u8abf\u3079\u308b\u306a\u3089\u5426\u5b9a\u6f14\u7b97\u5b50\u3092\u4f7f\u3046<\/a><\/li><li><a href=\"#-ComparableComparatorequals\">\uff14-\uff12\uff0eComparable\/Comparator\u3068equals<\/a><\/li><li><a href=\"#-ObjecthashCodeequals\">\uff14-\uff13\uff0eObject.hashCode\u3068equals<\/a><\/li><li><a href=\"#-equals-5\">\uff14-\uff14\uff0eequals\u3092\u81ea\u52d5\u751f\u6210\u3057\u3066\u697d\u3092\u3059\u308b<\/a><\/li><\/ul><\/li><li><a href=\"#i-7\">\uff15\uff0e\u307e\u3068\u3081<\/a><\/li><\/ul><\/div>\n<h2><span id=\"Javaequals\">\uff11\uff0e\u3010Java\u3011equals\u306f\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u306e\u300c\u610f\u5473\u300d\u304c\u540c\u3058\u304b\u8abf\u3079\u308b\u3082\u306e<\/span><\/h2>\n<h3><span id=\"i\">\uff11-\uff11\uff0e\u300c\u540c\u3058\u300d\u3067\u3042\u308b\u3068\u306f\u3069\u3046\u3044\u3046\u3053\u3068\u304b<\/span><\/h3>\n<p>\u300c\u540c\u3058\u300d\u3067\u3042\u308b\u3068\u306f\u3001\u306f\u305f\u3057\u3066\u3069\u3046\u3044\u3046\u3053\u3068\u304b\u3002\u306a\u304b\u306a\u304b\u54f2\u5b66\u3058\u307f\u305f\u554f\u3044\u304b\u3051\u3067\u3059\u304c\u3001\u3042\u3089\u305f\u3081\u3066\u8003\u3048\u3066\u307f\u308b\u3068\u3061\u3087\u3063\u3068\u9762\u5012\u306a\u3082\u306e\u3067\u3059\u3002<\/p>\n<p>\u4f8b\u3048\u3070\u3001\u58ca\u308c\u3066\u4fee\u7406\u306b\u51fa\u3057\u305f\u30b9\u30de\u30db\u304c\u623b\u3063\u3066\u304d\u305f\u3068\u3057\u307e\u3059\u3002\u30b9\u30de\u30db\u305d\u306e\u3082\u306e\u306f\u4ea4\u63db\u3055\u308c\u3066\u65b0\u54c1\u306b\u306a\u308a\u307e\u3057\u305f\u3002\u3067\u3082\u3001\u53e4\u3044\u30b9\u30de\u30db\u306e\u4e2d\u306b\u3042\u3063\u305f\u5199\u771f\u3084\u30c6\u30ad\u30b9\u30c8\u3001\u30e6\u30fc\u30b6\u60c5\u5831\u3084\u30c7\u30fc\u30bf\u306f\u3001\u30b5\u30dd\u30fc\u30c8\u304c\u65b0\u3057\u3044\u30b9\u30de\u30db\u306b\u5168\u90e8\u305d\u306e\u307e\u307e\u30b3\u30d4\u30fc\u3057\u3066\u304f\u308c\u307e\u3057\u305f\u3002\u3067\u3059\u304b\u3089\u3001\u30b9\u30de\u30db\u306f\u4fee\u7406\u306b\u51fa\u3059\u524d\u3068\u307e\u3063\u305f\u304f\u540c\u3058\u3088\u3046\u306b\u4f7f\u3048\u307e\u3059\u3002<\/p>\n<p>\u3055\u3066\u3001\u3053\u3053\u3067\u53e4\u3044\u30b9\u30de\u30db\u3068\u65b0\u3057\u3044\u30b9\u30de\u30db\u306f\u300c\u540c\u3058\u3082\u306e\u300d\u3060\u3068\u8a00\u3048\u308b\u3067\u3057\u3087\u3046\u304b\u3002<br \/>\n\u5b9f\u306f\u3001\u305d\u308c\u306f\u8003\u3048\u65b9\u6b21\u7b2c\u3067\u3059\u3002\u4e21\u65b9\u3068\u3082\u540c\u3058\u30c7\u30fc\u30bf\u3092\u6301\u3063\u3066\u3044\u3066\u540c\u3058\u3088\u3046\u306b\u4f7f\u3048\u308b\u306e\u3067\u3059\u304b\u3089\u3001\u4f7f\u3044\u52dd\u624b\u3068\u3057\u3066\u306f\u540c\u3058\u3082\u306e\u3060\u3068\u8a00\u3048\u308b\u3067\u3057\u3087\u3046\u3002\u3067\u3082\u3001\u540c\u3058\u6a5f\u7a2e\u3067\u3082\u30cf\u30fc\u30c9\u30a6\u30a7\u30a2\u304c\u9055\u3046\u306e\u3060\u304b\u3089\u540c\u3058\u3082\u306e\u3067\u306f\u306a\u3044\u3001\u3068\u3082\u8a00\u3048\u307e\u3059\u3002<\/p>\n<h3><span id=\"i-2\">\uff11-\uff12\uff0e\u610f\u5473\u4e0a\u3067\u306e\u540c\u3058\u3068\u3001\u5b9f\u4f53\u304c\u540c\u3058\u306e\u9055\u3044<\/span><\/h3>\n<p>\u524d\u7bc0\u3067\u306e\u8003\u3048\u65b9\u306e\u5dee\u306f\u3001\u610f\u5473\u3068\u3057\u3066\u540c\u3058\u3067\u3042\u308b\u304b\u3068\u3001\u5b9f\u4f53\u3068\u3057\u3066\u540c\u3058\u3067\u3042\u308b\u304b\u306e\u5dee\u3067\u3059\u3002\u3053\u306e\u5dee\u306f\u3001<span>Java<\/span>\u3067\u3082\u300c\u540c\u3058\u300d\u304b\u5224\u65ad\u3092\u3059\u308b\u6642\u306b\u306f\u3001\u540c\u69d8\u306a\u3053\u3068\u304c\u8a00\u3048\u307e\u3059\u3002<\/p>\n<p>\u3064\u307e\u308a\u3001\u30af\u30e9\u30b9\u304b\u3089\u4f5c\u3089\u308c\u305f\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u304c\u540c\u3058\u3067\u3042\u308b\u304b\u8abf\u3079\u308b\u6642\u3067\u3082\u3001\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u304c\u6301\u3064\u610f\u5473\u3068\u3057\u3066\u540c\u3058\u3067\u3042\u308b\u5834\u5408\u3068\u3001\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u306e\u5b9f\u4f53\u3068\u3057\u3066\u540c\u3058\u3067\u3042\u308b\u5834\u5408\u306e\u4e8c\u7a2e\u985e\u304c\u3042\u308b\u306e\u3067\u3059\u3002<\/p>\n<p>Java\u3067\u3001\u610f\u5473\u3068\u3057\u3066\u540c\u3058\u304b\u3092\u8abf\u3079\u308b\u306e\u304c\u3001\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u30e1\u30bd\u30c3\u30c9<span>Object.equals<\/span>\u3067\u3059\u3002\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u306e\u5b9f\u4f53\u3068\u3057\u3066\u540c\u3058\u304b\u3092\u8abf\u3079\u308b\u306e\u304c\u3001\u6bd4\u8f03\u6f14\u7b97\u5b50<span>==<\/span>\u3067\u3059\u3002<\/p>\n<h3><span id=\"-equalsString\">\uff11-\uff13\uff0eequals\u3068<span>==<\/span>\u306e\u9055\u3044\u3092<span>String<\/span>\u3067\u4f53\u9a13\u3057\u3088\u3046<\/span><\/h3>\n<p>equals\u3068<span>==<\/span>\u306e\u9055\u3044\u304c\u5206\u304b\u308a\u3084\u3059\u3044\u306e\u306f\u6587\u5b57\u5217\u3001\u3059\u306a\u308f\u3061<span>String<\/span>\u3067\u3059\u3002\u4ee5\u4e0b\u306e\u30d7\u30ed\u30b0\u30e9\u30e0\u3092\u8aad\u3093\u3067\u307f\u3066\u3001\u305d\u3057\u3066\u305c\u3072\u5b9f\u884c\u3057\u3066\u307f\u3066\u304f\u3060\u3055\u3044\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">String str1 = \"ABCD\";\r\nString str2 = new String(new byte[] { 0x41, 0x42, 0x43, 0x44 }); \/\/ \u6570\u5024\u3067\u306e\u8868\u73fe\u3060\u304c\u3001\"ABCD\"\u3068\u540c\u3058\u610f\u5473\r\n\r\n\/\/ \u4e8c\u3064\u306eString\u304c\u6301\u3064\u6587\u5b57\u5217\u306f\u898b\u305f\u76ee\u4e0a\u3067\u306f\u540c\u3058\r\nSystem.out.println(str1); \/\/ \u2192 ABCD\r\nSystem.out.println(str2); \/\/ \u2192 ABCD\r\n\r\n\/\/ \u4e8c\u3064\u306eString\u304c\u6301\u3064\u6587\u5b57\u5217\u304c\u540c\u3058\u304bequals\u3067\u78ba\u8a8d\u3059\u308b\r\nif (str1.equals(str2)) {\r\n\tSystem.out.println(\"str1 \u3068 str2 \u306f\u540c\u3058\u6587\u5b57\u5217\u3067\u3059\u3002\"); \/\/ \u3053\u3061\u3089!!\r\n} else {\r\n\tSystem.out.println(\"str1 \u3068 str2 \u306f\u9055\u3046\u6587\u5b57\u5217\u3067\u3059\u3002\");\r\n}\r\n\r\n\/\/ \u4e8c\u3064\u306eString\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u304c\u540c\u3058\u304b==\u3067\u78ba\u8a8d\u3059\u308b\r\nif (str1 == str2) {\r\n\tSystem.out.println(\"str1 \u3068 str2 \u306f\u540c\u3058\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3067\u3059\u3002\");\r\n} else {\r\n\tSystem.out.println(\"str1 \u3068 str2 \u306f\u9055\u3046\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3067\u3059\u3002\"); \/\/ \u3053\u3061\u3089!!\r\n}<\/pre>\n<p>\u5909\u6570<span>str1<\/span>\u3068<span>str2<\/span>\u306f\u3001\u4e21\u65b9\u3068\u3082<span>&#8220;ABCD&#8221;<\/span>\u3068\u3044\u3046\u6587\u5b57\u5217\u3092\u6301\u3064<span>String<\/span>\u3092\u6307\u3057\u3066\u3044\u307e\u3059\u3002\u524d\u8005\u306e<span>String<\/span>\u306f\u6587\u5b57\u5217\u30ea\u30c6\u30e9\u30eb\u3067\u4f5c\u308a\u3001\u5f8c\u8005\u306e<span>String<\/span>\u306f<span>String<\/span>\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092<span>byte<\/span>\u914d\u5217\u304b\u3089\u65b0\u3057\u304f\u4f5c\u3063\u3066\u3044\u307e\u3059\u3002<\/p>\n<p>\u3053\u306e\u4e8c\u3064\u306e<span>String<\/span>\u306f\u3001\u305d\u308c\u305e\u308c\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u304c\u305d\u306e\u5185\u90e8\u306b\u6301\u3063\u3066\u3044\u308b\u6587\u5b57\u5217\u3001\u3059\u306a\u308f\u3061\u5024\u306f\u540c\u3058\u3067\u3059\u3002\u3067\u3059\u304b\u3089\u3001<span>str1<\/span>\u3068<span>str2<\/span>\u304c\u6307\u3059<span>String<\/span>\u540c\u58eb\u3092<span>equals<\/span>\u3067\u6bd4\u3079\u308b\u3068\u3001\u540c\u3058\u3068\u3044\u3046\u7b54\u3048\u304c\u8fd4\u3063\u3066\u304d\u307e\u3059\u3002<\/p>\n<p>\u3057\u304b\u3057\u3001<span>String<\/span>\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3068\u3057\u3066\u306f\u5225\u7269\u3067\u3059\u3002<span>str2<\/span>\u304c\u6307\u3059<span>String<\/span>\u306f\u65b0\u3057\u304f\u4f5c\u3063\u3066\u3044\u307e\u3059\u304b\u3089\u3001<span>Java<\/span>\u306e\u30e1\u30e2\u30ea\u4e0a\u306b\u306f\u3001\u4e8c\u3064\u306e<span>String<\/span>\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u304c\u305d\u308c\u305e\u308c\u9055\u3046\u5b9f\u4f53\u3068\u3057\u3066\u3042\u308b\u306e\u3067\u3059\u3002\u3060\u304b\u3089\u3001<span>str1<\/span>\u3068<span>str2<\/span>\u3092<span>==<\/span>\u3067\u6bd4\u3079\u308b\u3068\u3001\u9055\u3046\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u6307\u3057\u3066\u3044\u308b\u3068\u3044\u3046\u7b54\u3048\u304c\u8fd4\u3063\u3066\u304d\u307e\u3059\u3002<\/p>\n<h3><span id=\"i-3\">\uff11-\uff14\uff0e\u610f\u5473\u7684\u306b\u540c\u3058\u3068\u306f\u3001\u6301\u3063\u3066\u3044\u308b\u60c5\u5831\u304c\u540c\u3058\u3068\u3044\u3046\u3053\u3068<\/span><\/h3>\n<p>\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u540c\u58eb\u304c\u610f\u5473\u7684\u306b\u540c\u3058\u3067\u3042\u308b\u3068\u306f\u3001\u5177\u4f53\u7684\u306b\u306f\u3069\u3046\u3044\u3046\u3053\u3068\u306a\u306e\u3067\u3057\u3087\u3046\u304b\u3002\u666e\u901a\u306f\u3001\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u304c\u6301\u3064\u30c7\u30fc\u30bf\u304c\u540c\u3058\u3067\u3042\u308c\u3070\u3001\u610f\u5473\u7684\u306b\u540c\u3058\u3068\u3057\u307e\u3059\u3002\u30af\u30e9\u30b9\u3068\u306f\u30c7\u30fc\u30bf<span>(=<\/span>\u30d5\u30a3\u30fc\u30eb\u30c9\u3001\u30e1\u30f3\u30d0\u5909\u6570<span>)<\/span>\u3068\u624b\u7d9a\u304d<span>(=<\/span>\u30e1\u30bd\u30c3\u30c9<span>)<\/span>\u304c\u4e00\u3064\u306b\u306a\u3063\u305f\u3082\u306e\u3067\u3059\u304c\u3001\u305d\u306e\u30c7\u30fc\u30bf\u304c\u540c\u3058\u304b\u3069\u3046\u304b\u3067\u3059\u3002<\/p>\n<p>\u306a\u305c\u304b\u3068\u8a00\u3046\u3068\u3001\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u7279\u5fb4\u3065\u3051\u308b\u306e\u306f\u6301\u3063\u3066\u3044\u308b\u30c7\u30fc\u30bf\u3060\u304b\u3089\u3067\u3059\u3002\u3069\u3046\u3044\u3046\u7d4c\u7def\u3067\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u304c\u4f5c\u3089\u308c\u3088\u3046\u3068\u3001\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u304c\u6301\u3063\u3066\u3044\u308b\u30c7\u30fc\u30bf\u304c\u540c\u3058\u306a\u3089\u3001\u30e1\u30bd\u30c3\u30c9\u3092\u547c\u3093\u3060\u6642\u306e\u632f\u308b\u821e\u3044\u306f\u540c\u3058\u306b\u306a\u308a\u307e\u3059\u3002\u3060\u304b\u3089\u3001\u540c\u3058\u30c7\u30fc\u30bf\u3092\u6301\u3064\u306a\u3089\u3070\u3001\u540c\u3058\u3068\u898b\u306a\u305d\u3046\u3068\u3044\u3046\u3053\u3068\u306b\u3057\u3066\u3044\u308b\u306e\u3067\u3059\u3002<\/p>\n<h2><span id=\"JavaObjectequals\">\uff12\uff0e\u3010Java\u3011Object.equals\u306e\u4f7f\u3044\u65b9<\/span><\/h2>\n<h3><span id=\"-equals\">\uff12-\uff11\uff0eequals\u3068\u306f\u610f\u5473\u7684\u306b\u540c\u3058\u304b\u78ba\u8a8d\u3059\u308b\u3082\u306e<\/span><\/h3>\n<p>Object.equals\u306f\u3001\u3059\u3079\u3066\u306e\u30af\u30e9\u30b9\u306e\u30b9\u30fc\u30d1\u30fc\u30af\u30e9\u30b9\u3067\u3042\u308b<span>Object<\/span>\u304c\u6301\u3064\u3001\u81ea\u5206\u81ea\u8eab\u3068\u5f15\u6570\u306e\u4f55\u304b\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u304c\u610f\u5473\u7684\u306b\u540c\u3058\u304b\u8abf\u3079\u308b\u30e1\u30bd\u30c3\u30c9\u3067\u3059\u3002<span>true<\/span>\u3092\u623b\u305b\u3070\u540c\u3058\u3001<span>false<\/span>\u3092\u623b\u305b\u3070\u540c\u3058\u3067\u306f\u306a\u3044\u3001\u3068\u3044\u3046\u3053\u3068\u3067\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">public boolean equals(Object obj)\r\n\u30d1\u30e9\u30e1\u30fc\u30bf:\r\n\tobj - \u6bd4\u8f03\u5bfe\u8c61\u306e\u53c2\u7167\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u3002\r\n\u623b\u308a\u5024:\r\n\t\u3053\u306e\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u304cobj\u5f15\u6570\u3068\u540c\u3058\u3067\u3042\u308b\u5834\u5408\u306ftrue\u3001\u305d\u308c\u4ee5\u5916\u306e\u5834\u5408\u306ffalse\u3002<\/pre>\n<p>Object.equals\u306f\u62bd\u8c61\u30e1\u30bd\u30c3\u30c9\u3067\u306f\u306a\u3044\u306e\u3067\u3001<span>Object<\/span>\u3067\u306e\u30c7\u30d5\u30a9\u30eb\u30c8\u5b9f\u88c5\u304c\u3042\u308a\u307e\u3059\u3002<span>Java 11<\/span>\u3067\u306e\u5b9f\u88c5\u306f\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u306a\u3063\u3066\u3044\u307e\u3059\u3002\u3064\u307e\u308a\u3001\u81ea\u5206\u81ea\u8eab\u3068\u3001\u5f15\u6570\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u306e\u5b9f\u4f53\u304c\u540c\u3058\u304b\u3069\u3046\u304b\u3092\u78ba\u8a8d\u3057\u3066\u3044\u307e\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">\/\/ Java 11\u306e\u30bd\u30fc\u30b9\u30b3\u30fc\u30c9\u3088\u308a\u629c\u7c8b\r\n    public boolean equals(Object obj) {\r\n        return (this == obj);\r\n    }<\/pre>\n<p>\u4eee\u306b\u30af\u30e9\u30b9\u304c\u30c7\u30fc\u30bf\u3092\u6301\u305f\u306a\u3044\u306e\u306a\u3089\u3001\u540c\u3058\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u304b\u3069\u3046\u304b\u3092\u5224\u65ad\u3059\u308b\u65b9\u6cd5\u306f\u3001\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3068\u3057\u3066\u306e\u5b9f\u4f53\u304c\u540c\u3058\u304b\u3069\u3046\u304b\u3057\u304b\u306a\u3044<span>\u2026<\/span>\u3068\u3044\u3046\u3053\u3068\u3067\u3059\u3002<span>Object<\/span>\u3067\u306e\u30c7\u30d5\u30a9\u30eb\u30c8\u5b9f\u88c5\u306f\u305d\u3046\u3044\u3046\u610f\u5473\u306a\u306e\u3067\u3059\u3002<\/p>\n<h4>\uff12-\uff12-\uff11\uff0eequals\u306f\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u306b\u540c\u3058\u304b\u3092\u300c\u805e\u304f\u300d\u30e1\u30bd\u30c3\u30c9<\/h4>\n<p>Object.equals\u304c\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u30e1\u30bd\u30c3\u30c9\u3067\u3042\u308b\u3053\u3068\u306f\u3068\u3066\u3082\u5370\u8c61\u7684\u3067\u3059\u3002\u306a\u305c\u306a\u3089\u300c\u3042\u306a\u305f\u306f\u3053\u308c\u3068\u300e\u540c\u3058\u300f\u3067\u3059\u304b<span>?<\/span>\u300d\u3068\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u306b\u300c\u805e\u304f\u300d\u30e1\u30bd\u30c3\u30c9\u3067\u3042\u308b\u304b\u3089\u3067\u3001\u307e\u3055\u306b\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u6307\u5411\u7684\u306a\u30a2\u30d7\u30ed\u30fc\u30c1\u3067\u3059\u3002<\/p>\n<p>\u9006\u306b\u3001<span>int<\/span>\u3084<span>boolean<\/span>\u306a\u3069\u306e\u30d7\u30ea\u30df\u30c6\u30a3\u30d6\u578b\u306f\u3001<span>Java<\/span>\u3067\u306f\u30af\u30e9\u30b9\u304b\u3089\u4f5c\u3089\u308c\u305f\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3067\u306f\u306a\u304f\u3001\u5024\u305d\u306e\u3082\u306e\u3067\u3059\u3002\u3069\u3093\u306a\u72b6\u6cc1\u3067\u3042\u308d\u3046\u3068\u3001<span>1<\/span>\u306a\u3089\u3059\u3079\u3066\u540c\u3058<span>1<\/span>\u3067\u3001<span>true<\/span>\u306a\u3089\u3059\u3079\u3066\u540c\u3058<span>true<\/span>\u3067\u3059\u3002\u3060\u304b\u3089\u3001\u3053\u308c\u3089\u306e\u5024\u306b\u300c\u540c\u3058\u3067\u3059\u304b<span>?<\/span>\u300d\u3068\u308f\u3056\u308f\u3056\u805e\u304f\u5fc5\u8981\u306f\u306a\u304f\u3001\u3044\u3064\u3067\u3082<span>==<\/span>\u3067\u5024\u3068\u3057\u3066\u306e\u6bd4\u8f03\u304c\u3067\u304d\u308b\u306e\u3067\u3059\u3002<\/p>\n<h3><span id=\"-equals-2\">\uff12-\uff12\uff0eequals\u306f\u30b5\u30d6\u30af\u30e9\u30b9\u3067\u30aa\u30fc\u30d0\u30fc\u30e9\u30a4\u30c9\u3059\u308b<\/span><\/h3>\n<p>\u3069\u3093\u306a\u30af\u30e9\u30b9\u3067\u3082\u5fc5\u305a<span>Object<\/span>\u306e\u30b5\u30d6\u30af\u30e9\u30b9\u3067\u3059\u304b\u3089\u3001\u5fc5\u305a<span>equals<\/span>\u3092\u547c\u3073\u51fa\u305b\u307e\u3059\u3002\u3067\u3082\u3001\u30b5\u30d6\u30af\u30e9\u30b9\u3067\u30aa\u30fc\u30d0\u30fc\u30e9\u30a4\u30c9\u3057\u306a\u3051\u308c\u3070\u3001\u524d\u8ff0\u3057\u305f<span>Object<\/span>\u3067\u306e\u30c7\u30d5\u30a9\u30eb\u30c8\u51e6\u7406\u304c\u4f7f\u308f\u308c\u307e\u3059\u306e\u3067\u3001\u5b9f\u4f53\u304c\u540c\u3058\u304b\u3069\u3046\u304b\u3057\u304b\u308f\u304b\u308a\u307e\u305b\u3093\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">class EqualsSample1 {\r\n\tint id; \/\/ \u30d5\u30a3\u30fc\u30eb\u30c9\u306f\u3042\u308b\u304c\u3001\u540c\u3058\u304b\u3069\u3046\u304b\u306e\u5224\u5b9a\u51e6\u7406\u306b\u306f\u4f7f\u308f\u308c\u3066\u3044\u306a\u3044\u2026\r\n\r\n\tEqualsSample1(int id) {\r\n\t\tthis.id = id;\r\n\t}\r\n\r\n\tpublic static void main(String[] args) {\r\n\t\tEqualsSample1 sample1 = new EqualsSample1();\r\n\t\tEqualsSample1 sample2 = new EqualsSample1();\r\n\r\n\t\tSystem.out.println(sample1.equals(sample2)); \/\/ \u2192 false\r\n\t\tSystem.out.println(sample1 == sample2); \/\/ \u2192 false\r\n\t}\r\n}<\/pre>\n<p>\u3055\u3059\u304c\u306b\u3053\u308c\u3067\u306f\u610f\u5473\u304c\u306a\u3044\u306e\u3067\u3001\u666e\u901a\u306f\u30b5\u30d6\u30af\u30e9\u30b9\u3067<span>equals<\/span>\u3092\u30aa\u30fc\u30d0\u30fc\u30e9\u30a4\u30c9\u3057\u3066\u3001\u5f15\u6570\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u304c\u6301\u3064\u30d5\u30a3\u30fc\u30eb\u30c9\u306e\u5024\u3092\u30c1\u30a7\u30c3\u30af\u3057\u307e\u3059\u3002\u4ee5\u4e0b\u304c\u3001<span>equals<\/span>\u3092\u30aa\u30fc\u30d0\u30fc\u30e9\u30a4\u30c9\u3057\u305f\u4f8b\u3067\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">class EqualsSample2 {\r\n\tint id;\r\n\r\n\tEqualsSample2(int id) {\r\n\t\tthis.id = id;\r\n\t}\r\n\t\r\n\tpublic boolean equals(Object obj) {\r\n\t\t\/\/ EqualsSample2\u306b\u30ad\u30e3\u30b9\u30c8\u3057\u3066\u3001id\u306e\u5024\u304c\u540c\u3058\u304b\u8abf\u3079\u308b\r\n\t\treturn id == ((EqualsSample2)obj).id;\r\n\t}\r\n\r\n\tpublic static void main(String[] args) {\r\n\t\tEqualsSample2 sample1 = new EqualsSample2(1);\r\n\t\tEqualsSample2 sample2 = new EqualsSample2(100);\r\n\t\tEqualsSample2 sample3 = new EqualsSample2(1);\r\n\r\n\t\tSystem.out.println(sample1.equals(sample2)); \/\/ \u2192 false\r\n\t\tSystem.out.println(sample1.equals(sample3)); \/\/ \u2192 true!!\r\n\r\n\t\tSystem.out.println(sample1 == sample2); \/\/ \u2192 false\r\n\t\tSystem.out.println(sample1 == sample3); \/\/ \u2192 false\r\n\t}\r\n}<\/pre>\n<p>\u3053\u306e\u4f8b\u3067\u306f\u3001\u30d5\u30a3\u30fc\u30eb\u30c9\u306e<span>int id<\/span>\u304c\u540c\u3058\u304b\u3069\u3046\u304b\u3092\u898b\u3066\u3044\u307e\u3059\u3002\u3067\u3059\u306e\u3067\u3001\u5f15\u6570\u304c\u540c\u3058\u6570\u5b57\u3067\u3042\u308b<span>sample1<\/span>\u3068<span>sample3<\/span>\u304c\u540c\u3058\u3067\u3042\u308b\u3068<span>equals<\/span>\u3067\u306f\u5224\u65ad\u3055\u308c\u3066\u3044\u307e\u3059\u3002\u3082\u3061\u308d\u3093\u3001\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3068\u3057\u3066\u306f\u7570\u306a\u308b\u306e\u3067\u3001\u6bd4\u8f03\u6f14\u7b97\u5b50\u306e\u7d50\u679c\u306f\u9055\u3046\u3082\u306e\u3060\u3068\u8a00\u3063\u3066\u3044\u307e\u3059\u3002<\/p>\n<h3><span id=\"-equals4\">\uff12-\uff13\uff0eequals\u3067\u30c1\u30a7\u30c3\u30af\u3059\u3079\u304d<span>4<\/span>\u3064\u306e\u30dd\u30a4\u30f3\u30c8<\/span><\/h3>\n<p>\u3055\u3066\u3001\u30aa\u30fc\u30d0\u30fc\u30e9\u30a4\u30c9\u3057\u305f<span>equals<\/span>\u3067\u306f\u3069\u3093\u306a\u3053\u3068\u3092\u30c1\u30a7\u30c3\u30af\u3059\u308b\u3079\u304d\u3067\u3057\u3087\u3046\u304b\u3002<span>equals<\/span>\u306e\u5f15\u6570\u306e\u578b\u306f<span>Object<\/span>\u306a\u306e\u3067\u3001\u81ea\u5206\u81ea\u8eab\u3068\u540c\u3058\u30af\u30e9\u30b9\u304c\u3044\u3064\u3082\u6765\u308b\u3068\u306f\u9650\u308a\u307e\u305b\u3093\u3057\u3001<span>null<\/span>\u304b\u3069\u3046\u304b\u3082\u30c1\u30a7\u30c3\u30af\u304c\u5fc5\u8981\u305d\u3046\u3067\u3059\u306d\u3002<\/p>\n<p>equals\u3067\u306f\u3001\u4ee5\u4e0b\u306e<span>4<\/span>\u3064\u3092\u9806\u756a\u306b\u30c1\u30a7\u30c3\u30af\u3059\u308b\u3068\u3044\u3044\u3067\u3057\u3087\u3046\u3002<\/p>\n<ol>\n<li>\u81ea\u5206\u81ea\u8eab\u304b\uff1a\u6bd4\u8f03\u5148\u306e<span>Object<\/span>\u304c\u81ea\u5206\u81ea\u8eab\u306a\u3089<span>true<\/span>\u3067\u78ba\u5b9a<\/li>\n<li>\u6bd4\u8f03\u5148\u306e<span>Object<\/span>\u304c<span>null<\/span>\u304b\uff1a<span>null<\/span>\u306a\u3089<span>false<\/span>\u3067\u78ba\u5b9a<\/li>\n<li>\u81ea\u5206\u306e\u30af\u30e9\u30b9\u3068\u6bd4\u8f03\u5148\u306e<span>Object<\/span>\u306e\u30af\u30e9\u30b9\u304c\u540c\u3058\u304b\uff1a\u30af\u30e9\u30b9\u304c\u9055\u3048\u3070<span>false<\/span>\u3067\u78ba\u5b9a<\/li>\n<li>\u81ea\u5206\u306e\u30d5\u30a3\u30fc\u30eb\u30c9\u3068\u6bd4\u8f03\u5148\u306e<span>Object<\/span>\u306e\u30d5\u30a3\u30fc\u30eb\u30c9\u306e\u5185\u5bb9\u304c\u540c\u3058\u304b\uff1a\u9806\u756a\u306b\u6bd4\u8f03\u3059\u308b<\/li>\n<\/ol>\n<p>\u4ee5\u4e0b\u306f\u3001\u3053\u306e<span>4<\/span>\u3064\u306e\u30c1\u30a7\u30c3\u30af\u3092\u884c\u3063\u3066\u3044\u308b\u30b5\u30f3\u30d7\u30eb\u3067\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">import java.util.Objects;\r\n\r\nclass EqualsSample3 {\r\n\tint id;\r\n\tString name;\r\n\r\n\tEqualsSample3(int id, String name) {\r\n\t\tthis.id = id;\r\n\t\tthis.name = name;\r\n\t}\r\n\r\n\tpublic boolean equals(Object obj) {\r\n\t\t\/\/ 1.\u81ea\u5206\u81ea\u8eab\u304b\r\n\t\tif (this == obj) {\r\n\t\t\treturn true;\r\n\t\t}\r\n\r\n\t\t\/\/ 2.\u6bd4\u8f03\u5148\u306eObject\u304cnull\u304b\r\n\t\t\/\/ 3.\u81ea\u5206\u306e\u30af\u30e9\u30b9\u3068\u6bd4\u8f03\u5148\u306eObject\u306e\u30af\u30e9\u30b9\u304c\u540c\u3058\u304b\r\n\t\t\/\/ \u203binstanceof\u306f\u5de6\u8fba\u5024\u304cnull\u306a\u3089\u5e38\u306bfalse\u306a\u306e\u3067\u30012\/3\u3092\u540c\u6642\u306b\u884c\u3063\u3066\u3044\u307e\u3059\r\n\t\tif (!(obj instanceof EqualsSample3)) {\r\n\t\t\treturn false;\r\n\t\t}\r\n\r\n\t\t\/\/ 3.\u81ea\u5206\u306e\u30d5\u30a3\u30fc\u30eb\u30c9\u3068\u6bd4\u8f03\u5148\u306eObject\u306e\u30d5\u30a3\u30fc\u30eb\u30c9\u306e\u5185\u5bb9\u304c\u540c\u3058\u304b\r\n\t\tEqualsSample3 other = (EqualsSample3)obj;\r\n\r\n\t\t\/\/ \u2460id\u304c\u540c\u3058\u304b\r\n\t\tif (id != other.id) {\r\n\t\t\treturn false;\r\n\t\t}\r\n\r\n\t\t\/\/ \u2461name\u304c\u540c\u3058\u304b\r\n\t\tif (!Objects.equals(name, other.name)) {\r\n\t\t\treturn false;\r\n\t\t}\r\n\r\n\t\treturn true; \/\/ \u5168\u90e8\u540c\u3058!! this\u3068obj\u306f\u540c\u3058\u3082\u306e!!\r\n\t}\r\n\r\n\tpublic static void main(String[] args) {\r\n\t\tEqualsSample3 sample1 = new EqualsSample3(1, \"\u732b\");\r\n\t\tEqualsSample3 sample2 = new EqualsSample3(2, \"\u732b\");\r\n\t\tEqualsSample3 sample3 = new EqualsSample3(1, \"\u72ac\");\r\n\t\tEqualsSample3 sample4 = new EqualsSample3(1, \"\u732b\");\r\n\r\n\t\tSystem.out.println(sample1.equals(sample1)); \/\/ \u2192 true\u3001\u300c1.\u81ea\u5206\u81ea\u8eab\u300d\u306b\u8a72\u5f53\r\n\t\tSystem.out.println(sample1.equals(null)); \/\/ \u2192 false\u3001\u300c2.null\u306a\u3089false\u300d\u306b\u8a72\u5f53\r\n\t\tSystem.out.println(sample1.equals(\"\u732b\")); \/\/ \u2192 false\u3001\u300c3.\u30af\u30e9\u30b9\u304c\u9055\u3048\u3070false\u300d\u306b\u8a72\u5f53\r\n\t\tSystem.out.println(sample1.equals(sample2)); \/\/ \u2192 false\u3001\u300c4.\u30d5\u30a3\u30fc\u30eb\u30c9\u304c\u540c\u3058\u304b\u300d\u306b\u8a72\u5f53(id\u304c\u9055\u3046)\r\n\t\tSystem.out.println(sample1.equals(sample3)); \/\/ \u2192 false \u300c4.\u30d5\u30a3\u30fc\u30eb\u30c9\u304c\u540c\u3058\u304b\u300d\u306b\u8a72\u5f53(name\u304c\u9055\u3046)\r\n\t\tSystem.out.println(sample1.equals(sample4)); \/\/ \u2192 true\r\n\t}\r\n}<\/pre>\n<h3><span id=\"i-4\">\uff12-\uff14\uff0e\u30d5\u30a3\u30fc\u30eb\u30c9\u306e\u578b\u3054\u3068\u306e\u6bd4\u8f03\u306e\u4ed5\u65b9<\/span><\/h3>\n<p>\u3053\u3053\u3067\u306f\u3001\u30d5\u30a3\u30fc\u30eb\u30c9\u306e\u578b\u3054\u3068\u306e\u6bd4\u8f03\u306e\u4ed5\u65b9\u3092\u7c21\u5358\u306b\u307e\u3068\u3081\u307e\u3059\u3002\u53c2\u7167\u578b\u3001\u914d\u5217\u578b\u306e\u8a18\u8ff0\u306f\u3042\u304f\u307e\u3067\u57fa\u672c\u7684\u306a\u8003\u3048\u65b9\u306a\u306e\u3067\u3001\u30af\u30e9\u30b9\u306b\u6c42\u3081\u3089\u308c\u3066\u3044\u308b\u6bd4\u8f03\u6761\u4ef6\u3067\u5b9f\u88c5\u3059\u308b\u3088\u3046\u306b\u3057\u3066\u304f\u3060\u3055\u3044\u3002<\/p>\n<div class=\"attention a-2\">\n<ul>\n<li>boolean\/byte\/char\/short\/int\/long\/float\/double\uff1a \u6bd4\u8f03\u6f14\u7b97\u5b50(==)\u3067\u6bd4\u8f03\u3059\u308b<\/li>\n<li>\u53c2\u7167\u578b\uff1a \u2460\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u304c\u540c\u3058\u306a\u3089true\u3067\u78ba\u5b9a\u3001\u2461null\/not null\u304c\u5408\u308f\u306a\u3044\u5834\u5408\u306ffalse\u3067\u78ba\u5b9a\u3001\u2461\u53c2\u7167\u578b\u306eequals\u3067\u6bd4\u8f03\u3059\u308b<\/li>\n<li>\u914d\u5217\u578b\uff1a \u2460\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u304c\u540c\u3058\u306a\u3089true\u3067\u78ba\u5b9a\u3001\u2461null\/not null\u304c\u5408\u308f\u306a\u3044\u5834\u5408\u306ffalse\u3067\u78ba\u5b9a\u3001\u2462\u914d\u5217\u306e\u9577\u3055\u304c\u9055\u3048\u3070false\u3067\u78ba\u5b9a\u3001\u2463\u914d\u5217\u304c\u6301\u3064\u5024\u3092\u3059\u3079\u3066\u6bd4\u8f03\u3059\u308b<\/li>\n<\/ul>\n<\/div>\n<p>\u306a\u304a\u3001\u53c2\u7167\u578b\u30fb\u914d\u5217\u578b\u306b\u8a18\u8ff0\u3057\u305f\u65b9\u6cd5\u306f\u3001<span>java.util<\/span>\u306b\u3042\u308b<span>Objects.equals<\/span>\u3068\u3001<span>Arrays.equals\/deepEquals<\/span>\u3067\u5b9f\u88c5\u3055\u308c\u3066\u3044\u307e\u3059\u306e\u3067\u3001\u540c\u3058\u3067\u826f\u3051\u308c\u3070\u305d\u308c\u3089\u306e\u30af\u30e9\u30b9\u3092\u4f7f\u3044\u307e\u3057\u3087\u3046\u3002<\/p>\n<p>Arrays.equals\/deepEquals\u306f\u3001\u30d7\u30ea\u30df\u30c6\u30a3\u30d6\u578b\u5411\u3051\u306b\u30aa\u30fc\u30d0\u30fc\u30ed\u30fc\u30c9\u3055\u308c\u305f\u30e1\u30bd\u30c3\u30c9\u304c\u3042\u308a\u307e\u3059\u3002\u591a\u6b21\u5143\u914d\u5217\u3092\u6271\u3046\u5834\u5408\u306f\u3001<span>Arrays.deepEquals<\/span>\u304c\u4fbf\u5229\u3067\u3059\u3002\u307e\u305f\u3001\u6bd4\u8f03\u3059\u308b\u914d\u5217\u306e\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u306e\u7bc4\u56f2\u3092\u6307\u5b9a\u3067\u304d\u308b\u3082\u306e\u3082\u3042\u308a\u307e\u3059\u3088\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">import java.util.Objects;\r\nimport java.util.Arrays;\r\n\r\nclass EqualsSample4 {\r\n\tboolean booleanField;\r\n\tbyte byteField;\r\n\tchar charField;\r\n\tshort shortField;\r\n\tint intField;\r\n\tlong longField;\r\n\tfloat floatField;\r\n\tdouble doubleField;\r\n\tString objectField;\r\n\tString[] arrayField;\r\n\r\n\tpublic boolean equals(Object obj) {\r\n\t\tEqualsSample4 other = (EqualsSample4) obj;\r\n\r\n\t\t\/\/ boolean\u306e\u5834\u5408\u306f==\u3067\u6bd4\u8f03\u3059\u308b\r\n\t\tif (booleanField != other.booleanField) {\r\n\t\t\treturn false;\r\n\t\t}\r\n\r\n\t\t\/\/ byte\u306e\u5834\u5408\u306f==\u3067\u6bd4\u8f03\u3059\u308b\r\n\t\tif (byteField != other.byteField) {\r\n\t\t\treturn false;\r\n\t\t}\r\n\r\n\t\t\/\/ char\u306e\u5834\u5408\u306f==\u3067\u6bd4\u8f03\u3059\u308b\r\n\t\tif (charField != other.charField) {\r\n\t\t\treturn false;\r\n\t\t}\r\n\r\n\t\t\/\/ short\u306e\u5834\u5408\u306f==\u3067\u6bd4\u8f03\u3059\u308b\r\n\t\tif (shortField != other.shortField) {\r\n\t\t\treturn false;\r\n\t\t}\r\n\r\n\t\t\/\/ int\u306e\u5834\u5408\u306f==\u3067\u6bd4\u8f03\u3059\u308b\r\n\t\tif (intField != other.intField) {\r\n\t\t\treturn false;\r\n\t\t}\r\n\r\n\t\t\/\/ long\u306e\u5834\u5408\u306f==\u3067\u6bd4\u8f03\u3059\u308b\r\n\t\tif (longField != other.longField) {\r\n\t\t\treturn false;\r\n\t\t}\r\n\r\n\t\t\/\/ float\u306e\u5834\u5408\u306f==\u3067\u6bd4\u8f03\u3059\u308b\r\n\t\tif (floatField != other.floatField) {\r\n\t\t\treturn false;\r\n\t\t}\r\n\r\n\t\t\/\/ double\u306e\u5834\u5408\u306f==\u3067\u6bd4\u8f03\u3059\u308b\r\n\t\tif (doubleField != other.doubleField) {\r\n\t\t\treturn false;\r\n\t\t}\r\n\r\n\t\t\/\/ \u53c2\u7167\u578b\u306e\u5834\u5408\u306f\u4ee5\u4e0b\u306e\u30ed\u30b8\u30c3\u30af\u304c\u4ee3\u8868\u7684\r\n\t\tif (objectField != other.objectField) {\r\n\t\t\t\/\/ \u2460\u53c2\u7167\u5148\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u304c\u9055\u3046\u306a\u3089false\u3067\u78ba\u5b9a\r\n\t\t\treturn false;\r\n\t\t} else if (objectField == null &amp;&amp; other.objectField != null) {\r\n\t\t\t\/\/ \u2461-1 null\/not null\u306e\u7d44\u307f\u5408\u308f\u305b\u304c\u4e00\u81f4\u3057\u306a\u3044\u306a\u3089false\u3067\u78ba\u5b9a\r\n\t\t\treturn false;\r\n\t\t} else if (objectField != null &amp;&amp; other.objectField == null) {\r\n\t\t\t\/\/ \u2461-2 null\/not null\u306e\u7d44\u307f\u5408\u308f\u305b\u304c\u4e00\u81f4\u3057\u306a\u3044\u306a\u3089false\u3067\u78ba\u5b9a\r\n\t\t\treturn false;\r\n\t\t} else if (!objectField.equals(other.objectField)) {\r\n\t\t\t\/\/ \u2462\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u540c\u58eb\u306eequals\u304c\u9055\u3046\u306a\u3089false\u3067\u78ba\u5b9a\r\n\t\t\treturn false;\r\n\t\t}\r\n\r\n\/*\r\n\t\t\/\/ \u2191\u306f\u5b9f\u8cea\u7684\u306b\u306fObjects.equals\u3067\u4ee3\u66ff\u3067\u304d\u308b\r\n\t\tif (!Objects.equals(objectField, other.objectField)) {\r\n\t\t\treturn false;\r\n\t\t}\r\n*\/\r\n\r\n\t\t\/\/ \u914d\u5217\u578b\u306e\u5834\u5408\u306f\u4ee5\u4e0b\u306e\u30ed\u30b8\u30c3\u30af\u304c\u4ee3\u8868\u7684\r\n\t\tif (arrayField != other.arrayField) {\r\n\t\t\t\/\/ \u2460\u53c2\u7167\u5148\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u304c\u9055\u3046\u306a\u3089false\u3067\u78ba\u5b9a\r\n\t\t\treturn false;\r\n\t\t} else if (arrayField == null &amp;&amp; other.arrayField != null) {\r\n\t\t\t\/\/ \u2461-1 null\/not null\u306e\u7d44\u307f\u5408\u308f\u305b\u304c\u4e00\u81f4\u3057\u306a\u3044\u306a\u3089false\u3067\u78ba\u5b9a\r\n\t\t\treturn false;\r\n\t\t} else if (arrayField != null &amp;&amp; other.arrayField == null) {\r\n\t\t\t\/\/ \u2461-2 null\/not null\u306e\u7d44\u307f\u5408\u308f\u305b\u304c\u4e00\u81f4\u3057\u306a\u3044\u306a\u3089false\u3067\u78ba\u5b9a\r\n\t\t\treturn false;\r\n\t\t} else if (arrayField.length != other.arrayField.length) {\r\n\t\t\t\/\/ \u2462\u914d\u5217\u306e\u9577\u3055\u304c\u9055\u3046\u306a\u3089false\u3067\u78ba\u5b9a\r\n\t\t\treturn false;\r\n\t\t} else {\r\n\t\t\t\/\/ \u2463\u914d\u5217\u306e\u5168\u8981\u7d20\u306b\u5bfe\u3057\u3066\u540c\u3058\u304b\u78ba\u8a8d\u3059\u308b\r\n\t\t\tfor (int i = 0; i &lt; arrayField.length; i++) {\r\n\t\t\t\t\/\/ \u3053\u306e\u4f8b\u306fString[]\u306a\u306e\u3067null\u3068equals\u3067\u30c1\u30a7\u30c3\u30af\u3059\u308b\u3002\u30d7\u30ea\u30df\u30c6\u30a3\u30d6\u578b\u306a\u3089\u5358\u306b==\u3067\u826f\u3044\u3002\r\n\t\t\t\tif (arrayField[i] == null &amp;&amp; other.arrayField[i] == null) {\r\n\t\t\t\t\tcontinue;\r\n\t\t\t\t} else if (arrayField[i] == null &amp;&amp; other.arrayField[i] != null) {\r\n\t\t\t\t\treturn false;\r\n\t\t\t\t} else if (arrayField[i] != null &amp;&amp; other.arrayField[i] == null) {\r\n\t\t\t\t\treturn false;\r\n\t\t\t\t} else if (!arrayField[i].equals(other.arrayField[i])) {\r\n\t\t\t\t\treturn false;\r\n\t\t\t\t}\r\n\t\t\t}\r\n\t\t}\r\n\r\n\/*\r\n\t\t\/\/ \u2191\u306f\u5b9f\u8cea\u7684\u306b\u306fArrays.equals\u3067\u4ee3\u66ff\u3067\u304d\u308b\r\n\t\tif (!Arrays.equals(arrayField, other.arrayField)) {\r\n\t\t\treturn false;\r\n\t\t}\r\n*\/\r\n\r\n\t\treturn true;\r\n\t}\r\n}<\/pre>\n<h2><span id=\"equals\">\uff13\uff0e\u3010\u767a\u5c55\u3011<span>equals<\/span>\u3067\u306f\u3069\u3053\u307e\u3067\u30c1\u30a7\u30c3\u30af\u3059\u3079\u304d\u304b<span>?<\/span><\/span><\/h2>\n<h3><span id=\"i-5\">\uff13-\uff11\uff0e\u540c\u3058\u304b\u3069\u3046\u304b\u306e\u5224\u65ad\u306b\u4f7f\u3046\u5fc5\u8981\u306a\u7bc4\u56f2\u3060\u3051\u3068\u3059\u308b<\/span><\/h3>\n<p>equals\u3067\u3069\u3053\u307e\u3067\u30c1\u30a7\u30c3\u30af\u3059\u3079\u304d\u304b\u306f\u3001\u305d\u306e\u30af\u30e9\u30b9\u6b21\u7b2c\u3067\u3059\u3002\u305d\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u4ed6\u3068\u8b58\u5225\u3059\u308b\u30ad\u30fc\u3068\u306a\u308b\u30d5\u30a3\u30fc\u30eb\u30c9\u3060\u3051\u3067\u3082\u3044\u3044\u3067\u3059\u3057\u3001\u5168\u30d5\u30a3\u30fc\u30eb\u30c9\u3092\u30c1\u30a7\u30c3\u30af\u3057\u3066\u3082\u3044\u3044\u306e\u3067\u3059\u3002\u3064\u307e\u308a\u3001\u30c1\u30a7\u30c3\u30af\u3059\u3079\u304d\u30d5\u30a3\u30fc\u30eb\u30c9\u306f\u30af\u30e9\u30b9\u306e\u8a2d\u8a08\u8005\u304c\u6c7a\u3081\u308b\u306e\u3067\u3059\u3002<\/p>\n<p>\u307e\u305f\u3001\u30d5\u30a3\u30fc\u30eb\u30c9\u306e\u578b\u304c\u5225\u306e\u30af\u30e9\u30b9\u306e\u5834\u5408\u306f\u3001\u305d\u308c\u3089\u540c\u58eb\u3082<span>equals<\/span>\u3067\u30c1\u30a7\u30c3\u30af\u3057\u307e\u3059\u3002\u914d\u5217\u3084<span>List<\/span>\u3068\u3057\u3066\u6301\u3063\u3066\u3044\u308b\u30c7\u30fc\u30bf\u3082\u3001\u30c1\u30a7\u30c3\u30af\u304c\u5fc5\u8981\u306a\u3089\u3070\u884c\u3044\u307e\u3059\u3002\u3064\u307e\u308a\u3001\u81ea\u5206\u81ea\u8eab\u3092\u69cb\u6210\u3057\u3066\u3044\u308b\u30e2\u30ce\u306f\u3059\u3079\u3066\u30c1\u30a7\u30c3\u30af\u306e\u5bfe\u8c61\u3068\u306a\u308a\u3046\u308b\u306e\u3067\u3059\u3002\u3067\u3082\u3001\u3069\u3053\u307e\u3067\u3084\u308b\u304b\u306f\u3001\u3053\u308c\u307e\u305f\u5fc5\u8981\u6027\u6b21\u7b2c\u3067\u3059\u3002<\/p>\n<h3><span id=\"-equals-3\">\uff13-\uff12\uff0e\u8907\u6570\u306e\u6bd4\u8f03\u30ed\u30b8\u30c3\u30af\u304c\u3042\u308b\u306a\u3089\u3001<span>equals<\/span>\u3068\u306f\u5225\u306e\u30e1\u30bd\u30c3\u30c9\u3092\u4f5c\u308b<\/span><\/h3>\n<p>equals\u3092\u4f5c\u308b\u4e0a\u3067\u8907\u6570\u306e\u9078\u629e\u80a2\u304c\u3042\u308b\u5834\u5408\u3001\u305d\u306e\u30af\u30e9\u30b9\u306e\u30e6\u30fc\u30b9\u30b1\u30fc\u30b9\u3067\u4f55\u304c\u3088\u308a\u666e\u901a\u304b\u3001\u3088\u308a\u81ea\u7136\u304b\u3067\u5224\u65ad\u3057\u307e\u3059\u3002\u4f8b\u3048\u3070\u3001\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u4e0a\u306e\u30ec\u30b3\u30fc\u30c9<span>(<\/span>\u884c<span>)<\/span>\u3092\u8868\u3059\u30af\u30e9\u30b9\u306a\u3089\u3001<span>\u2460<\/span>\u5168\u5217<span>(=<\/span>\u5168\u30d5\u30a3\u30fc\u30eb\u30c9<span>)<\/span>\u306e\u4e00\u81f4\u3092\u78ba\u8a8d\u3059\u308b\u3001<span>\u2461<\/span>\u4e3b\u30ad\u30fc\u306e\u5217\u306b\u76f8\u5f53\u3059\u308b\u30d5\u30a3\u30fc\u30eb\u30c9\u3060\u3051\u78ba\u8a8d\u3059\u308b<span>\u2026<\/span>\u306e\u4e8c\u3064\u306e\u5927\u304d\u306a\u65b9\u91dd\u304c\u3042\u308a\u5f97\u307e\u3059\u3002<\/p>\n<p>\u901a\u5e38\u4f7f\u3046<span>equals<\/span>\u3068\u306f\u5225\u306b\u3001\u7279\u5225\u306a\u30ed\u30b8\u30c3\u30af\u3067\u6bd4\u8f03\u3092\u884c\u3046<span>equals<\/span>\u3092\u4f5c\u3063\u3066\u3082\u3088\u3044\u3067\u3057\u3087\u3046\u3002\u305d\u306e\u5834\u5408\u306f\u3001<span>equals<\/span>\u306e\u30aa\u30fc\u30d0\u30fc\u30ed\u30fc\u30c9\u3067\u306f\u306a\u304f\u3001\u5225\u540d\u306e\u30e1\u30bd\u30c3\u30c9\u3092\u65b0\u3057\u304f\u4f5c\u308b\u3053\u3068\u3092\u304a\u52e7\u3081\u3057\u307e\u3059\u3002\u305d\u306e\u65b9\u304c<span>equals<\/span>\u3092\u5225\u306b\u4f5c\u3063\u305f\u610f\u56f3\u304c\u660e\u78ba\u306b\u306a\u308b\u304b\u3089\u3067\u3059\u3002\u3053\u306e\u4f8b\u306f\u3001<span>String.equalsIgnoreCase<\/span>\u306a\u3069\u3067\u3059\u3002<\/p>\n<h3><span id=\"-equals-4\">\uff13-\uff13\uff0eequals\u306e\u30aa\u30fc\u30d0\u30fc\u30ed\u30fc\u30c9\u306f\u3057\u306a\u3044<\/span><\/h3>\n<p>\u5f15\u6570\u304c<span>Object<\/span>\u306e<span>equals<\/span>\u3092\u30aa\u30fc\u30d0\u30fc\u30e9\u30a4\u30c9\u305b\u305a\u306b\u9055\u3046\u578b\u3067\u30aa\u30fc\u30d0\u30fc\u30ed\u30fc\u30c9\u3059\u308b\u306e\u306f\u3001\u30d0\u30b0\u306e\u539f\u56e0\u306b\u306a\u308a\u3048\u307e\u3059\u306e\u3067\u884c\u3046\u3079\u304d\u3067\u306f\u3042\u308a\u307e\u305b\u3093\u3002\u300c\u304d\u3061\u3093\u3068<span>equals<\/span>\u3092\u4f5c\u3063\u305f\u306e\u306b\u52d5\u304b\u306a\u3044\u305e\u300d\u3068\u3044\u3046\u30b1\u30fc\u30b9\u306e\u539f\u56e0\u306f\u3001\u5927\u4f53\u3053\u308c\u3067\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">class EqualsSample5 {\r\n\tint id;\r\n\t\r\n\tEqualsSample4(int id) {\r\n\t\tthis.id = id;\r\n\t}\r\n\t\r\n\t\/\/ \u5f15\u6570\u304cEqualsSample5\u306e\u3001\u30aa\u30fc\u30d0\u30fc\u30ed\u30fc\u30c9\u3055\u308c\u305fequals\u3002\r\n\t\/\/ \u5f15\u6570\u304cObject\u306e\u3082\u306e\u3092\u3001\u660e\u793a\u7684\u306b\u30aa\u30fc\u30d0\u30fc\u30e9\u30a4\u30c9\u3057\u3066\u3044\u306a\u3044\u3002\r\n\tpublic boolean equals(EqualsSample5 sample) {\r\n\t\t\/\/ id\u3092\u4f7f\u3063\u305f\u6bd4\u8f03\u30ed\u30b8\u30c3\u30af\r\n\t}\r\n}<\/pre>\n<h2><span id=\"equals-2\">\uff14\uff0e\u3010\u767a\u5c55\u3011<span>equals<\/span>\u306b\u95a2\u3059\u308b\u3042\u308c\u3053\u308c<\/span><\/h2>\n<h3><span id=\"i-6\">\uff14-\uff11\uff0e\u300c\u9055\u3046\u304b\u300d\u3092\u8abf\u3079\u308b\u306a\u3089\u5426\u5b9a\u6f14\u7b97\u5b50\u3092\u4f7f\u3046<\/span><\/h3>\n<p>equals\u306f\u540c\u3058\u3060\u3068\u3044\u3046\u3053\u3068\u3092\u8abf\u3079\u307e\u3059\u304c\u3001\u9055\u3046\u304b\u3069\u3046\u304b\u3092\u77e5\u308a\u305f\u3044\u306a\u3089\u3001\u5426\u5b9a\u6f14\u7b97\u5b50<span>!<\/span>\u3067\u9006\u8ee2\u3055\u305b\u308c\u3070\u3044\u3044\u3060\u3051\u3067\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">String str1 = \"ABCD\";\r\nString str2 = \"EFGH\";\r\n\r\nif (!str1.equals(str2)) {\r\n\tSystem.out.println(\"str1\u3068str2\u306f\u9055\u3046\u3082\u306e\u3067\u3059\");\r\n} else {\r\n\tSystem.out.println(\"str1\u3068str2\u306f\u540c\u3058\u3082\u306e\u3067\u3059\");\r\n}<\/pre>\n<h3><span id=\"-ComparableComparatorequals\">\uff14-\uff12\uff0eComparable\/Comparator\u3068<span>equals<\/span><\/span><\/h3>\n<p>Comparable.compareTo\u3068\u3001<span>Comparator.compare<\/span>\u306f\u3001\u4e8c\u3064\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u5927\u5c0f\u6bd4\u8f03\u3057\u305f\u7d50\u679c\u3001\u300c\u540c\u3058\u300d\u3067\u3042\u308b\u306a\u3089<span>0<\/span>\u3092\u623b\u3059\u30e1\u30bd\u30c3\u30c9\u3067\u3059\u3002\u3053\u3053\u3067\u3082\u540c\u3058\u3068\u3044\u3046\u8003\u3048\u65b9\u304c\u51fa\u3066\u304d\u3066\u3044\u307e\u3059\u306d\u3002<\/p>\n<p>Object.equals\u3067\u306e\u78ba\u8a8d\u7d50\u679c\u3068\u3001<span>Comparable\/Comparator<\/span>\u3067\u306e\u78ba\u8a8d\u7d50\u679c\u306f\u3001\u540c\u3058\u306b\u3059\u308b\u3053\u3068\u304c\u300c\u5f37\u304f\u63a8\u5968\u300d\u3055\u308c\u3066\u3044\u307e\u3059\u3002\u3064\u307e\u308a\u3001<span>equals<\/span>\u304c<span>true<\/span>\u3092\u623b\u305b\u3070<span>compareTo\/compare<\/span>\u306f<span>0<\/span>\u3092\u623b\u3057\u3001<span>equals<\/span>\u304c<span>false<\/span>\u3092\u623b\u305b\u3070<span>comparaTo\/compare<\/span>\u306f<span>0<\/span>\u3067\u306f\u306a\u3044\u5024\u3092\u623b\u3059\u3079\u304d\u3060\u3068\u3044\u3046\u3053\u3068\u3067\u3059\u3002<\/p>\n<p>\u3053\u308c\u3092\u3001<span>compareTo<\/span>\u3068<span>equals<\/span>\u306e\u4e00\u8cab\u6027\u3068\u547c\u3076\u3053\u3068\u3082\u3042\u308a\u307e\u3059\u3002<span>Object.equals<\/span>\u3068<span>Comparable\/Comparator<\/span>\u306e\u7d50\u679c\u304c\u4e0d\u4e00\u81f4\u3060\u3068\u3001<span>TreeSet<\/span>\u3084<span>TreeMap<\/span>\u306a\u3069\u306e<span>equals<\/span>\u3068<span>compareTo<\/span>\u3092\u7a4d\u6975\u7684\u306b\u6d3b\u7528\u3057\u3066\u3044\u308b\u30af\u30e9\u30b9\u3092\u4f7f\u3046\u6642\u306b\u3001\u60f3\u5b9a\u3069\u304a\u308a\u306e\u52d5\u304d\u306b\u306a\u3089\u306a\u3044\u306a\u3069\u306e\u554f\u984c\u304c\u767a\u751f\u3057\u307e\u3059\u306e\u3067\u3001\u6c17\u3092\u4ed8\u3051\u307e\u3057\u3087\u3046\u3002<\/p>\n<p>compareTo\u306e\u8a73\u7d30\u306f\u3001\u4ee5\u4e0b\u306e\u8a18\u4e8b\u3092\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<h3><span id=\"-ObjecthashCodeequals\">\uff14-\uff13\uff0eObject.hashCode\u3068<span>equals<\/span><\/span><\/h3>\n<p>\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u306e\u30cf\u30c3\u30b7\u30e5\u95a2\u6570\u3068\u547c\u3079\u308b\u3082\u306e\u304c\u3001<span>int<\/span>\u3092\u623b\u3059<span>Object.hashCode<\/span>\u3067\u3059\u3002<span>hashCode<\/span>\u306f\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u7279\u5fb4\u3065\u3051\u308b\u6570\u5b57\u3001\u30cf\u30c3\u30b7\u30e5\u5024\u3092\u8fd4\u3057\u307e\u3059\u3002<\/p>\n<p>hashCode\u306f\u3001<span>HashMap<\/span>\u3084<span>HashSet<\/span>\u306e\u5185\u90e8\u306a\u3069\u3067\u4f7f\u308f\u308c\u3066\u3044\u307e\u3059\u3002\u3067\u3059\u304b\u3089\u3001<span>HashMap<\/span>\u306e\u30ad\u30fc\u3001<span>HashSet<\/span>\u306e\u5024\u306b\u4f7f\u3046\u30af\u30e9\u30b9\u3067<span>hashCode<\/span>\u304c\u9069\u5207\u306b\u4f5c\u3089\u308c\u3066\u3044\u306a\u3051\u308c\u3070\u3001\u3053\u308c\u3089\u306e\u30cf\u30c3\u30b7\u30e5\u30c6\u30fc\u30d6\u30eb\u3092\u4f7f\u3046\u30af\u30e9\u30b9\u304c\u4e88\u60f3\u3069\u304a\u308a\u306b\u52d5\u3044\u3066\u304f\u308c\u306a\u3044\u306e\u3067\u3059\u3002<\/p>\n<p>equals\u3068<span>hashCode<\/span>\u306f\u304a\u4e92\u3044\u306b\u6df1\u304f\u95a2\u4fc2\u3057\u3066\u3044\u3066\u3001\u4ee5\u4e0b\u306e\u30eb\u30fc\u30eb\u3092\u5b88\u308b\u3088\u3046\u306b\u4f5c\u3089\u306a\u3051\u308c\u3070\u306a\u308a\u307e\u305b\u3093\u3002<\/p>\n<ol>\n<li>equals\u3067\u306e\u5224\u65ad\u3067\u4f7f\u3046\u30d5\u30a3\u30fc\u30eb\u30c9\u304c\u5909\u308f\u3089\u306a\u3044\u306a\u3089\u3001<span>hashCode<\/span>\u306e\u5024\u3082\u5909\u308f\u3089\u306a\u3044<\/li>\n<li>equals\u306e\u7d50\u679c\u304c<span>true<\/span>\u306a\u3089\u3001\u9055\u3046\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3067\u3082<span>hashCode<\/span>\u306e\u5024\u306f\u540c\u3058\u306b\u306a\u308b<\/li>\n<li>equals\u306e\u7d50\u679c\u304c<span>false<\/span>\u306a\u3089\u3001<span>hashCode<\/span>\u306e\u5024\u306f\u9055\u308f\u306a\u304f\u3066\u3082\u3044\u3044<\/li>\n<\/ol>\n<p>hashCode\u306e\u8a73\u7d30\u306f\u3001\u4ee5\u4e0b\u306e\u8a18\u4e8b\u3092\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-hashcode\" 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\u3092\u9670\u304b\u3089\u652f\u3048\u308bhashCode\u3068\u306f\uff1fhashCode\u306e\u4ed5\u7d44\u307f\u3068\u5b9f\u88c5\u65b9\u6cd5' width=160 height=98 \/><\/div>\n    <div class=\"blog-card-content\">\n        <div class=\"blog-card-title\">Java\u3092\u9670\u304b\u3089\u652f\u3048\u308bhashCode\u3068\u306f\uff1fhashCode\u306e\u4ed5\u7d44\u307f\u3068\u5b9f\u88c5\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<h3><span id=\"-equals-5\">\uff14-\uff14\uff0eequals\u3092\u81ea\u52d5\u751f\u6210\u3057\u3066\u697d\u3092\u3059\u308b<\/span><\/h3>\n<p>equals\u3067\u78ba\u8a8d\u3059\u308b\u30d5\u30a3\u30fc\u30eb\u30c9\u304c\u5897\u3048\u3066\u304f\u308b\u3068\u3001\u305d\u308c\u3089\u306e\u30d5\u30a3\u30fc\u30eb\u30c9\u3054\u3068\u306e\u78ba\u8a8d\u51e6\u7406\u3092\u304d\u3061\u3093\u3068\u4f5c\u308a\u8fbc\u3093\u3067\u3001\u52d5\u4f5c\u78ba\u8a8d\u3092\u3059\u308b\u3060\u3051\u3067\u3082\u4e00\u82e6\u52b4\u3067\u3059\u3002\u3067\u3059\u304c\u3001<span>IDE<\/span>\u3084\u30e9\u30a4\u30d6\u30e9\u30ea\u3092\u4e0a\u624b\u306b\u4f7f\u3046\u3068\u3001\u304d\u3061\u3093\u3068\u3057\u305f<span>equals<\/span>\u3092\u7c21\u5358\u306b\u81ea\u52d5\u751f\u6210\u3067\u304d\u305f\u308a\u3059\u308b\u306e\u3067\u3059<span>!! <\/span>\u3053\u3053\u3067\u5b66\u3093\u3067\u3001\u305c\u3072\u3069\u3093\u3069\u3093\u6d3b\u7528\u3057\u307e\u3057\u3087\u3046\u3002<\/p>\n<h4>\uff14-\uff14-\uff11\uff0eIDE\u306e\u6a5f\u80fd\u3092\u4f7f\u3046<\/h4>\n<p>Eclipse\u3001<span>IntelliJ IDEA<\/span>\u3001<span>NetBeans<\/span>\u306a\u3069\u306e<span>Java<\/span>\u5411\u3051<span>IDE<\/span>\u3067\u306f\u3001<span>equals<\/span>\u3092\u81ea\u52d5\u751f\u6210\u3057\u3066\u304f\u308c\u308b\u6a5f\u80fd\u304c\u3042\u308a\u307e\u3059\u3002\u3053\u3053\u3067\u306f<span>Eclipse<\/span>\u3067\u306e\u4f8b\u3092\u793a\u3057\u307e\u3059\u3002<\/p>\n<p>\u4f8b\u3048\u3070\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u30af\u30e9\u30b9\u304c\u3042\u3063\u305f\u3068\u3057\u307e\u3059\u3002\u3053\u306e\u30af\u30e9\u30b9\u306b<span>Eclipse<\/span>\u3067<span>equals<\/span>\u3092\u81ea\u52d5\u751f\u6210\u3057\u3066\u307f\u307e\u3057\u3087\u3046\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">class EqualsSample6 {\r\n\tint intField;\r\n\tString strField;\r\n\tObject objField;\r\n}<\/pre>\n<p>\u3053\u306e\u30af\u30e9\u30b9\u3092\u30d1\u30c3\u30b1\u30fc\u30b8\u30a8\u30af\u30b9\u30d7\u30ed\u30fc\u30e9\u306a\u3069\u304b\u3089\u3001\u300c\u53f3\u30af\u30ea\u30c3\u30af\u300d<span>\u2192<\/span>\u300c\u30bd\u30fc\u30b9\u300d<span>\u2192<\/span>\u300c<span>hashCode()<\/span>\u304a\u3088\u3073<span>equals()<\/span>\u306e\u751f\u6210\u300d\u3092\u9078\u3073\u307e\u3059\u3002\u3059\u308b\u3068\u300c<span>hashCode()<\/span>\u304a\u3088\u3073<span>equals()<\/span>\u306e\u751f\u6210\u300d\u30a6\u30a3\u30b6\u30fc\u30c9\u304c\u8868\u793a\u3055\u308c\u308b\u306e\u3067\u3001<span>equals<\/span>\u3068<span>hashCode<\/span>\u306e\u5bfe\u8c61\u3068\u3057\u305f\u3044\u30d5\u30a3\u30fc\u30eb\u30c9\u3092\u9078\u3073\u3001<span>OK<\/span>\u30dc\u30bf\u30f3\u3092\u62bc\u3057\u307e\u3059\u3002<\/p>\n<p>\u3059\u308b\u3068\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306b<span>equals<\/span>\u3068<span>hashCode<\/span>\u304c\u81ea\u52d5\u751f\u6210\u3055\u308c\u307e\u3057\u305f\u3002\u5c11\u3005\u3054\u3061\u3083\u3054\u3061\u3083\u3057\u305f\u30bd\u30fc\u30b9\u30b3\u30fc\u30c9\u3067\u3059\u304c\u3001\u304d\u3061\u3093\u3068\u52d5\u304d\u307e\u3059\u3002\u305d\u308c\u306b\u3001\u5b9f\u88c5\u3057\u3065\u3089\u3044<span>hashCode<\/span>\u3082<span>equals<\/span>\u3068\u540c\u671f\u3092\u53d6\u3063\u3066\u751f\u6210\u3057\u3066\u304f\u308c\u308b\u306e\u306f\u3001\u5927\u5909\u52a9\u304b\u308a\u307e\u3059\u306d\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">class EqualsSample6 {\r\n\tint intField;\r\n\tString strField;\r\n\tObject objField;\r\n\r\n\t@Override\r\n\tpublic int hashCode() {\r\n\t\tfinal int prime = 31;\r\n\t\tint result = 1;\r\n\t\tresult = prime * result + intField;\r\n\t\tresult = prime * result + ((objField == null) ? 0 : objField.hashCode());\r\n\t\tresult = prime * result + ((strField == null) ? 0 : strField.hashCode());\r\n\t\treturn result;\r\n\t}\r\n\r\n\t@Override\r\n\tpublic boolean equals(Object obj) {\r\n\t\tif (this == obj)\r\n\t\t\treturn true;\r\n\t\tif (obj == null)\r\n\t\t\treturn false;\r\n\t\tif (getClass() != obj.getClass())\r\n\t\t\treturn false;\r\n\t\tEqualsSample6 other = (EqualsSample6) obj;\r\n\t\tif (intField != other.intField)\r\n\t\t\treturn false;\r\n\t\tif (objField == null) {\r\n\t\t\tif (other.objField != null)\r\n\t\t\t\treturn false;\r\n\t\t} else if (!objField.equals(other.objField))\r\n\t\t\treturn false;\r\n\t\tif (strField == null) {\r\n\t\t\tif (other.strField != null)\r\n\t\t\t\treturn false;\r\n\t\t} else if (!strField.equals(other.strField))\r\n\t\t\treturn false;\r\n\t\treturn true;\r\n\t}\r\n\r\n}<\/pre>\n<blockquote>\n<p>\u00a0 \u00a0 \u00a0 \u00a0 \u3010\u53c2\u8003\u3011<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 IntelliJ IDEA\u306e\u81ea\u52d5\u751f\u6210\u30a6\u30a3\u30b6\u30fc\u30c9<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <a href=\"https:\/\/www.jetbrains.com\/help\/idea\/generate-equals-and-hashcode-wizard.html\">https:\/\/www.jetbrains.com\/help\/idea\/generate-equals-and-hashcode-wizard.html<\/a><\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u2192[\u82f1\u8a9e<span>]IntelliJ IDEA<\/span>\u306e\u8a72\u5f53\u90e8\u5206\u306e\u30de\u30cb\u30e5\u30a2\u30eb\u3067\u3059\u3002<\/p>\n<p>&nbsp;<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 NetBeans\u3067\u306e\u81ea\u52d5\u751f\u6210\u624b\u9806<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<a href=\"https:\/\/blogs.oracle.com\/java\/ten-time-savers-in-netbeans-v2\" class=\"broken_link\"> https:\/\/blogs.oracle.com\/java\/ten-time-savers-in-netbeans-v2<\/a><\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u2192[\u82f1\u8a9e<span>]<\/span>\u300c<span>Number 2: Auto-generate getters and setters, constructors and more!<\/span>\u300d\u306e\u3068\u3053\u308d\u306b\u624b\u9806\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n<p>&nbsp;<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <a href=\"https:\/\/stackoverflow.com\/questions\/38242576\/can-netbeans-auto-generate-correct-hashcode-and-equals-methods-for-a-mapping\">https:\/\/stackoverflow.com\/questions\/38242576\/can-netbeans-auto-generate-correct-hashcode-and-equals-methods-for-a-mapping<\/a><\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u2192[\u82f1\u8a9e<span>]equals<\/span>\u3092\u81ea\u52d5\u3059\u308b\u64cd\u4f5c\u306e\u7c21\u5358\u306a\u624b\u9806\u304c\u7d39\u4ecb\u3055\u308c\u3066\u3044\u307e\u3059\u3002<\/p>\n<\/blockquote>\n<h4>\uff14-\uff14-\uff12\uff0e\u30e9\u30a4\u30d6\u30e9\u30ea\u3092\u4f7f\u3046<span>(Lombok<\/span>\u306a\u3069<span>)<\/span><\/h4>\n<p>equals\u306f<span>IDE<\/span>\u306b\u81ea\u52d5\u751f\u6210\u3055\u305b\u308b\u4ee5\u5916\u306b\u3082\u3001\u5916\u90e8\u30e9\u30a4\u30d6\u30e9\u30ea\u3092\u4f7f\u3063\u3066\u81ea\u52d5\u751f\u6210\u3059\u308b\u65b9\u6cd5\u3082\u3042\u308a\u307e\u3059\u3002\u4ee3\u8868\u7684\u306a\u306e\u306f\u3001<span>Lombok<\/span>\u3068\u3044\u3046\u30e9\u30a4\u30d6\u30e9\u30ea\u3092\u4f7f\u3046\u3053\u3068\u3067\u3059\u3002<\/p>\n<p>Lombok\u306e\u8a73\u7d30\u3084\u4f7f\u3048\u308b\u3088\u3046\u306b\u3059\u308b\u624b\u9806\u306f\u7701\u304d\u307e\u3059\u304c\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u30af\u30e9\u30b9\u3078\u30a2\u30ce\u30c6\u30fc\u30b7\u30e7\u30f3\u300c<span>@EqualsAndHashCode<\/span>\u300d\u3092\u4ed8\u3051\u308b\u3060\u3051\u3067\u3001\u30af\u30e9\u30b9\u306b\u3042\u308b\u30d5\u30a3\u30fc\u30eb\u30c9\u3092\u4f7f\u3063\u305f<span>equals<\/span>\u3068<span>hashCode<\/span>\u3092\u81ea\u52d5\u7684\u306b\u4f5c\u3063\u3066\u304f\u308c\u307e\u3059<span>!!(\u203b) <\/span>\u3082\u306e\u3059\u3054\u304f\u697d\u3061\u3093\u3067\u3059\u306d\u3002<\/p>\n<p>\u203bJava\u306e\u30bd\u30fc\u30b9\u30b3\u30fc\u30c9\u4e0a\u306b\u306f<span>equals<\/span>\u3068<span>hashCode<\/span>\u306f\u4f5c\u6210\u3055\u308c\u305a\u3001\u30b3\u30f3\u30d1\u30a4\u30eb\u3057\u305f\u7d50\u679c\u306e\u30af\u30e9\u30b9\u30d5\u30a1\u30a4\u30eb<span>(.class)<\/span>\u306e\u4e2d\u3060\u3051\u306b\u3001\u30aa\u30fc\u30d0\u30fc\u30e9\u30a4\u30c9\u3055\u308c\u305f\u30e1\u30bd\u30c3\u30c9\u306e\u5b9f\u88c5\u304c\u81ea\u52d5\u7684\u306b\u542b\u307e\u308c\u307e\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">import lombok.EqualsAndHashCode;\r\n\r\n@EqualsAndHashCode\r\npublic class EqualsSample4 {\r\n\tint intField;\r\n\tString strField;\r\n\tObject objField;\r\n}<\/pre>\n<blockquote>\n<p>\u00a0 \u00a0 \u00a0 \u00a0 \u3010\u53c2\u8003\u3011<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Project Lombok<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <a href=\"https:\/\/projectlombok.org\/\">https:\/\/projectlombok.org\/<\/a><\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u2192[\u82f1\u8a9e<span>]<\/span>\u30d7\u30ed\u30b8\u30a7\u30af\u30c8\u306e<span>WEB<\/span>\u30da\u30fc\u30b8\u3067\u3059<\/p>\n<p>&nbsp;<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 @EqualsAndHashCode<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <a href=\"https:\/\/projectlombok.org\/features\/EqualsAndHashCode\">https:\/\/projectlombok.org\/features\/EqualsAndHashCode<\/a><\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u2192[\u82f1\u8a9e<span>]<\/span>\u516c\u5f0f<span>WEB<\/span>\u30da\u30fc\u30b8\u5185\u306e\u3001<span>@EqualsAndHashCode<\/span>\u306e\u8aac\u660e\u30da\u30fc\u30b8\u3067\u3059\u3002<\/p>\n<\/blockquote>\n<h2><span id=\"i-7\">\uff15\uff0e\u307e\u3068\u3081<\/span><\/h2>\n<p>\u3053\u306e\u8a18\u4e8b\u3067\u306f\u3001<span>Object.equals<\/span>\u3092\u8aac\u660e\u3057\u3066\u304d\u307e\u3057\u305f\u3002<span>equals<\/span>\u306f\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u540c\u58eb\u304c\u610f\u5473\u7684\u306b\u540c\u3058\u304b\u3092\u8abf\u3079\u308b\u30e1\u30bd\u30c3\u30c9\u3067\u3001\u30af\u30e9\u30b9\u306e\u30d5\u30a3\u30fc\u30eb\u30c9\u540c\u58eb\u3092\u6bd4\u8f03\u3057\u3066\u540c\u3058\u60c5\u5831\u3092\u6301\u3063\u3066\u3044\u308b\u304b\u3092\u8abf\u3079\u305f\u7d50\u679c\u3092\u623b\u3057\u307e\u3059\u3002\u305d\u3057\u3066\u3001\u6bd4\u8f03\u6f14\u7b97\u5b50\u306e<span>==<\/span>\u3068\u306f\u3001\u4f7f\u3044\u3069\u3053\u308d\u304c\u5927\u304d\u304f\u9055\u3063\u3066\u3044\u308b\u306e\u3067\u3059\u3002<\/p>\n<p>\u81ea\u5206\u3067\u4f5c\u3063\u305f\u30af\u30e9\u30b9\u3067<span>equals<\/span>\u3092\u30aa\u30fc\u30d0\u30fc\u30e9\u30a4\u30c9\u3057\u3066\u3044\u306a\u3044\u3068\u3001\u8272\u3005\u306a\u3068\u3053\u308d\u3067\u56f0\u3063\u305f\u3053\u3068\u306b\u306a\u308a\u307e\u3059\u3002\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u6307\u5411\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u8a00\u8a9e\u3067\u3042\u308b<span>Java<\/span>\u3067\u306f\u3001\u81ea\u5206\u304c\u4ed6\u8005\u3068\u540c\u3058\u304b\u3092\u5224\u65ad\u3059\u308b\u306e\u306f\u81ea\u5206\u81ea\u8eab\u304c\u3084\u308b\u3079\u304d\u3053\u3068\u3067\u3042\u3063\u3066\u3001\u6c7a\u3057\u3066\u4ed6\u4eba\u4efb\u305b\u306b\u306f\u3067\u304d\u306a\u3044\u5927\u4e8b\u306a\u51e6\u7406\u3067\u3059\u3002<\/p>\n<p>equals\u3092\u6b63\u3057\u304f\u4f5c\u308c\u3070\u3001<span>Java<\/span>\u306e\u6a19\u6e96<span>API<\/span>\u306b\u3042\u308b\u8272\u3005\u306a\u30af\u30e9\u30b9\u3092\u3001\u6b63\u3057\u304f\u4fbf\u5229\u306b\u4f7f\u3048\u308b\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3002\u5c11\u3057\u96e3\u3057\u3044\u8003\u3048\u65b9\u304c\u6c42\u3081\u3089\u308c\u308b\u3068\u3053\u308d\u3082\u3042\u308a\u307e\u3059\u304c\u3001\u3057\u3063\u304b\u308a\u3068\u30dd\u30a4\u30f3\u30c8\u3092\u62bc\u3055\u3048\u3066\u6d3b\u7528\u3067\u304d\u308b\u3088\u3046\u306b\u306a\u308a\u307e\u3057\u3087\u3046\u3002<\/p>\n<p>\u3061\u306a\u307f\u306b\u3001\u3082\u3063\u3068\u6df1\u304f<span>equals<\/span>\u3092\u77e5\u308a\u305f\u3044\u5834\u5408\u306f\u3001\u4f8b\u3048\u3070\u66f8\u7c4d\u300c<span>Effective Java<\/span>\u300d\u306b\u4e8b\u7d30\u304b\u304f\u8a18\u8ff0\u3055\u308c\u3066\u3044\u307e\u3059\u306e\u3067\u3001\u305d\u3061\u3089\u3092\u3054\u53c2\u7167\u304f\u3060\u3055\u3044\u3002\u305d\u3053\u306b\u66f8\u304b\u308c\u3066\u3044\u308b\u3053\u3068\u7406\u89e3\u3059\u308c\u3070\u3001\u3042\u306a\u305f\u3082\u3059\u3063\u304b\u308a<span>equals<\/span>\u30de\u30b9\u30bf\u30fc\u3067\u3059\u3088<span>!!<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Java\u306eObject\u30af\u30e9\u30b9\u306b\u3042\u308b\u30e1\u30bd\u30c3\u30c9equals\u306f\u3001\u4f55\u304b\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u540c\u58eb\u304c\u300c\u540c\u3058\u300d\u304b\u3092\u8abf\u3079\u308b\u30e1\u30bd\u30c3\u30c9\u3067\u3059\u3002 \u3053\u3053\u3067\u8a00\u3046\u300c\u540c\u3058\u300d\u306b\u3064\u3044\u3066\u3001\u610f\u5473\u3068\u3057\u3066\u540c\u3058\u304b\u3001\u5b9f\u4f53\u3068\u3057\u3066\u540c\u3058\u304b\u306e\u533a\u5225\u304cJava\u3067\u306f\u3055\u308c\u308b\u306e\u3067\u3059\u3002\u305d\u3057\u3066\u3001 [&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\/1375"}],"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=1375"}],"version-history":[{"count":8,"href":"https:\/\/www.bold.ne.jp\/engineer-club\/wp-json\/wp\/v2\/posts\/1375\/revisions"}],"predecessor-version":[{"id":5771,"href":"https:\/\/www.bold.ne.jp\/engineer-club\/wp-json\/wp\/v2\/posts\/1375\/revisions\/5771"}],"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=1375"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bold.ne.jp\/engineer-club\/wp-json\/wp\/v2\/categories?post=1375"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}