{"id":9847,"date":"2025-09-05T16:00:20","date_gmt":"2025-09-05T07:00:20","guid":{"rendered":"https:\/\/techmania.jp\/blog\/?p=9847"},"modified":"2025-10-17T18:14:39","modified_gmt":"2025-10-17T09:14:39","slug":"php-isset","status":"publish","type":"post","link":"https:\/\/techmania.jp\/blog\/php-isset\/","title":{"rendered":"\u3010PHP\u5165\u9580\u3011isset\u95a2\u6570\u3067\u5909\u6570\u304c\u30bb\u30c3\u30c8\u3055\u308c\u3066\u3044\u308b\u304b\u3069\u3046\u304b\u3092\u78ba\u8a8d\u3059\u308b"},"content":{"rendered":"\n<p>\u30d7\u30ed\u30b0\u30e9\u30e0\u306e\u5b9f\u884c\u4e2d\u3001\u5024\u306e\u683c\u7d0d\u3055\u308c\u3066\u3044\u306a\u3044\u5909\u6570\u3084\u3001 NULL\u306e\u5165\u3063\u305f\u5909\u6570\u3092\u53c2\u7167\u3059\u308b\u3053\u3068\u306b\u3088\u3063\u3066\u3001\u4f8b\u5916\u30a8\u30e9\u30fc\u304c\u767a\u751f\u3059\u308b\u30b1\u30fc\u30b9\u304c\u3088\u304f\u3042\u308a\u307e\u3059\u3002<\/p>\n\n\n\n<p>\u305d\u3046\u3057\u305f\u554f\u984c\u3092\u89e3\u6c7a\u3059\u308b\u65b9\u6cd5\u3068\u3057\u3066\u3001\u4e8b\u524d\u306b\u5909\u6570\u306e\u5024\u3092\u78ba\u8a8d\u3059\u308b\u65b9\u6cd5\u304c\u3042\u308a\u307e\u3059\u304c\u3001\u305d\u306e\u969b\u306b\u6d3b\u7528\u3067\u304d\u308b\u95a2\u6570\u304c PHP \u306b\u306f\u7528\u610f\u3055\u308c\u3066\u3044\u307e\u3059\u3002<\/p>\n\n\n\n<p>\u4eca\u56de\u306f\u3001\u305d\u306e\u95a2\u6570\u306e\u3046\u3061\u306e\uff11\u3064\u3067\u3042\u308b \u300cisset\u300d \u95a2\u6570\u306b\u3064\u3044\u3066\u3001\u8a73\u3057\u304f\u89e3\u8aac\u3057\u3066\u3044\u304d\u305f\u3044\u3068\u601d\u3044\u307e\u3059\u3002<\/p>\n\n\n\n<h2 id=\"outline__1\" class=\"wp-block-heading\">isset\u95a2\u6570\u306e\u4f7f\u3044\u65b9<\/h2>\n\n\n\n<p>isset\u95a2\u6570\u306e\u8a73\u3057\u3044\u4f7f\u3044\u65b9\u306b\u3064\u3044\u3066\u3001\u9806\u306b\u898b\u3066\u3044\u304d\u307e\u3057\u3087\u3046\u3002<\/p>\n\n\n\n<h3 id=\"outline__1_1\" class=\"wp-block-heading\">\u57fa\u672c\u69cb\u6587<\/h3>\n\n\n\n<p>\u307e\u305a\u306f\u3001\u57fa\u672c\u69cb\u6587\u304b\u3089\u89e3\u8aac\u3057\u3066\u3044\u304d\u307e\u3059\u3002<\/p>\n\n\n\n<p>isset\u95a2\u6570\u3092\u4f7f\u7528\u3059\u308b\u969b\u306f\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u69cb\u6587\u3067\u8a18\u8ff0\u3057\u307e\u3059\u3002<\/p>\n\n\n\n<p><strong>\u3010\u57fa\u672c\u69cb\u6587\u3011<\/strong><\/p>\n\n\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-php\" data-lang=\"PHP\"><code>isset($\u5909\u6570\u540d1 [, $\u5909\u6570\u540d2 ...] )<\/code><\/pre><\/div>\n\n\n\n<p>\u5f15\u6570\u306b\u306f\u3001\u5024\u306e\u6709\u7121\u3092\u78ba\u8a8d\u3057\u305f\u3044\u5909\u6570\u306e\u540d\u524d\u3092\u6307\u5b9a\u3057\u307e\u3059\u3002<br>\u5909\u6570\u540d\u306f\u8907\u6570\u6307\u5b9a\u3059\u308b\u3053\u3068\u304c\u53ef\u80fd\u3067\u3059\u3002<\/p>\n\n\n\n<p>\u95a2\u6570\u306e\u623b\u308a\u5024\u306f\u3001\u771f\u507d\u5024\u304c\u8fd4\u5374\u3055\u308c\u307e\u3059\u3002<br>\u5024\u304c\u8a2d\u5b9a\u3055\u308c\u3066\u304a\u308a\u3001\u304b\u3064 NULL \u304c\u683c\u7d0d\u3055\u308c\u3066\u3044\u306a\u3044\u5834\u5408\u306b true\u3001\u305d\u3046\u3067\u306a\u3051\u308c\u3070 false\u304c\u7d50\u679c\u3068\u3057\u3066\u8fd4\u3055\u308c\u307e\u3059\u3002<\/p>\n\n\n\n<p>\u307e\u305f\u3001\u8907\u6570\u306e\u5909\u6570\u3092\u6307\u5b9a\u3057\u305f\u5834\u5408\u306f\u3001\u5168\u3066\u306e\u5909\u6570\u306b NULL \u4ee5\u5916\u306e\u5024\u304c\u30bb\u30c3\u30c8\u3055\u308c\u3066\u3044\u308b\u5834\u5408\u306e\u307f\u3001true\u304c\u8fd4\u3055\u308c\u307e\u3059\u3002<\/p>\n\n\n\n<p>\u4ee5\u4e0b\u306e\u30b5\u30f3\u30d7\u30eb\u30b3\u30fc\u30c9\u3067\u3001\u5b9f\u969b\u306e\u52d5\u304d\u3092\u78ba\u8a8d\u3057\u3066\u307f\u307e\u3057\u3087\u3046\u3002<\/p>\n\n\n\n<p>\u3010\u30b5\u30f3\u30d7\u30eb\u30b3\u30fc\u30c9\u3011<\/p>\n\n\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-php\" data-lang=\"PHP\"><code>&lt;?php\n\n$sampleSet1 = &#39;\u5024\u304c\u3042\u308a\u307e\u3059&#39;;\n$sampleSet2 = 10;\n$sampleUnset;\n$sampleNULL = null;\n\n\/\/ \u5358\u4f53\u3067\u306e\u78ba\u8a8d\u7d50\u679c\nvar_dump(isset($sampleSet1));\nvar_dump(isset($sampleSet2));\nvar_dump(isset($sampleUnset));\nvar_dump(isset($sampleNULL));\n\n\/\/ \u8907\u6570\u6307\u5b9a\u3067\u306e\u78ba\u8a8d\u7d50\u679c\nvar_dump(isset($sampleSet1, $sampleSet2));\nvar_dump(isset($sampleSet1, $sampleUnset));\nvar_dump(isset($sampleSet1, $sampleNULL));\n\n?&gt;<\/code><\/pre><\/div>\n\n\n\n<p><strong>\u3010\u5b9f\u884c\u7d50\u679c\u3011<\/strong><\/p>\n\n\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-plain\"><code>bool(true)\nbool(true)\nbool(false)\nbool(false)\n\nbool(true)\nbool(false)\nbool(false)<\/code><\/pre><\/div>\n\n\n\n<p>\u3053\u306e\u3088\u3046\u306b\u3001\u5024\u304c\u7a7a\u306e\u5834\u5408\u3060\u3051\u3067\u306a\u304f\u3001NULL \u304c\u683c\u7d0d\u3055\u308c\u3066\u3044\u308b\u5834\u5408\u3082\u5224\u5b9a\u306f false \u3068\u306a\u308a\u307e\u3059\u3002<br>\u305d\u306e\u305f\u3081\u3001 NULL \u4ee5\u5916\u306e\u5024\u304c\u78ba\u5b9f\u306b\u683c\u7d0d\u3055\u308c\u3066\u3044\u308b\u3053\u3068\u3092\u78ba\u8a8d\u3057\u305f\u3044\u5834\u5408\u306b\u3001\u3053\u306e\u95a2\u6570\u3092\u6d3b\u7528\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n\n\n\n<p>\u305f\u3060\u3057\u3001\u4e00\u70b9\u6c17\u3092\u4ed8\u3051\u308b\u3079\u304d\u30dd\u30a4\u30f3\u30c8\u3068\u3057\u3066\u3001\u7a7a\u6587\u5b57\u306f\u5024\u304c\u683c\u7d0d\u3055\u308c\u3066\u3044\u308b\u3082\u306e\u3068\u307f\u306a\u3057\u3066 true \u6271\u3044\u3068\u306a\u308b\u305f\u3081\u3001\u6ce8\u610f\u304c\u5fc5\u8981\u3067\u3059\u3002<\/p>\n\n\n\n<h3 id=\"outline__1_2\" class=\"wp-block-heading\">if\u6587\u306e\u6761\u4ef6\u5f0f\u3067\u4f7f\u7528\u3059\u308b<\/h3>\n\n\n\n<p>isset\u95a2\u6570\u306e\u623b\u308a\u5024\u306f\u771f\u507d\u5024\u3067\u3042\u308b\u305f\u3081\u3001if\u6587\u306e\u6761\u4ef6\u5206\u3068\u3057\u3066\u6d3b\u7528\u3059\u308b\u3053\u3068\u3082\u3067\u304d\u307e\u3059\u3002<\/p>\n\n\n\n<p>\u4ee5\u4e0b\u306e\u30b5\u30f3\u30d7\u30eb\u30b3\u30fc\u30c9\u3067\u52d5\u304d\u3092\u898b\u3066\u307f\u307e\u3057\u3087\u3046\u3002<\/p>\n\n\n\n<p><strong>\u3010\u30b5\u30f3\u30d7\u30eb\u30b3\u30fc\u30c9\u3011<\/strong><\/p>\n\n\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-php\" data-lang=\"PHP\"><code>&lt;?php\n\n$sampleSet = &#39;\u3053\u308c\u306f\u30b5\u30f3\u30d7\u30eb\u30b3\u30fc\u30c9\u3067\u3059\u3002&#39;;\n\nif(isset($sampleSet)){\n    echo $sampleSet, &quot;\\n&quot;;\n\n}else{\n    echo &#39;\u5024\u304c\u30bb\u30c3\u30c8\u3055\u308c\u3066\u3044\u307e\u305b\u3093&#39;, &quot;\\n&quot;;\n}\n\n?&gt;<\/code><\/pre><\/div>\n\n\n\n<p><strong>\u3010\u5b9f\u884c\u7d50\u679c\u3011<\/strong><\/p>\n\n\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-plain\"><code>\u3053\u308c\u306f\u30b5\u30f3\u30d7\u30eb\u30b3\u30fc\u30c9\u3067\u3059\u3002<\/code><\/pre><\/div>\n\n\n\n<p>\u4e0a\u8a18\u306e\u30b5\u30f3\u30d7\u30eb\u30b3\u30fc\u30c9\u306e\u5834\u5408\u306f\u3001isset\u95a2\u6570\u3067\u78ba\u8a8d\u3057\u305f\u5909\u6570\u306b\u6587\u5b57\u5217\u304c\u683c\u7d0d\u3055\u308c\u3066\u3044\u308b\u305f\u3081\u3001true \u306e\u5834\u5408\u306e\u51e6\u7406\u304c\u5b9f\u884c\u3055\u308c\u3066\u3044\u307e\u3059\u3002<\/p>\n\n\n\n<p>\u3053\u308c\u3092\u5fdc\u7528\u3057\u3001\u4f8b\u3048\u3070\u5165\u529b\u30d5\u30a9\u30fc\u30e0\u306e\u30c7\u30fc\u30bf\u9001\u4fe1\u6642\u306b\u4f55\u304b\u3057\u3089\u306e\u6587\u5b57\u304c\u5165\u529b\u3055\u308c\u3066\u3044\u308b\u304b\u3092\u78ba\u8a8d\u3059\u308b\u306a\u3069\u3001\u69d8\u3005\u306a\u30b1\u30fc\u30b9\u3067\u6d3b\u7528\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n\n\n\n<p><strong>\u3010\u30b5\u30f3\u30d7\u30eb\u30b3\u30fc\u30c9\u3011<\/strong><\/p>\n\n\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-php\" data-lang=\"PHP\"><code>if (!isset($_POST[&#39;name&#39;]){\n  echo &#39;\u540d\u524d\u3092\u5165\u529b\u3057\u3066\u304f\u3060\u3055\u3044&#39;;\n}<\/code><\/pre><\/div>\n\n\n\n<h3 id=\"outline__1_3\" class=\"wp-block-heading\">\u4e09\u9805\u6f14\u7b97\u5b50\u3067\u4f7f\u7528\u3059\u308b<\/h3>\n\n\n\n<p>\u5148\u307b\u3069if\u6587\u306e\u6761\u4ef6\u5f0f\u306b isset\u95a2\u6570\u3092\u6d3b\u7528\u3059\u308b\u65b9\u6cd5\u306b\u3064\u3044\u3066\u89e3\u8aac\u3057\u307e\u3057\u305f\u304c\u3001\u30b1\u30fc\u30b9\u306b\u3088\u3063\u3066\u306f\u4e09\u9805\u6f14\u7b97\u5b50\u3092\u4f7f\u7528\u3059\u308b\u3053\u3068\u3067\u3088\u308a\u7c21\u6f54\u306b\u51e6\u7406\u3092\u8a18\u8ff0\u3067\u304d\u308b\u5834\u5408\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n\n\n\n<p>\u4ee5\u4e0b\u306e\u30b5\u30f3\u30d7\u30eb\u30b3\u30fc\u30c9\u3067\u3001\u5b9f\u969b\u306e\u4f7f\u3044\u65b9\u3092\u898b\u3066\u307f\u307e\u3057\u3087\u3046\u3002<\/p>\n\n\n\n<p><strong>\u3010\u30b5\u30f3\u30d7\u30eb\u30b3\u30fc\u30c9\u3011<\/strong><\/p>\n\n\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-php\" data-lang=\"PHP\"><code>&lt;?php\n\n$sampleSet = &#39;\u3053\u308c\u306f\u30b5\u30f3\u30d7\u30eb\u30b3\u30fc\u30c9\u3067\u3059\u3002&#39;;\n\n\/\/ \u4e09\u9805\u6f14\u7b97\u5b50\u3092\u4f7f\u7528\n$result = isset($sampleSet) ? $sampleSet : &#39;\u5024\u304c\u30bb\u30c3\u30c8\u3055\u308c\u3066\u3044\u307e\u305b\u3093&#39;;\necho $result, &quot;\\n&quot;;\n\n?&gt;<\/code><\/pre><\/div>\n\n\n\n<p><strong>\u3010\u5b9f\u884c\u7d50\u679c\u3011<\/strong><\/p>\n\n\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-plain\"><code>\u3053\u308c\u306f\u30b5\u30f3\u30d7\u30eb\u30b3\u30fc\u30c9\u3067\u3059\u3002<\/code><\/pre><\/div>\n\n\n\n<p>\u5909\u6570 result \u306b\u5024\u3092\u683c\u7d0d\u3059\u308b\u969b\u306b\u4f7f\u7528\u3057\u3066\u3044\u308b\u306e\u304c\u4e09\u9805\u6f14\u7b97\u5b50\u3067\u3059\u3002<br>\u540c\u69d8\u306e\u5185\u5bb9\u3092 if\u6587\u306b\u66f8\u304d\u63db\u3048\u308b\u3068\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u30b3\u30fc\u30c9\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n\n\n\n<p><strong>\u3010\u30b5\u30f3\u30d7\u30eb\u30b3\u30fc\u30c9\u3011<\/strong><\/p>\n\n\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-php\" data-lang=\"PHP\"><code>&lt;?php\n\n$sampleSet = &#39;\u3053\u308c\u306f\u30b5\u30f3\u30d7\u30eb\u30b3\u30fc\u30c9\u3067\u3059\u3002&#39;;\n\nif(isset($sampleSet)){\n    $result = $sampleSet;\n}else{\n    $result = &#39;\u5024\u304c\u30bb\u30c3\u30c8\u3055\u308c\u3066\u3044\u307e\u305b\u3093&#39;;\n}\n\n?&gt;<\/code><\/pre><\/div>\n\n\n\n<p>\u898b\u6bd4\u3079\u3066\u307f\u308b\u3068\u3001\u4e09\u9805\u6f14\u7b97\u5b50\u306b\u3088\u3063\u3066\u30b3\u30fc\u30c9\u304c\u7c21\u7565\u5316\u3055\u308c\u3066\u3044\u308b\u306e\u304c\u5206\u304b\u308a\u307e\u3059\u306d\u3002<\/p>\n\n\n\n<p>\u4f7f\u7528\u53ef\u80fd\u306a\u30b1\u30fc\u30b9\u304b\u3069\u3046\u304b\u3001\u3069\u3061\u3089\u306e\u65b9\u304c\u3088\u308a\u8aad\u307f\u3084\u3059\u3044\u30b3\u30fc\u30c9\u306b\u306a\u308b\u304b\u306f\u5834\u5408\u306b\u3088\u308a\u307e\u3059\u304c\u3001\u899a\u3048\u3066\u304a\u304f\u3068\u4fbf\u5229\u306a\u8a18\u8ff0\u65b9\u6cd5\u3067\u3059\u3002<\/p>\n\n\n\n<h2 id=\"outline__2\" class=\"wp-block-heading\">\u914d\u5217\u306b\u7a7a\u306e\u8981\u7d20\u304c\u542b\u307e\u308c\u308b\u304b\u3092\u8abf\u3079\u308b<\/h2>\n\n\n\n<p>isset\u95a2\u6570\u3092\u4f7f\u7528\u3057\u3066\u3001\u914d\u5217\u306b\u7a7a\u306e\u8981\u7d20\u304c\u542b\u307e\u308c\u3066\u3044\u308b\u304b\u3069\u3046\u304b\u3092\u78ba\u8a8d\u3059\u308b\u3053\u3068\u3082\u3067\u304d\u307e\u3059\u304c\u3001\u4f7f\u7528\u306e\u969b\u306b\u306f\u6c17\u3092\u4ed8\u3051\u308b\u3079\u304d\u30dd\u30a4\u30f3\u30c8\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n\n\n\n<p>\u307e\u305a\u306f\u3001\u4ee5\u4e0b\u306e\u30b5\u30f3\u30d7\u30eb\u30b3\u30fc\u30c9\u3092\u898b\u3066\u304f\u3060\u3055\u3044\u3002<\/p>\n\n\n\n<p><strong>\u3010\u30b5\u30f3\u30d7\u30eb\u30b3\u30fc\u30c9\u3011<\/strong><\/p>\n\n\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-php\" data-lang=\"PHP\"><code>&lt;?php\n\n$array1 = [1, 2, 3, 4, 5];\n$array2 = [1, 2, null];\n \nvar_dump(isset($array1));\nvar_dump(isset($array2));\n\n?&gt;<\/code><\/pre><\/div>\n\n\n\n<p><strong>\u3010\u5b9f\u884c\u7d50\u679c\u3011<\/strong><\/p>\n\n\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-plain\"><code>bool(true)\nbool(true)<\/code><\/pre><\/div>\n\n\n\n<p>\u30b3\u30fc\u30c9\u3092\u898b\u3066\u307f\u308b\u3068\u3001\u7247\u65b9\u306e\u914d\u5217\u306b\u306f NULL \u304c\u542b\u307e\u308c\u3066\u3044\u308b\u306e\u304c\u5206\u304b\u308a\u307e\u3059\u304c\u3001\u7d50\u679c\u306f\u3069\u3061\u3089\u3082 true \u3068\u306a\u3063\u3066\u3044\u307e\u3059\u3002<\/p>\n\n\n\n<p>\u3053\u306e\u3088\u3046\u306b\u3001\u5f15\u6570\u306b\u914d\u5217\u305d\u306e\u3082\u306e\u3092\u6307\u5b9a\u3059\u308b\u3068\u7d50\u679c\u304c\u6b63\u5e38\u306b\u8868\u793a\u3055\u308c\u306a\u3044\u305f\u3081\u3001\u8981\u7d20\u306e\uff11\u3064\uff11\u3064\u3092\u53d6\u308a\u51fa\u3057\u3066\u5224\u5b9a\u3059\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n\n\n\n<p><strong>\u3010\u30b5\u30f3\u30d7\u30eb\u30b3\u30fc\u30c9\u3011<\/strong><\/p>\n\n\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-plain\"><code>&lt;?php\n\n$array = [1, 2, null, 4, 5];\n\nforeach ($array as $key =&gt; $value) {\n  var_dump(isset($array[$key]));\n}\n\n?&gt;<\/code><\/pre><\/div>\n\n\n\n<p><strong>\u3010\u5b9f\u884c\u7d50\u679c\u3011<\/strong><\/p>\n\n\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-plain\"><code>bool(true)\nbool(true)\nbool(false)\nbool(true)\nbool(true)<\/code><\/pre><\/div>\n\n\n\n<p>\u9023\u60f3\u914d\u5217\u306e\u8981\u7d20\u3092\u78ba\u8a8d\u3059\u308b\u969b\u3082\u540c\u69d8\u3068\u306a\u308a\u307e\u3059\u3002<\/p>\n\n\n\n<p><strong>\u3010\u30b5\u30f3\u30d7\u30eb\u30b3\u30fc\u30c9\u3011<\/strong><\/p>\n\n\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-plain\"><code>&lt;?php\n\n$humanArray = [\n    &#39;Tanaka&#39; =&gt; 15, \n    &#39;Yamada&#39; =&gt; 20, \n    &#39;Sato&#39; =&gt; null,\n    &#39;Suzuki&#39; =&gt; 18,\n    &#39;Endo&#39; =&gt; 23\n];\n\n\/\/ \u6b63\u3057\u304f\u8868\u793a\u3055\u308c\u306a\u3044\nvar_dump(isset($humanArray));\n\n\/\/ \u8981\u7d20\u3092\u53d6\u308a\u51fa\u3057\u3066\u78ba\u8a8d\u3059\u308b\nvar_dump(isset($humanArray[&#39;Sato&#39;]));\n\n?&gt;<\/code><\/pre><\/div>\n\n\n\n<p><strong>\u3010\u5b9f\u884c\u7d50\u679c\u3011<\/strong><\/p>\n\n\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-plain\"><code>bool(true)\nbool(false)<\/code><\/pre><\/div>\n\n\n\n<h2 id=\"outline__3\" class=\"wp-block-heading\">empty\u95a2\u6570\u3067\u5909\u6570\u306e\u5024\u304c\u7a7a\u3067\u3042\u308b\u304b\u3092\u78ba\u8a8d\u3059\u308b<\/h2>\n\n\n\n<p>isset\u95a2\u6570\u3068\u3088\u304f\u4f3c\u305f\u52d5\u304d\u3092\u3059\u308b\u95a2\u6570\u306b\u3001empty\u95a2\u6570\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n\n\n\n<p>empty\u95a2\u6570\u3092\u4f7f\u7528\u3059\u308b\u969b\u306f\u3001\u4ee5\u4e0b\u306e\u69cb\u6587\u3067\u8a18\u8ff0\u3057\u307e\u3059\u3002<\/p>\n\n\n\n<p><strong>\u3010\u57fa\u672c\u69cb\u6587\u3011<\/strong><\/p>\n\n\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-php\" data-lang=\"PHP\"><code>bool empty ( $\u5909\u6570\u540d )<\/code><\/pre><\/div>\n\n\n\n<p>\u4e21\u8005\u306e\u3082\u3063\u3068\u3082\u5927\u304d\u306a\u9055\u3044\u306f\u3001\u7a7a\u6587\u5b57\u306a\u3069\u304c\u5909\u6570\u306b\u683c\u7d0d\u3055\u308c\u3066\u3044\u308b\u5834\u5408\u306b\u3001\u7a7a\u306e\u72b6\u614b\u3067\u3042\u308b\u3068\u5224\u5b9a\u3055\u308c\u308b\u304b\u5426\u304b\u306b\u3042\u308a\u307e\u3059\u3002<\/p>\n\n\n\n<p>isset\u95a2\u6570\u3067\u306f\u3001\u672a\u5b9a\u7fa9\u72b6\u614b\u3068 NULL \u306e\u5834\u5408\u306e\u307f\u304c\u7a7a\u3067\u3042\u308b\u3068\u5224\u5b9a\u3055\u308c\u307e\u3059\u304c\u3001empty\u95a2\u6570\u306e\u5834\u5408\u306f\u7a7a\u6587\u5b57\u306a\u3069\u3082\u6761\u4ef6\u306b\u542b\u307e\u308c\u307e\u3059\u3002<\/p>\n\n\n\n<p>\u5177\u4f53\u7684\u306b\u306f\u3001\u4ee5\u4e0b\u306e\u6761\u4ef6\u306f\u5168\u3066\u5024\u304c\u7a7a\u3067\u3042\u308b\u3068\u5224\u65ad\u3055\u308c\u307e\u3059\u3002<\/p>\n\n\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-plain\"><code>&#39;&#39; (\u7a7a\u6587\u5b57\u5217)\n0 (\u6574\u6570)\n0.0 (\u6d6e\u52d5\u5c0f\u6570\u70b9\u6570)\n&quot;0&quot; (\u6587\u5b57\u5217\u306e 0)\nNULL\nfalse<\/code><\/pre><\/div>\n\n\n\n<p>\u307e\u305f\u3001isset\u95a2\u6570\u3068\u306f\u623b\u308a\u5024\u306e\u6761\u4ef6\u304c\u9006\u3068\u306a\u308b\u306e\u3067\u6ce8\u610f\u304c\u5fc5\u8981\u3067\u3059\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>isset\u95a2\u6570\uff1a\u7a7a\u306e\u5834\u5408\u306f false<\/li>\n\n\n\n<li>empty\u95a2\u6570\uff1a\u7a7a\u306e\u5834\u5408\u306f true<\/li>\n<\/ul>\n\n\n\n<p>\u4ee5\u4e0b\u306e\u30b5\u30f3\u30d7\u30eb\u30b3\u30fc\u30c9\u3067\u3001\u305d\u308c\u305e\u308c\u306e\u52d5\u304d\u306e\u9055\u3044\u3092\u898b\u3066\u307f\u307e\u3057\u3087\u3046\u3002<\/p>\n\n\n\n<p><strong>\u3010\u30b5\u30f3\u30d7\u30eb\u30b3\u30fc\u30c9\u3011<\/strong><\/p>\n\n\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-php\" data-lang=\"PHP\"><code>&lt;?php\n\n$nullStr = null;\n$emptyStr = &#39;&#39;;\n\n\/\/ isset\u95a2\u6570\u306e\u5834\u5408\nvar_dump(isset($nullStr));\nvar_dump(isset($emptyStr));\n\n\/\/ empty\u95a2\u6570\u306e\u5834\u5408\nvar_dump(empty($emptyStr));\nvar_dump(empty($emptyStr));\n\n?&gt;<\/code><\/pre><\/div>\n\n\n\n<p><strong>\u3010\u5b9f\u884c\u7d50\u679c\u3011<\/strong><\/p>\n\n\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-plain\"><code>bool(false)\nbool(true)\n\nbool(true)\nbool(true)<\/code><\/pre><\/div>\n\n\n\n<p>\u7a7a\u306e\u5834\u5408\u306e\u623b\u308a\u5024\u306e\u9055\u3044\u3084\u3001\u5024\u304c\u7a7a\u3067\u3042\u308b\u3068\u5224\u65ad\u3059\u308b\u57fa\u6e96\u304c\u7570\u306a\u3063\u3066\u3044\u308b\u306e\u304c\u5206\u304b\u308a\u307e\u3059\u306d\u3002<br>\u5224\u65ad\u3059\u308b\u6761\u4ef6\u306b\u3088\u3063\u3066\u3001\uff12\u3064\u306e\u95a2\u6570\u3092\u4f7f\u3044\u5206\u3051\u308b\u3068\u3044\u3044\u3067\u3057\u3087\u3046\u3002<\/p>\n\n\n\n<h2 id=\"outline__4\" class=\"wp-block-heading\">\u7279\u5b9a\u306e\u5b9a\u6570\u304c\u5b58\u5728\u3057\u3066\u3044\u308b\u304b\u3092defined\u95a2\u6570\u3067\u8abf\u3079\u308b<\/h2>\n\n\n\n<p>\u5909\u6570\u3067\u306f\u306a\u304f\u3001\u5b9a\u6570\u306e\u6709\u7121\u3092\u78ba\u8a8d\u3057\u305f\u3044\u5834\u5408\u306f\u3001defined\u95a2\u6570\u3092\u4f7f\u7528\u3057\u3066\u8abf\u3079\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n\n\n\n<p>defined\u95a2\u6570\u306e\u57fa\u672c\u69cb\u6587\u306f\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u8a18\u8ff0\u3057\u307e\u3059\u3002<\/p>\n\n\n\n<p><strong>\u3010\u57fa\u672c\u69cb\u6587\u3011<\/strong><\/p>\n\n\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-php\" data-lang=\"PHP\"><code>defined(\u5b9a\u6570\u540d)<\/code><\/pre><\/div>\n\n\n\n<p>\u6307\u5b9a\u3057\u305f\u5b9a\u6570\u304c\u5b9a\u7fa9\u3055\u308c\u3066\u3044\u308b\u5834\u5408\u306f true\u3001\u7121\u3051\u308c\u3070 false \u304c\u8fd4\u5374\u3055\u308c\u307e\u3059\u3002<\/p>\n\n\n\n<p><strong>\u3010\u30b5\u30f3\u30d7\u30eb\u30b3\u30fc\u30c9\u3011<\/strong><\/p>\n\n\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-php\" data-lang=\"PHP\"><code>&lt;?php\n\ndefine(&#39;CONSTSAMPLE&#39;, 10);\n\nvar_dump(defined(&#39;CONSTSAMPLE&#39;)); \n\n?&gt;<\/code><\/pre><\/div>\n\n\n\n<p><strong>\u3010\u5b9f\u884c\u7d50\u679c\u3011<\/strong><\/p>\n\n\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-plain\"><code>bool(true)<\/code><\/pre><\/div>\n\n\n\n<h2 id=\"outline__5\" class=\"wp-block-heading\">\u307e\u3068\u3081<\/h2>\n\n\n\n<p>\u4e88\u671f\u3057\u306a\u3044\u30a8\u30e9\u30fc\u3092\u672a\u7136\u306b\u9632\u3050\u305f\u3081\u306b\u3001\u5909\u6570\u306e\u4e2d\u8eab\u3092\u78ba\u8a8d\u3057\u3066\u304a\u304f\u3053\u3068\u306f\u91cd\u8981\u3067\u3059\u3002<br>\u4eca\u56de\u7d39\u4ecb\u3057\u305f isset \u95a2\u6570\u3084 empty \u95a2\u6570\u306a\u3069\u3092\u6d3b\u7528\u3057\u3066\u3001\u30d7\u30ed\u30b0\u30e9\u30e0\u3092\u3088\u308a\u5b89\u5168\u306b\u904b\u7528\u3057\u3066\u3044\u304d\u307e\u3057\u3087\u3046\u3002<\/p>\n\n\n\n<h2 id=\"outline__6\" class=\"wp-block-heading\">PHP\u306e\u52c9\u5f37\u65b9\u6cd5\u306f\uff1f<\/h2>\n\n\n<p>\u66f8\u7c4d\u3084\u30a4\u30f3\u30bf\u30fc\u30cd\u30c3\u30c8\u3067\u5b66\u7fd2\u3059\u308b\u65b9\u6cd5\u304c\u3042\u308a\u307e\u3059\u3002\u6628\u4eca\u3067\u306f\u3001YouTube\u306a\u3069\u306e\u52d5\u753b\u30b5\u30a4\u30c8\u3084\u30a8\u30f3\u30b8\u30cb\u30a2\u306e\u30b3\u30df\u30e5\u30cb\u30c6\u30a3\u30b5\u30a4\u30c8\u306a\u3069\u3082\u5145\u5b9f\u3057\u3066\u3044\u3066\u591a\u304f\u306e\u60c5\u5831\u304c\u624b\u306b\u5165\u308a\u307e\u3059\u3002<br \/>\u305d\u3057\u3066\u3001\u3088\u308a\u52b9\u7387\u7684\u306b\u77e5\u8b58\u30fb\u30b9\u30ad\u30eb\u3092\u7fd2\u5f97\u3059\u308b\u306b\u306f\u3001\u77e5\u8b58\u3092\u3064\u3051\u306a\u304c\u3089\u5b9f\u969b\u306b\u624b\u3092\u52d5\u304b\u3057\u3066\u307f\u308b\u306a\u3069\u3001\u30a4\u30f3\u30d7\u30c3\u30c8\u3068\u30a2\u30a6\u30c8\u30d7\u30c3\u30c8\u3092\u7e70\u308a\u8fd4\u3057\u3066\u3044\u304f\u3053\u3068\u304c\u91cd\u8981\u3067\u3059\u3002\u7279\u306b\u72ec\u5b66\u306e\u5834\u5408\u306f\u3001\u6709\u8b58\u8005\u306b\u8cea\u554f\u304c\u3067\u304d\u305f\u308a\u30d5\u30a3\u30fc\u30c9\u30d0\u30c3\u30af\u3092\u3082\u3089\u3048\u308b\u3088\u3046\u306a\u74b0\u5883\u304c\u3042\u308b\u3068\u3001\u7406\u89e3\u5ea6\u304c\u6df1\u307e\u308b\u3067\u3057\u3087\u3046\u3002<\/p>\n<p>\u305f\u3060\u3001PHP\u306b\u9650\u3089\u305a\u3001IT\u30b9\u30ad\u30eb\u3092\u8eab\u306b\u3064\u3051\u308b\u969b\u3001\u3069\u3046\u3057\u3066\u3082\u8ab2\u984c\u306b\u3076\u3064\u304b\u3063\u3066\u3057\u307e\u3046\u3053\u3068\u306f\u3042\u308a\u307e\u3059\u3088\u306d\u3002\u7279\u306b\u72ec\u5b66\u3060\u3068\u3001\u308f\u304b\u3089\u306a\u3044\u90e8\u5206\u3092\u30d7\u30ed\u306b\u8cea\u554f\u3067\u304d\u308b\u6a5f\u4f1a\u3092\u78ba\u4fdd\u3057\u306b\u304f\u304f\u3001\u30e2\u30c1\u30d9\u30fc\u30b7\u30e7\u30f3\u304c\u7d9a\u304d\u306b\u304f\u3044\u3068\u3044\u3046\u5074\u9762\u304c\u3042\u308a\u307e\u3059\u3002\u72ec\u5b66\u3067\u30e2\u30c1\u30d9\u30fc\u30b7\u30e7\u30f3\u3092\u7dad\u6301\u3059\u308b\u81ea\u4fe1\u304c\u306a\u3044\u4eba\u306b\u306f\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u30b9\u30af\u30fc\u30eb\u3068\u3044\u3046\u624b\u3082\u3042\u308a\u307e\u3059\u3002\u8cbb\u7528\u306f\u639b\u304b\u308a\u307e\u3059\u304c\u3001\u305d\u306e\u5206\u30b9\u30ad\u30eb\u3092\u8eab\u306b\u3064\u3051\u3084\u3059\u3044\u3067\u3059\u3002\u3057\u3063\u304b\u308a\u3068\u77e5\u8b58\u30fb\u30b9\u30ad\u30eb\u3092\u7fd2\u5f97\u3057\u3066\u5b9f\u8df5\u306b\u6d3b\u304b\u3057\u305f\u3044\u3068\u3044\u3046\u4eba\u306f\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u30b9\u30af\u30fc\u30eb\u304c\u304a\u3059\u3059\u3081\u3067\u3059\u3002<\/p>\n<p><span class=\"markerYellow\"><strong>\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u30b9\u30af\u30fc\u30eb\u306a\u3089\u30c6\u30c3\u30af\u30de\u30cb\u30a2\u304c\u304a\u3059\u3059\u3081\uff01<\/strong><\/span><\/p>\n\n\n<img decoding=\"async\" src=\"https:\/\/web-img.rensa.jp.net\/rensa\/images\/techmania\/thumbnail\/images\/yuudou.png\" class=\"post-img\" 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NULL\u306e\u5165\u3063\u305f\u5909\u6570\u3092\u53c2\u7167\u3059\u308b\u3053\u3068\u306b\u3088\u3063\u3066\u3001\u4f8b\u5916\u30a8\u30e9\u30fc\u304c\u767a\u751f\u3059\u308b\u30b1\u30fc\u30b9\u304c\u3088\u304f\u3042\u308a\u307e\u3059\u3002 \u305d\u3046\u3057\u305f\u554f\u984c\u3092\u89e3\u6c7a\u3059\u308b\u65b9\u6cd5\u3068\u3057\u3066\u3001\u4e8b\u524d\u306b\u5909\u6570\u306e\u5024\u3092\u78ba\u8a8d\u3059\u308b\u65b9\u6cd5\u304c\u3042\u308a\u307e\u3059\u304c\u3001\u305d\u306e\u969b\u306b\u6d3b\u7528\u3067\u304d\u308b\u95a2\u6570\u304c PHP \u306b\u306f\u7528\u610f\u3055\u308c\u3066\u3044\u307e\u3059\u3002 \u4eca\u56de\u306f\u3001\u305d\u306e\u95a2\u6570\u306e\u3046\u3061\u306e\uff11\u3064\u3067\u3042\u308b \u300cisset\u300d \u95a2\u6570\u306b\u3064\u3044\u3066\u3001\u8a73\u3057\u304f\u89e3\u8aac\u3057\u3066\u3044\u304d\u305f\u3044\u3068\u601d\u3044\u307e\u3059\u3002 isset\u95a2\u6570\u306e\u4f7f\u3044\u65b9 i [&hellip;]","protected":false},"author":11,"featured_media":9849,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"fifu_image_url":"https:\/\/web-img.rensa.jp.net\/rensa\/images\/techmania\/thumbnail\/images\/php-isset.webp","fifu_image_alt":"\u3010PHP\u5165\u9580\u3011isset\u95a2\u6570\u3067\u5909\u6570\u304c\u30bb\u30c3\u30c8\u3055\u308c\u3066\u3044\u308b\u304b\u3069\u3046\u304b\u3092\u78ba\u8a8d\u3059\u308b","footnotes":""},"categories":[15],"tags":[],"class_list":["post-9847","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-programming"],"_links":{"self":[{"href":"https:\/\/techmania.jp\/blog\/wp-json\/wp\/v2\/posts\/9847","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/techmania.jp\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/techmania.jp\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/techmania.jp\/blog\/wp-json\/wp\/v2\/users\/11"}],"replies":[{"embeddable":true,"href":"https:\/\/techmania.jp\/blog\/wp-json\/wp\/v2\/comments?post=9847"}],"version-history":[{"count":3,"href":"https:\/\/techmania.jp\/blog\/wp-json\/wp\/v2\/posts\/9847\/revisions"}],"predecessor-version":[{"id":9855,"href":"https:\/\/techmania.jp\/blog\/wp-json\/wp\/v2\/posts\/9847\/revisions\/9855"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/techmania.jp\/blog\/wp-json\/wp\/v2\/media\/9849"}],"wp:attachment":[{"href":"https:\/\/techmania.jp\/blog\/wp-json\/wp\/v2\/media?parent=9847"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/techmania.jp\/blog\/wp-json\/wp\/v2\/categories?post=9847"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/techmania.jp\/blog\/wp-json\/wp\/v2\/tags?post=9847"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}