{"id":13736,"date":"2026-06-24T09:13:35","date_gmt":"2026-06-24T09:13:35","guid":{"rendered":"https:\/\/withcode.tech\/media\/javascript%e3%81%a7dom%e6%93%8d%e4%bd%9c%e3%82%92%e3%83%9e%e3%82%b9%e3%82%bf%e3%83%bc%e3%81%99%e3%82%8b%e5%85%a5%e9%96%80%e3%82%ac%e3%82%a4%e3%83%89%ef%bd%9c%e8%a6%81%e7%b4%a0%e3%81%ae%e5%8f%96\/"},"modified":"2026-07-28T04:25:25","modified_gmt":"2026-07-28T04:25:25","slug":"javascript-dom-manipulation-guide","status":"publish","type":"post","link":"https:\/\/withcode.tech\/media\/javascript-dom-manipulation-guide\/","title":{"rendered":"JavaScript\u3067DOM\u64cd\u4f5c\u3092\u30de\u30b9\u30bf\u30fc\u3059\u308b\u5165\u9580\u30ac\u30a4\u30c9\uff5c\u8981\u7d20\u306e\u53d6\u5f97\u30fb\u5909\u66f4\u30fb\u30a4\u30d9\u30f3\u30c8\u51e6\u7406\u3092\u57fa\u790e\u304b\u3089\u5b9f\u8df5\u307e\u3067\u89e3\u8aac"},"content":{"rendered":"\n<!-- withmedia-ketsuron -->\n<h2 class=\"wp-block-heading\">\u3053\u306e\u8a18\u4e8b\u306e\u7d50\u8ad6<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">DOM\uff08Document Object Model\uff09\u3068\u306f\u3001HTML\u306e\u69cb\u9020\u3092JavaScript\u304b\u3089\u64cd\u4f5c\u3059\u308b\u305f\u3081\u306e\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\u3067\u3001\u30d6\u30e9\u30a6\u30b6\u304cHTML\u3092\u5185\u90e8\u3067\u30c4\u30ea\u30fc\u72b6\u306e\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u306b\u5909\u63db\u3057\u305f\u3082\u306e\u3067\u3059\u3002DOM\u64cd\u4f5c\u306f\u300c\u8981\u7d20\u3092\u53d6\u5f97\u3059\u308b\u2192\u5185\u5bb9\u3092\u5909\u66f4\u3059\u308b\u2192\u30b9\u30bf\u30a4\u30eb\u3084\u30af\u30e9\u30b9\u3092\u64cd\u4f5c\u3059\u308b\u2192\u30a4\u30d9\u30f3\u30c8\u3092\u51e6\u7406\u3059\u308b\u300d\u3068\u3044\u3046\u6d41\u308c\u304c\u57fa\u672c\u3067\u3001getElementById\u3084querySelector\u3067\u8981\u7d20\u3092\u53d6\u5f97\u3057\u3001textContent\u3084classList\u3001addEventListener\u3092\u4f7f\u3063\u3066\u30da\u30fc\u30b8\u3092\u52d5\u7684\u306b\u66f8\u304d\u63db\u3048\u307e\u3059\u3002\u3053\u306e\u611f\u899a\u3092\u3064\u304b\u3081\u3070\u3001\u30dc\u30bf\u30f3\u64cd\u4f5c\u3067\u306e\u8868\u793a\u5207\u308a\u66ff\u3048\u3084\u30d5\u30a9\u30fc\u30e0\u30d0\u30ea\u30c7\u30fc\u30b7\u30e7\u30f3\u306a\u3069\u3001\u3042\u3089\u3086\u308b\u30a4\u30f3\u30bf\u30e9\u30af\u30c6\u30a3\u30d6\u306aUI\u3092\u5b9f\u88c5\u3067\u304d\u307e\u3059\u3002<\/p>\n\n\n<div class=\"swell-block-balloon\">\n<div class=\"c-balloon -bln-left\" data-col=\"gray\">\n<div class=\"c-balloon__icon -square\"><img decoding=\"async\" src=\"https:\/\/withcode.tech\/media\/wp-content\/uploads\/2025\/06\/\u30b9\u30af\u30ea\u30fc\u30f3\u30b7\u30e7\u30c3\u30c8-2025-06-15-14.40.37.jpg\" alt=\"\" class=\"c-balloon__iconImg\" width=\"80px\" height=\"80px\"><span class=\"c-balloon__iconName\">\u751f\u5f92<\/span><\/div>\n<div class=\"c-balloon__body -speaking -border-none\"><div class=\"c-balloon__text\"><p><strong>JavaScript\u3063\u3066HTML\u3092\u3069\u3046\u3084\u3063\u3066\u5909\u3048\u308b\u3093\u3067\u3059\u304b\uff1fCSS\u3068\u306e\u9055\u3044\u3082\u3088\u304f\u308f\u304b\u3089\u306a\u304f\u3066\u3001DOM\u64cd\u4f5c\u3068\u3044\u3046\u30ef\u30fc\u30c9\u304c\u51fa\u3066\u304f\u308b\u305f\u3073\u306b\u6b62\u307e\u3063\u3066\u3057\u307e\u3044\u307e\u3059\u2026\u3002<\/strong><\/p><span class=\"c-balloon__shapes\"><span class=\"c-balloon__before\"><\/span><span class=\"c-balloon__after\"><\/span><\/span><\/div><\/div>\n<\/div>\n<\/div>\n\n<div class=\"swell-block-balloon\">\n<div class=\"c-balloon -bln-right\" data-col=\"gray\">\n<div class=\"c-balloon__icon -square\"><img decoding=\"async\" src=\"https:\/\/withcode.tech\/media\/wp-content\/uploads\/2025\/06\/\u30b9\u30af\u30ea\u30fc\u30f3\u30b7\u30e7\u30c3\u30c8-2025-06-15-15.11.23.jpg\" alt=\"\" class=\"c-balloon__iconImg\" width=\"80px\" height=\"80px\"><span class=\"c-balloon__iconName\">\u30da\u30f3\u535a\u58eb<\/span><\/div>\n<div class=\"c-balloon__body -speaking -border-none\"><div class=\"c-balloon__text\"><p><strong>DOM\u64cd\u4f5c\u306fJavaScript\u306e\u6838\u5fc3\u3067\u3059\uff01\u3053\u306e\u8a18\u4e8b\u3067\u306f\u300c\u8981\u7d20\u306e\u53d6\u5f97\u2192\u5185\u5bb9\u306e\u5909\u66f4\u2192\u30af\u30e9\u30b9\u64cd\u4f5c\u2192\u30a4\u30d9\u30f3\u30c8\u51e6\u7406\u300d\u3068\u3044\u30464\u30b9\u30c6\u30c3\u30d7\u3067\u3001\u5b9f\u969b\u306b\u52d5\u304f\u30b3\u30fc\u30c9\u3092\u4f7f\u3044\u306a\u304c\u3089\u5b8c\u5168\u306b\u7406\u89e3\u3067\u304d\u308b\u3088\u3046\u89e3\u8aac\u3057\u307e\u3059\u3088\u3002<\/strong><\/p><span class=\"c-balloon__shapes\"><span class=\"c-balloon__before\"><\/span><span class=\"c-balloon__after\"><\/span><\/span><\/div><\/div>\n<\/div>\n<\/div>\n\n<p class=\"wp-block-paragraph\">\u300cJavaScript\u306f\u66f8\u3051\u308b\u3051\u3069DOM\u64cd\u4f5c\u306b\u306a\u308b\u3068\u9014\u7aef\u306b\u624b\u304c\u6b62\u307e\u308b\u300d\u2014\u2014Web\u5236\u4f5c\u3092\u5b66\u3073\u306f\u3058\u3081\u305f\u65b9\u304b\u3089\u3088\u304f\u805e\u304f\u60a9\u307f\u3067\u3059\u3002\u3053\u306e\u8a18\u4e8b\u3067\u306f\u3001DOM\u3068\u306f\u4f55\u304b\u3068\u3044\u3046\u57fa\u790e\u6982\u5ff5\u304b\u3089\u3001\u8981\u7d20\u306e\u53d6\u5f97\u30fb\u30c6\u30ad\u30b9\u30c8\u30fb\u30b9\u30bf\u30a4\u30eb\u30fb\u30af\u30e9\u30b9\u306e\u5909\u66f4\u3001\u305d\u3057\u3066\u30af\u30ea\u30c3\u30af\u3084\u30d5\u30a9\u30fc\u30e0\u5165\u529b\u306a\u3069\u306e\u30a4\u30d9\u30f3\u30c8\u51e6\u7406\u307e\u3067\u3001\u5b9f\u969b\u306b\u30d6\u30e9\u30a6\u30b6\u3067\u52d5\u304f\u30b3\u30fc\u30c9\u4f8b\u3092\u8ef8\u306b\u30b9\u30c6\u30c3\u30d7\u3054\u3068\u306b\u89e3\u8aac\u3057\u307e\u3059\u3002\u8aad\u307f\u7d42\u3048\u305f\u5f8c\u306b\u306f\u300cJavaScript\u3067\u30da\u30fc\u30b8\u3092\u52d5\u304b\u3059\u300d\u3068\u3044\u3046\u611f\u899a\u304c\u5177\u4f53\u7684\u306b\u3064\u304b\u3081\u308b\u306f\u305a\u3067\u3059\u3002HTML\u30fbCSS\u306e\u57fa\u790e\u306f\u5b66\u3093\u3060\u3082\u306e\u306eJavaScript\u306e\u5b9f\u8df5\u7684\u306a\u4f7f\u3044\u65b9\u304c\u66d6\u6627\u306a\u65b9\u306b\u7279\u306b\u5f79\u7acb\u3064\u5185\u5bb9\u3067\u3059\u3002<\/p>\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n<h2 class=\"wp-block-heading\">DOM\uff08\u30c9\u30ad\u30e5\u30e1\u30f3\u30c8\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u30e2\u30c7\u30eb\uff09\u3068\u306f\u4f55\u304b<\/h2>\n\n<p class=\"wp-block-paragraph\">DOM\uff08Document Object Model\uff09\u3068\u306f\u3001<strong><span class=\"swl-marker mark_yellow\">HTML\u306e\u69cb\u9020\u3092JavaScript\u304b\u3089\u64cd\u4f5c\u3059\u308b\u305f\u3081\u306e\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\uff08\u4ed5\u7d44\u307f\uff09<\/span><\/strong>\u3067\u3059\u3002\u30d6\u30e9\u30a6\u30b6\u306fHTML\u30d5\u30a1\u30a4\u30eb\u3092\u8aad\u307f\u8fbc\u3080\u3068\u3001\u5185\u90e8\u3067\u300c\u30c4\u30ea\u30fc\u72b6\u306e\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u300d\u306b\u5909\u63db\u3057\u307e\u3059\u3002\u3053\u306e\u6728\u69cb\u9020\u306e\u30c7\u30fc\u30bf\u304cDOM\u3067\u3059\u3002<\/p>\n\n<p class=\"wp-block-paragraph\">\u305f\u3068\u3048\u3070\u4ee5\u4e0b\u306e\u3088\u3046\u306aHTML\u304c\u3042\u308b\u3068\u3057\u307e\u3059\u3002<\/p>\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-html\" data-lang=\"HTML\"><code>&lt;!DOCTYPE html&gt;\n&lt;html&gt;\n  &lt;body&gt;\n    &lt;h1 id=\"title\"&gt;\u306f\u3058\u3081\u3066\u306eDOM&lt;\/h1&gt;\n    &lt;p class=\"description\"&gt;JavaScript\u3067\u64cd\u4f5c\u3067\u304d\u307e\u3059\u3002&lt;\/p&gt;\n  &lt;\/body&gt;\n&lt;\/html&gt;<\/code><\/pre><\/div>\n\n<p class=\"wp-block-paragraph\">\u30d6\u30e9\u30a6\u30b6\u306f\u3053\u308c\u3092\u30c4\u30ea\u30fc\u3068\u3057\u3066\u5185\u90e8\u7ba1\u7406\u3057\u3066\u304a\u308a\u3001JavaScript\u306f<code>document<\/code>\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u3092\u901a\u3058\u3066\u3069\u306e\u8981\u7d20\u306b\u3082\u30a2\u30af\u30bb\u30b9\u3067\u304d\u307e\u3059\u3002CSS\u304c\u300c\u898b\u305f\u76ee\u3092\u9759\u7684\u306b\u5b9a\u7fa9\u3059\u308b\u300d\u306e\u306b\u5bfe\u3057\u3001<strong>JavaScript\u306eDOM\u64cd\u4f5c\u306f\u300c\u30da\u30fc\u30b8\u3092\u52d5\u7684\u306b\u66f8\u304d\u63db\u3048\u308b\u300d<\/strong>\u305f\u3081\u306e\u3082\u306e\u3067\u3059\u3002\u30dc\u30bf\u30f3\u3092\u62bc\u3057\u305f\u3089\u6587\u5b57\u304c\u5909\u308f\u308b\u30fb\u30b9\u30af\u30ed\u30fc\u30eb\u3067\u8981\u7d20\u304c\u73fe\u308c\u308b\u30fb\u30d5\u30a9\u30fc\u30e0\u306e\u30d0\u30ea\u30c7\u30fc\u30b7\u30e7\u30f3\u3092\u3059\u308b\u3001\u3053\u308c\u3089\u3059\u3079\u3066DOM\u3092\u4ecb\u3057\u3066\u5b9f\u73fe\u3055\u308c\u3066\u3044\u307e\u3059\u3002<\/p>\n\n<h3 class=\"wp-block-heading\">DOM\u30c4\u30ea\u30fc\u306e\u57fa\u672c\u69cb\u9020<\/h3>\n\n<p class=\"wp-block-paragraph\">DOM\u30c4\u30ea\u30fc\u306f\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u968e\u5c64\u69cb\u9020\u3092\u6301\u3061\u307e\u3059\u3002<\/p>\n\n<ul class=\"wp-block-list\">\n<li><strong>document\uff1a<\/strong>\u30da\u30fc\u30b8\u5168\u4f53\u306e\u5165\u53e3\u3068\u306a\u308b\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u3002\u3059\u3079\u3066\u306e\u64cd\u4f5c\u306f\u3053\u3053\u304b\u3089\u59cb\u307e\u308b<\/li>\n<li><strong>\u8981\u7d20\u30ce\u30fc\u30c9\uff08Element Node\uff09\uff1a<\/strong><code>&lt;h1&gt;<\/code>\u3084<code>&lt;p&gt;<\/code>\u306a\u3069\u306eHTML\u30bf\u30b0\u306b\u5bfe\u5fdc<\/li>\n<li><strong>\u30c6\u30ad\u30b9\u30c8\u30ce\u30fc\u30c9\uff08Text Node\uff09\uff1a<\/strong>\u30bf\u30b0\u306e\u4e2d\u306b\u66f8\u304b\u308c\u305f\u30c6\u30ad\u30b9\u30c8\u5185\u5bb9<\/li>\n<li><strong>\u5c5e\u6027\u30ce\u30fc\u30c9\uff08Attribute Node\uff09\uff1a<\/strong><code>id<\/code>\u3084<code>class<\/code>\u306a\u3069\u306e\u5c5e\u6027\u60c5\u5831<\/li>\n<\/ul>\n\n<p class=\"wp-block-paragraph\">JavaScript\u306eDOM\u64cd\u4f5c\u3067\u306f\u3001<strong><span class=\"swl-marker mark_yellow\">\u307e\u305a\u300c\u3069\u306e\u8981\u7d20\u3092\u64cd\u4f5c\u3059\u308b\u304b\u300d\u3092\u53d6\u5f97\u3057\u3001\u6b21\u306b\u300c\u4f55\u3092\u5909\u3048\u308b\u304b\u300d\u3092\u6307\u5b9a\u3059\u308b<\/span><\/strong>\u3068\u3044\u30462\u6bb5\u968e\u306e\u6d41\u308c\u304c\u57fa\u672c\u306b\u306a\u308a\u307e\u3059\u3002\u3053\u306e\u611f\u899a\u3055\u3048\u3064\u304b\u3081\u308c\u3070\u3001\u3042\u3068\u306f\u5fdc\u7528\u3059\u308b\u3060\u3051\u3067\u3059\u3002<\/p>\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n<h2 class=\"wp-block-heading\">\u30b9\u30c6\u30c3\u30d71\uff1a\u8981\u7d20\u3092\u53d6\u5f97\u3059\u308b4\u3064\u306e\u65b9\u6cd5<\/h2>\n\n<p class=\"wp-block-paragraph\">DOM\u64cd\u4f5c\u306e\u7b2c\u4e00\u6b69\u306f\u300c\u64cd\u4f5c\u3057\u305f\u3044\u8981\u7d20\u3092\u53d6\u5f97\u3059\u308b\u3053\u3068\u300d\u3067\u3059\u3002JavaScript\u306b\u306f\u3044\u304f\u3064\u304b\u306e\u53d6\u5f97\u30e1\u30bd\u30c3\u30c9\u304c\u7528\u610f\u3055\u308c\u3066\u3044\u307e\u3059\u3002\u73fe\u5834\u3067\u3088\u304f\u4f7f\u308f\u308c\u308b4\u3064\u3092\u62bc\u3055\u3048\u3066\u304a\u304d\u307e\u3057\u3087\u3046\u3002<\/p>\n\n<h3 class=\"wp-block-heading\">\u2460 getElementById\uff08ID\u30671\u3064\u53d6\u5f97\uff09<\/h3>\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-html\" data-lang=\"HTML\"><code>const title = document.getElementById('title');\nconsole.log(title); \/\/ &lt;h1 id=\"title\"&gt;\u306f\u3058\u3081\u3066\u306eDOM&lt;\/h1&gt;<\/code><\/pre><\/div>\n\n<p class=\"wp-block-paragraph\">\u30da\u30fc\u30b8\u5185\u306b1\u3064\u3057\u304b\u5b58\u5728\u3057\u306a\u3044ID\u3092\u6301\u3064\u8981\u7d20\u3092\u53d6\u5f97\u3059\u308b\u3068\u304d\u306b\u4f7f\u3044\u307e\u3059\u3002\u6700\u3082\u30b7\u30f3\u30d7\u30eb\u3067\u9ad8\u901f\u306a\u30e1\u30bd\u30c3\u30c9\u3067\u3059\u3002<\/p>\n\n<h3 class=\"wp-block-heading\">\u2461 querySelector\uff08CSS\u30bb\u30ec\u30af\u30bf\u30fc\u30671\u3064\u53d6\u5f97\uff09<\/h3>\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-javascript\" data-lang=\"JavaScript\"><code>const desc = document.querySelector('.description');\nconst firstLi = document.querySelector('ul li:first-child');<\/code><\/pre><\/div>\n\n<p class=\"wp-block-paragraph\"><strong><span class=\"swl-marker mark_yellow\">querySelector \u306fCSS\u30bb\u30ec\u30af\u30bf\u30fc\u3092\u305d\u306e\u307e\u307e\u4f7f\u3048\u308b\u305f\u3081\u3001\u6700\u3082\u67d4\u8edf\u6027\u304c\u9ad8\u304f\u73fe\u5834\u3067\u3082\u983b\u7e41\u306b\u4f7f\u308f\u308c\u307e\u3059\u3002<\/span><\/strong>\u30af\u30e9\u30b9\u30fb\u30bf\u30b0\u30fb\u5c5e\u6027\u30fb\u64ec\u4f3c\u30af\u30e9\u30b9\u306a\u3069\u3001CSS\u3067\u66f8\u3051\u308b\u30bb\u30ec\u30af\u30bf\u30fc\u306f\u3059\u3079\u3066\u6307\u5b9a\u53ef\u80fd\u3067\u3059\u3002<\/p>\n\n<h3 class=\"wp-block-heading\">\u2462 querySelectorAll\uff08CSS\u30bb\u30ec\u30af\u30bf\u30fc\u3067\u8907\u6570\u53d6\u5f97\uff09<\/h3>\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-javascript\" data-lang=\"JavaScript\"><code>const items = document.querySelectorAll('.list-item');\nitems.forEach(item =&gt; {\n  console.log(item.textContent);\n});<\/code><\/pre><\/div>\n\n<p class=\"wp-block-paragraph\">\u8907\u6570\u306e\u8981\u7d20\u3092\u307e\u3068\u3081\u3066\u53d6\u5f97\u3057\u305f\u3044\u5834\u5408\u306b\u4f7f\u3044\u307e\u3059\u3002\u8fd4\u308a\u5024\u306fNodeList\u3068\u3044\u3046\u914d\u5217\u306b\u4f3c\u305f\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u3067\u3001<code>forEach<\/code>\u3067\u30eb\u30fc\u30d7\u51e6\u7406\u3067\u304d\u307e\u3059\u3002<\/p>\n\n<h3 class=\"wp-block-heading\">\u2463 getElementsByClassName\u30fbgetElementsByTagName<\/h3>\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-javascript\" data-lang=\"JavaScript\"><code>const cards = document.getElementsByClassName('card');\nconst paragraphs = document.getElementsByTagName('p');<\/code><\/pre><\/div>\n\n<p class=\"wp-block-paragraph\">\u30af\u30e9\u30b9\u540d\u3084\u30bf\u30b0\u540d\u3067\u8907\u6570\u8981\u7d20\u3092\u53d6\u5f97\u3057\u307e\u3059\u3002\u8fd4\u308a\u5024\u306fHTMLCollection\u3068\u3044\u3046\u300c\u751f\u304d\u305f\u30b3\u30ec\u30af\u30b7\u30e7\u30f3\u300d\u3067\u3001DOM\u304c\u5909\u5316\u3059\u308b\u3068\u81ea\u52d5\u7684\u306b\u66f4\u65b0\u3055\u308c\u308b\u70b9\u304c\u7279\u5fb4\u3067\u3059\u3002\u305f\u3060\u3057\u73fe\u4ee3\u306e\u30b3\u30fc\u30c9\u3067\u306f<code>querySelectorAll<\/code>\u304c\u4f7f\u308f\u308c\u308b\u3053\u3068\u304c\u591a\u3044\u3067\u3059\u3002<\/p>\n\n<figure class=\"wp-block-table\"><table>\n<thead><tr><th>\u30e1\u30bd\u30c3\u30c9<\/th><th>\u53d6\u5f97\u5bfe\u8c61<\/th><th>\u8fd4\u308a\u5024<\/th><th>\u73fe\u5834\u3067\u306e\u983b\u5ea6<\/th><\/tr><\/thead>\n<tbody>\n<tr><td>getElementById<\/td><td>ID\uff081\u4ef6\uff09<\/td><td>Element<\/td><td>\u9ad8\u3044<\/td><\/tr>\n<tr><td>querySelector<\/td><td>CSS\u30bb\u30ec\u30af\u30bf\u30fc\uff081\u4ef6\u76ee\uff09<\/td><td>Element<\/td><td>\u6700\u3082\u9ad8\u3044<\/td><\/tr>\n<tr><td>querySelectorAll<\/td><td>CSS\u30bb\u30ec\u30af\u30bf\u30fc\uff08\u5168\u4ef6\uff09<\/td><td>NodeList<\/td><td>\u6700\u3082\u9ad8\u3044<\/td><\/tr>\n<tr><td>getElementsByClassName<\/td><td>\u30af\u30e9\u30b9\u540d\uff08\u5168\u4ef6\uff09<\/td><td>HTMLCollection<\/td><td>\u4e2d\u7a0b\u5ea6<\/td><\/tr>\n<tr><td>getElementsByTagName<\/td><td>\u30bf\u30b0\u540d\uff08\u5168\u4ef6\uff09<\/td><td>HTMLCollection<\/td><td>\u4f4e\u3044<\/td><\/tr>\n<\/tbody>\n<\/table><\/figure>\n\n<div class=\"wp-block-buttons is-layout-flex wp-block-buttons-is-layout-flex\">\n<div class=\"wp-block-button\"><a class=\"wp-block-button__link has-white-color has-text-color has-background has-link-color wp-element-button\" href=\"https:\/\/withcode.tech\/reservation\/\" style=\"background-color:#ffbf00\"><strong>\u516c\u5f0f\u30b5\u30a4\u30c8\u304b\u3089\u7121\u6599\u30ab\u30a6\u30f3\u30bb\u30ea\u30f3\u30b0\u306b\u7533\u3057\u8fbc\u3080 \u2192<\/strong><\/a><\/div>\n<\/div>\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n<h2 class=\"wp-block-heading\">\u30b9\u30c6\u30c3\u30d72\uff1a\u8981\u7d20\u306e\u5185\u5bb9\u30fb\u30c6\u30ad\u30b9\u30c8\u30fbHTML\u3092\u5909\u66f4\u3059\u308b<\/h2>\n\n<p class=\"wp-block-paragraph\">\u8981\u7d20\u3092\u53d6\u5f97\u3057\u305f\u3089\u3001\u6b21\u306f\u300c\u4f55\u3092\u5909\u3048\u308b\u304b\u300d\u3067\u3059\u3002\u3088\u304f\u4f7f\u3046\u30d7\u30ed\u30d1\u30c6\u30a3\u30923\u3064\u899a\u3048\u3066\u304a\u3051\u3070\u3001\u307b\u3068\u3093\u3069\u306e\u5834\u9762\u306b\u5bfe\u5fdc\u3067\u304d\u307e\u3059\u3002<\/p>\n\n<h3 class=\"wp-block-heading\">textContent\uff1a\u30c6\u30ad\u30b9\u30c8\u306e\u307f\u5909\u66f4<\/h3>\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-javascript\" data-lang=\"JavaScript\"><code>const title = document.getElementById('title');\ntitle.textContent = '\u5909\u66f4\u5f8c\u306e\u30bf\u30a4\u30c8\u30eb';<\/code><\/pre><\/div>\n\n<p class=\"wp-block-paragraph\"><code>textContent<\/code>\u306fHTML\u30bf\u30b0\u3092\u542b\u307e\u306a\u3044\u7d14\u7c8b\u306a\u30c6\u30ad\u30b9\u30c8\u3092\u8aad\u307f\u66f8\u304d\u3057\u307e\u3059\u3002<strong><span class=\"swl-marker mark_yellow\">XSS\uff08\u30af\u30ed\u30b9\u30b5\u30a4\u30c8\u30b9\u30af\u30ea\u30d7\u30c6\u30a3\u30f3\u30b0\uff09\u5bfe\u7b56\u306e\u89b3\u70b9\u304b\u3089\u3001\u30e6\u30fc\u30b6\u30fc\u5165\u529b\u3092\u305d\u306e\u307e\u307e\u8868\u793a\u3059\u308b\u5834\u5408\u306f textContent \u3092\u4f7f\u3046\u306e\u304c\u5b89\u5168\u3067\u3059\u3002<\/span><\/strong><\/p>\n\n<h3 class=\"wp-block-heading\">innerHTML\uff1aHTML\u3054\u3068\u5909\u66f4<\/h3>\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-javascript\" data-lang=\"JavaScript\"><code>const container = document.querySelector('.container');\ncontainer.innerHTML = '&lt;strong&gt;\u592a\u5b57\u306e\u30c6\u30ad\u30b9\u30c8&lt;\/strong&gt;\u304c\u8ffd\u52a0\u3055\u308c\u307e\u3057\u305f';<\/code><\/pre><\/div>\n\n<p class=\"wp-block-paragraph\"><code>innerHTML<\/code>\u306fHTML\u30bf\u30b0\u3082\u542b\u3081\u3066\u4e2d\u8eab\u3092\u66f8\u304d\u63db\u3048\u307e\u3059\u3002\u52d5\u7684\u306b\u30ea\u30b9\u30c8\u3084\u30ab\u30fc\u30c9\u3092\u751f\u6210\u3059\u308b\u3068\u304d\u306b\u4fbf\u5229\u3067\u3059\u304c\u3001\u30e6\u30fc\u30b6\u30fc\u5165\u529b\u3092\u305d\u306e\u307e\u307e\u6e21\u3059\u3068XSS\u306e\u30ea\u30b9\u30af\u304c\u3042\u308b\u305f\u3081\u6ce8\u610f\u304c\u5fc5\u8981\u3067\u3059\u3002<\/p>\n\n<h3 class=\"wp-block-heading\">value\uff1a\u5165\u529b\u30d5\u30a9\u30fc\u30e0\u306e\u5024\u3092\u8aad\u307f\u66f8\u304d<\/h3>\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-javascript\" data-lang=\"JavaScript\"><code>const input = document.querySelector('#username');\nconst value = input.value; \/\/ \u5165\u529b\u5024\u3092\u53d6\u5f97\ninput.value = '\u30c7\u30d5\u30a9\u30eb\u30c8\u5024'; \/\/ \u5024\u3092\u8a2d\u5b9a<\/code><\/pre><\/div>\n\n<p class=\"wp-block-paragraph\"><code>input<\/code>\u30fb<code>textarea<\/code>\u30fb<code>select<\/code>\u306a\u3069\u306e\u30d5\u30a9\u30fc\u30e0\u8981\u7d20\u306e\u5024\u3092\u64cd\u4f5c\u3059\u308b\u306b\u306f<code>value<\/code>\u30d7\u30ed\u30d1\u30c6\u30a3\u3092\u4f7f\u3044\u307e\u3059\u3002\u30d5\u30a9\u30fc\u30e0\u30d0\u30ea\u30c7\u30fc\u30b7\u30e7\u30f3\u3084\u5165\u529b\u88dc\u52a9UI\u3092\u4f5c\u308b\u3068\u304d\u306b\u5fc5\u9808\u306e\u77e5\u8b58\u3067\u3059\u3002<\/p>\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n<h2 class=\"wp-block-heading\">\u30b9\u30c6\u30c3\u30d73\uff1a\u30b9\u30bf\u30a4\u30eb\u3068\u30af\u30e9\u30b9\u3092JavaScript\u3067\u64cd\u4f5c\u3059\u308b<\/h2>\n\n<p class=\"wp-block-paragraph\">\u300c\u30dc\u30bf\u30f3\u3092\u62bc\u3057\u305f\u3089\u8272\u304c\u5909\u308f\u308b\u300d\u300c\u30a8\u30e9\u30fc\u6642\u306b\u8d64\u67a0\u304c\u51fa\u308b\u300d\u2014\u2014\u3053\u3046\u3057\u305f\u30a4\u30f3\u30bf\u30e9\u30af\u30b7\u30e7\u30f3\u306f\u3001\u30b9\u30bf\u30a4\u30eb\u3084\u30af\u30e9\u30b9\u3092JavaScript\u3067\u52d5\u7684\u306b\u5909\u66f4\u3059\u308b\u3053\u3068\u3067\u5b9f\u73fe\u3067\u304d\u307e\u3059\u3002<\/p>\n\n<h3 class=\"wp-block-heading\">style \u30d7\u30ed\u30d1\u30c6\u30a3\u3067\u76f4\u63a5\u30b9\u30bf\u30a4\u30eb\u3092\u5909\u66f4<\/h3>\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-javascript\" data-lang=\"JavaScript\"><code>const box = document.querySelector('.box');\nbox.style.backgroundColor = 'tomato';\nbox.style.fontSize = '20px';\nbox.style.display = 'none'; \/\/ \u975e\u8868\u793a\u306b\u3059\u308b<\/code><\/pre><\/div>\n\n<p class=\"wp-block-paragraph\">CSS\u30d7\u30ed\u30d1\u30c6\u30a3\u540d\u306f<strong>\u30ad\u30e3\u30e1\u30eb\u30b1\u30fc\u30b9\uff08camelCase\uff09<\/strong>\u3067\u6307\u5b9a\u3057\u307e\u3059\uff08\u4f8b\uff1a<code>background-color<\/code>\u2192<code>backgroundColor<\/code>\uff09\u3002\u30a4\u30f3\u30e9\u30a4\u30f3\u30b9\u30bf\u30a4\u30eb\u3068\u3057\u3066\u76f4\u63a5\u9069\u7528\u3055\u308c\u308b\u305f\u3081\u3001CSS\u306e\u8a73\u7d30\u5ea6\u304c\u9ad8\u304f\u306a\u308b\u70b9\u306b\u6ce8\u610f\u3057\u307e\u3057\u3087\u3046\u3002\u7d30\u304b\u3044\u52d5\u7684\u5909\u66f4\u306b\u306f\u5411\u3044\u3066\u3044\u307e\u3059\u304c\u3001<strong><span class=\"swl-marker mark_yellow\">\u30b9\u30bf\u30a4\u30eb\u306e\u7ba1\u7406\u306fCSS\u30af\u30e9\u30b9\u3067\u884c\u3044\u3001JavaScript\u306f\u30af\u30e9\u30b9\u306e\u4ed8\u3051\u5916\u3057\u306b\u5fb9\u3059\u308b\u8a2d\u8a08\u304c\u4fdd\u5b88\u6027\u306e\u89b3\u70b9\u304b\u3089\u63a8\u5968\u3055\u308c\u307e\u3059\u3002<\/span><\/strong><\/p>\n\n<h3 class=\"wp-block-heading\">classList \u3067\u30af\u30e9\u30b9\u3092\u64cd\u4f5c\u3059\u308b\uff08\u63a8\u5968\uff09<\/h3>\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-javascript\" data-lang=\"JavaScript\"><code>const btn = document.querySelector('.toggle-btn');\nconst menu = document.querySelector('.nav-menu');\n\n\/\/ \u30af\u30e9\u30b9\u3092\u8ffd\u52a0\nmenu.classList.add('is-open');\n\n\/\/ \u30af\u30e9\u30b9\u3092\u524a\u9664\nmenu.classList.remove('is-open');\n\n\/\/ \u30af\u30e9\u30b9\u306e\u3042\u308a\/\u306a\u3057\u3092\u5207\u308a\u66ff\u3048\uff08\u30c8\u30b0\u30eb\uff09\nmenu.classList.toggle('is-open');\n\n\/\/ \u30af\u30e9\u30b9\u304c\u5b58\u5728\u3059\u308b\u304b\u78ba\u8a8d\nif (menu.classList.contains('is-open')) {\n  console.log('\u30e1\u30cb\u30e5\u30fc\u306f\u958b\u3044\u3066\u3044\u307e\u3059');\n}<\/code><\/pre><\/div>\n\n<p class=\"wp-block-paragraph\"><code>classList<\/code>\u306e<code>add<\/code>\u30fb<code>remove<\/code>\u30fb<code>toggle<\/code>\u30fb<code>contains<\/code>\u306e4\u30e1\u30bd\u30c3\u30c9\u306f\u5b9f\u52d9\u3067\u975e\u5e38\u306b\u983b\u7e41\u306b\u4f7f\u3044\u307e\u3059\u3002\u305f\u3068\u3048\u3070\u30cf\u30f3\u30d0\u30fc\u30ac\u30fc\u30e1\u30cb\u30e5\u30fc\u306e\u958b\u9589\u30fb\u30e2\u30fc\u30c0\u30eb\u306e\u8868\u793a\u5207\u308a\u66ff\u3048\u30fb\u30bf\u30d6\u306e\u9078\u629e\u72b6\u614b\u306a\u3069\u3001\u307b\u307c\u3059\u3079\u3066\u306e\u30a4\u30f3\u30bf\u30e9\u30af\u30b7\u30e7\u30f3UI\u3067\u3053\u306e\u30d1\u30bf\u30fc\u30f3\u304c\u767b\u5834\u3057\u307e\u3059\u3002<\/p>\n\n<h3 class=\"wp-block-heading\">\u5c5e\u6027\uff08attribute\uff09\u3092\u64cd\u4f5c\u3059\u308b<\/h3>\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-javascript\" data-lang=\"JavaScript\"><code>const link = document.querySelector('a');\n\n\/\/ \u5c5e\u6027\u3092\u53d6\u5f97\nconst href = link.getAttribute('href');\n\n\/\/ \u5c5e\u6027\u3092\u8a2d\u5b9a\nlink.setAttribute('target', '_blank');\n\n\/\/ \u5c5e\u6027\u3092\u524a\u9664\nlink.removeAttribute('target');<\/code><\/pre><\/div>\n\n<p class=\"wp-block-paragraph\"><code>getAttribute<\/code>\u30fb<code>setAttribute<\/code>\u30fb<code>removeAttribute<\/code>\u3067\u4efb\u610f\u306e\u5c5e\u6027\u3092\u64cd\u4f5c\u3067\u304d\u307e\u3059\u3002<code>href<\/code>\u30fb<code>src<\/code>\u30fb<code>alt<\/code>\u30fb<code>disabled<\/code>\u306a\u3069\u3001HTML\u306e\u3042\u3089\u3086\u308b\u5c5e\u6027\u306b\u5bfe\u5fdc\u3057\u3066\u3044\u307e\u3059\u3002<\/p>\n\n<div class=\"wp-block-buttons is-layout-flex wp-block-buttons-is-layout-flex\">\n<div class=\"wp-block-button\"><a class=\"wp-block-button__link has-white-color has-text-color has-background has-link-color wp-element-button\" href=\"https:\/\/withcode.tech\/reservation\/\" style=\"background-color:#ffbf00\"><strong>\u516c\u5f0f\u30b5\u30a4\u30c8\u304b\u3089\u7121\u6599\u30ab\u30a6\u30f3\u30bb\u30ea\u30f3\u30b0\u306b\u7533\u3057\u8fbc\u3080 \u2192<\/strong><\/a><\/div>\n<\/div>\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n<h2 class=\"wp-block-heading\">\u30b9\u30c6\u30c3\u30d74\uff1a\u30a4\u30d9\u30f3\u30c8\u51e6\u7406\u3067\u30da\u30fc\u30b8\u3092\u30a4\u30f3\u30bf\u30e9\u30af\u30c6\u30a3\u30d6\u306b\u3059\u308b<\/h2>\n\n<p class=\"wp-block-paragraph\">DOM\u64cd\u4f5c\u306e\u771f\u4fa1\u3092\u767a\u63ee\u3059\u308b\u306e\u304c\u300c\u30a4\u30d9\u30f3\u30c8\u51e6\u7406\u300d\u3067\u3059\u3002\u30e6\u30fc\u30b6\u30fc\u306e\u64cd\u4f5c\uff08\u30af\u30ea\u30c3\u30af\u30fb\u5165\u529b\u30fb\u30b9\u30af\u30ed\u30fc\u30eb\u30fb\u30de\u30a6\u30b9\u30aa\u30fc\u30d0\u30fc\u306a\u3069\uff09\u3092\u30c8\u30ea\u30ac\u30fc\u306b\u3057\u3066JavaScript\u3092\u5b9f\u884c\u3059\u308b\u4ed5\u7d44\u307f\u3067\u3001<strong><span class=\"swl-marker mark_yellow\">addEventListener \u30e1\u30bd\u30c3\u30c9\u3092\u4f7f\u3046\u306e\u304c\u73fe\u4ee3\u306e\u30b9\u30bf\u30f3\u30c0\u30fc\u30c9\u306a\u66f8\u304d\u65b9\u3067\u3059\u3002<\/span><\/strong><\/p>\n\n<h3 class=\"wp-block-heading\">addEventListener \u306e\u57fa\u672c\u69cb\u6587<\/h3>\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-javascript\" data-lang=\"JavaScript\"><code>const button = document.querySelector('#my-button');\n\nbutton.addEventListener('click', function(event) {\n  console.log('\u30dc\u30bf\u30f3\u304c\u30af\u30ea\u30c3\u30af\u3055\u308c\u307e\u3057\u305f');\n  console.log(event); \/\/ \u30a4\u30d9\u30f3\u30c8\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\n});<\/code><\/pre><\/div>\n\n<p class=\"wp-block-paragraph\">\u7b2c1\u5f15\u6570\u306b\u30a4\u30d9\u30f3\u30c8\u540d\uff08\u6587\u5b57\u5217\uff09\u3001\u7b2c2\u5f15\u6570\u306b\u30b3\u30fc\u30eb\u30d0\u30c3\u30af\u95a2\u6570\uff08\u30a4\u30d9\u30f3\u30c8\u767a\u751f\u6642\u306b\u5b9f\u884c\u3055\u308c\u308b\u51e6\u7406\uff09\u3092\u6e21\u3057\u307e\u3059\u3002\u30b3\u30fc\u30eb\u30d0\u30c3\u30af\u95a2\u6570\u306b\u306f\u30a4\u30d9\u30f3\u30c8\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\uff08<code>event<\/code>\u307e\u305f\u306f<code>e<\/code>\uff09\u304c\u81ea\u52d5\u7684\u306b\u6e21\u3055\u308c\u3001\u30af\u30ea\u30c3\u30af\u4f4d\u7f6e\u30fb\u5bfe\u8c61\u8981\u7d20\u30fb\u30c7\u30d5\u30a9\u30eb\u30c8\u52d5\u4f5c\u306e\u30ad\u30e3\u30f3\u30bb\u30eb\u306a\u3069\u3092\u64cd\u4f5c\u3067\u304d\u307e\u3059\u3002<\/p>\n\n<h3 class=\"wp-block-heading\">\u3088\u304f\u4f7f\u3046\u30a4\u30d9\u30f3\u30c8\u7a2e\u985e\u4e00\u89a7<\/h3>\n\n<figure class=\"wp-block-table\"><table>\n<thead><tr><th>\u30a4\u30d9\u30f3\u30c8\u540d<\/th><th>\u767a\u751f\u30bf\u30a4\u30df\u30f3\u30b0<\/th><th>\u4e3b\u306a\u7528\u9014<\/th><\/tr><\/thead>\n<tbody>\n<tr><td>click<\/td><td>\u8981\u7d20\u3092\u30af\u30ea\u30c3\u30af\u3057\u305f\u3068\u304d<\/td><td>\u30dc\u30bf\u30f3\u30fb\u30ea\u30f3\u30af\u306e\u51e6\u7406<\/td><\/tr>\n<tr><td>input<\/td><td>\u5165\u529b\u5024\u304c\u5909\u308f\u308b\u305f\u3073\u306b<\/td><td>\u30ea\u30a2\u30eb\u30bf\u30a4\u30e0\u30d0\u30ea\u30c7\u30fc\u30b7\u30e7\u30f3<\/td><\/tr>\n<tr><td>change<\/td><td>\u5165\u529b\u304c\u78ba\u5b9a\u3057\u305f\u3068\u304d<\/td><td>\u30bb\u30ec\u30af\u30c8\u30fb\u30c1\u30a7\u30c3\u30af\u30dc\u30c3\u30af\u30b9<\/td><\/tr>\n<tr><td>submit<\/td><td>\u30d5\u30a9\u30fc\u30e0\u9001\u4fe1\u6642<\/td><td>\u9001\u4fe1\u524d\u306e\u30d0\u30ea\u30c7\u30fc\u30b7\u30e7\u30f3<\/td><\/tr>\n<tr><td>mouseover<\/td><td>\u30de\u30a6\u30b9\u304c\u8981\u7d20\u306b\u4e57\u3063\u305f\u3068\u304d<\/td><td>\u30db\u30d0\u30fc\u30a8\u30d5\u30a7\u30af\u30c8<\/td><\/tr>\n<tr><td>scroll<\/td><td>\u30b9\u30af\u30ed\u30fc\u30eb\u4e2d<\/td><td>\u30b9\u30af\u30ed\u30fc\u30eb\u9023\u52d5\u30a2\u30cb\u30e1\u30fc\u30b7\u30e7\u30f3<\/td><\/tr>\n<tr><td>DOMContentLoaded<\/td><td>HTML\u89e3\u6790\u5b8c\u4e86\u6642<\/td><td>\u521d\u671f\u5316\u51e6\u7406<\/td><\/tr>\n<\/tbody>\n<\/table><\/figure>\n\n<h3 class=\"wp-block-heading\">\u5b9f\u8df5\u4f8b\uff1a\u30af\u30ea\u30c3\u30af\u3067\u30c6\u30ad\u30b9\u30c8\u3092\u5207\u308a\u66ff\u3048\u308b\u30c8\u30b0\u30eb\u30dc\u30bf\u30f3<\/h3>\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-javascript\" data-lang=\"JavaScript\"><code>const toggleBtn = document.querySelector('#toggle-btn');\nconst message = document.querySelector('#message');\n\ntoggleBtn.addEventListener('click', () =&gt; {\n  if (message.classList.contains('is-hidden')) {\n    message.classList.remove('is-hidden');\n    toggleBtn.textContent = '\u96a0\u3059';\n  } else {\n    message.classList.add('is-hidden');\n    toggleBtn.textContent = '\u8868\u793a\u3059\u308b';\n  }\n});<\/code><\/pre><\/div>\n\n<p class=\"wp-block-paragraph\">\u3053\u308c\u306b\u5bfe\u5fdc\u3059\u308bHTML\u3068CSS\u306f\u6b21\u306e\u3068\u304a\u308a\u3067\u3059\u3002<\/p>\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-html\" data-lang=\"HTML\"><code>&lt;!-- HTML --&gt;\n&lt;button id=\"toggle-btn\"&gt;\u8868\u793a\u3059\u308b&lt;\/button&gt;\n&lt;p id=\"message\" class=\"is-hidden\"&gt;\u3053\u3093\u306b\u3061\u306f\uff01&lt;\/p&gt;\n\n&lt;!-- CSS --&gt;\n.is-hidden {\n  display: none;\n}<\/code><\/pre><\/div>\n\n<p class=\"wp-block-paragraph\"><strong><span class=\"swl-marker mark_yellow\">CSS\u306b\u300c\u72b6\u614b\u3092\u8868\u3059\u30af\u30e9\u30b9\uff08.is-open\u30fb.is-hidden\u30fb.is-active\u306a\u3069\uff09\u300d\u3092\u5b9a\u7fa9\u3057\u3066\u304a\u304d\u3001JavaScript\u306f\u305d\u306e\u30af\u30e9\u30b9\u306e\u4ed8\u3051\u5916\u3057\u3060\u3051\u3092\u62c5\u5f53\u3059\u308b\u8a2d\u8a08<\/span><\/strong>\u306f\u3001\u30b3\u30fc\u30c9\u304c\u5206\u96e2\u3055\u308c\u3066\u30e1\u30f3\u30c6\u30ca\u30f3\u30b9\u3057\u3084\u3059\u304f\u306a\u308a\u307e\u3059\u3002\u73fe\u5834\u306e\u30d7\u30ed\u3082\u610f\u8b58\u3057\u3066\u3044\u308b\u8a2d\u8a08\u30d1\u30bf\u30fc\u30f3\u3067\u3059\u3002<\/p>\n\n<h3 class=\"wp-block-heading\">\u5b9f\u8df5\u4f8b\uff1a\u30d5\u30a9\u30fc\u30e0\u306e\u30ea\u30a2\u30eb\u30bf\u30a4\u30e0\u30d0\u30ea\u30c7\u30fc\u30b7\u30e7\u30f3<\/h3>\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-javascript\" data-lang=\"JavaScript\"><code>const emailInput = document.querySelector('#email');\nconst errorMsg = document.querySelector('#email-error');\n\nemailInput.addEventListener('input', (e) =&gt; {\n  const value = e.target.value;\n  const isValid = value.includes('@');\n\n  if (isValid) {\n    errorMsg.textContent = '';\n    emailInput.classList.remove('is-error');\n  } else {\n    errorMsg.textContent = '\u6b63\u3057\u3044\u30e1\u30fc\u30eb\u30a2\u30c9\u30ec\u30b9\u3092\u5165\u529b\u3057\u3066\u304f\u3060\u3055\u3044';\n    emailInput.classList.add('is-error');\n  }\n});<\/code><\/pre><\/div>\n\n<p class=\"wp-block-paragraph\"><code>e.target<\/code>\u306f\u30a4\u30d9\u30f3\u30c8\u304c\u767a\u751f\u3057\u305f\u8981\u7d20\u81ea\u8eab\u3092\u53c2\u7167\u3057\u307e\u3059\u3002\u30d5\u30a9\u30fc\u30e0\u306e\u30d0\u30ea\u30c7\u30fc\u30b7\u30e7\u30f3\u3067\u306f\u5165\u529b\u8981\u7d20\u306e<code>value<\/code>\u3092\u53d6\u5f97\u3057\u3066\u6761\u4ef6\u5206\u5c90\u3059\u308b\u3001\u3068\u3044\u3046\u30d1\u30bf\u30fc\u30f3\u3092\u899a\u3048\u3066\u304a\u304f\u3068\u975e\u5e38\u306b\u5f79\u7acb\u3061\u307e\u3059\u3002<\/p>\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n<h2 class=\"wp-block-heading\">\u30b9\u30c6\u30c3\u30d75\uff1a\u8981\u7d20\u306e\u8ffd\u52a0\u30fb\u524a\u9664\u3067\u52d5\u7684\u306aUI\u3092\u4f5c\u308b<\/h2>\n\n<p class=\"wp-block-paragraph\">\u300c\u30dc\u30bf\u30f3\u3092\u62bc\u3057\u305f\u3089\u30ea\u30b9\u30c8\u306b\u30a2\u30a4\u30c6\u30e0\u304c\u5897\u3048\u308b\u300d\u300c\u524a\u9664\u30dc\u30bf\u30f3\u3067\u884c\u304c\u6d88\u3048\u308b\u300d\u2014\u2014\u3053\u3046\u3057\u305f\u52d5\u7684\u306aUI\u5909\u66f4\u3082\u3001DOM\u64cd\u4f5c\u306e\u91cd\u8981\u306a\u5fdc\u7528\u3067\u3059\u3002<\/p>\n\n<h3 class=\"wp-block-heading\">createElement \u3068 appendChild \u3067\u8981\u7d20\u3092\u8ffd\u52a0\u3059\u308b<\/h3>\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-javascript\" data-lang=\"JavaScript\"><code>const list = document.querySelector('#todo-list');\nconst addBtn = document.querySelector('#add-btn');\nconst inputField = document.querySelector('#todo-input');\n\naddBtn.addEventListener('click', () =&gt; {\n  const text = inputField.value.trim();\n  if (text === '') return; \/\/ \u7a7a\u306a\u3089\u51e6\u7406\u3057\u306a\u3044\n\n  \/\/ \u65b0\u3057\u3044li\u8981\u7d20\u3092\u751f\u6210\n  const li = document.createElement('li');\n  li.textContent = text;\n\n  \/\/ \u524a\u9664\u30dc\u30bf\u30f3\u3092\u8ffd\u52a0\n  const deleteBtn = document.createElement('button');\n  deleteBtn.textContent = '\u524a\u9664';\n  deleteBtn.addEventListener('click', () =&gt; {\n    li.remove(); \/\/ li\u8981\u7d20\u3054\u3068\u524a\u9664\n  });\n\n  li.appendChild(deleteBtn);\n  list.appendChild(li);\n\n  inputField.value = ''; \/\/ \u5165\u529b\u6b04\u3092\u30ea\u30bb\u30c3\u30c8\n});<\/code><\/pre><\/div>\n\n<p class=\"wp-block-paragraph\">\u3053\u306e\u30b3\u30fc\u30c9\u3060\u3051\u3067\u30b7\u30f3\u30d7\u30eb\u306aTodo\u30ea\u30b9\u30c8\u304c\u5b8c\u6210\u3057\u307e\u3059\u3002<code>createElement<\/code>\u3067\u8981\u7d20\u3092\u751f\u6210\u3057\u3001<code>appendChild<\/code>\u3067DOM\u306b\u8ffd\u52a0\u3001<code>remove<\/code>\u3067\u524a\u9664\u3068\u3044\u3046\u6d41\u308c\u306f\u3001\u3042\u3089\u3086\u308b\u52d5\u7684UI\u306e\u57fa\u790e\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n\n<h3 class=\"wp-block-heading\">insertAdjacentHTML \u3067\u7d20\u65e9\u304f\u633f\u5165\u3059\u308b<\/h3>\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-html\" data-lang=\"HTML\"><code>const container = document.querySelector('.card-container');\n\ncontainer.insertAdjacentHTML('beforeend', `\n  &lt;div class=\"card\"&gt;\n    &lt;h3&gt;\u65b0\u3057\u3044\u30ab\u30fc\u30c9&lt;\/h3&gt;\n    &lt;p&gt;\u52d5\u7684\u306b\u8ffd\u52a0\u3055\u308c\u307e\u3057\u305f&lt;\/p&gt;\n  &lt;\/div&gt;\n`);<\/code><\/pre><\/div>\n\n<p class=\"wp-block-paragraph\"><code>insertAdjacentHTML<\/code>\u306fHTML\u6587\u5b57\u5217\u3092\u6307\u5b9a\u306e\u4f4d\u7f6e\u306b\u633f\u5165\u3057\u307e\u3059\u3002<strong><span class=\"swl-marker mark_yellow\">\u30c6\u30f3\u30d7\u30ec\u30fc\u30c8\u30ea\u30c6\u30e9\u30eb\uff08\u30d0\u30c3\u30af\u30af\u30a9\u30fc\u30c8\uff09\u3068\u7d44\u307f\u5408\u308f\u305b\u308b\u3068\u3001\u8907\u6570\u8981\u7d20\u3092\u542b\u3080HTML\u30d6\u30ed\u30c3\u30af\u3092\u4e00\u6c17\u306b\u8ffd\u52a0\u3067\u304d\u308b\u305f\u3081\u3001\u30ab\u30fc\u30c9\u578bUI\u3084\u30ea\u30b9\u30c8\u8ffd\u52a0\u51e6\u7406\u3067\u7279\u306b\u4fbf\u5229\u3067\u3059\u3002<\/span><\/strong>\u633f\u5165\u4f4d\u7f6e\u306f<code>beforebegin<\/code>\u30fb<code>afterbegin<\/code>\u30fb<code>beforeend<\/code>\u30fb<code>afterend<\/code>\u306e4\u7a2e\u985e\u304b\u3089\u9078\u3079\u307e\u3059\u3002<\/p>\n\n<div class=\"wp-block-buttons is-layout-flex wp-block-buttons-is-layout-flex\">\n<div class=\"wp-block-button\"><a class=\"wp-block-button__link has-white-color has-text-color has-background has-link-color wp-element-button\" href=\"https:\/\/withcode.tech\/reservation\/\" style=\"background-color:#ffbf00\"><strong>\u516c\u5f0f\u30b5\u30a4\u30c8\u304b\u3089\u7121\u6599\u30ab\u30a6\u30f3\u30bb\u30ea\u30f3\u30b0\u306b\u7533\u3057\u8fbc\u3080 \u2192<\/strong><\/a><\/div>\n<\/div>\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n<h2 class=\"wp-block-heading\">\u3088\u304f\u3042\u308b\u5931\u6557\u3068\u305d\u306e\u5bfe\u7b56<\/h2>\n\n<p class=\"wp-block-paragraph\">DOM\u64cd\u4f5c\u3092\u5b66\u3073\u59cb\u3081\u305f\u6bb5\u968e\u3067\u3064\u307e\u305a\u304d\u3084\u3059\u3044\u30dd\u30a4\u30f3\u30c8\u3092\u307e\u3068\u3081\u307e\u3059\u3002\u30a8\u30e9\u30fc\u304c\u8d77\u304d\u305f\u3068\u304d\u306b\u307e\u305a\u3053\u3053\u3092\u78ba\u8a8d\u3057\u3066\u304f\u3060\u3055\u3044\u3002<\/p>\n\n<h3 class=\"wp-block-heading\">\u2460 \u300cnull\u300d\u30a8\u30e9\u30fc\uff1a\u8981\u7d20\u304c\u53d6\u5f97\u3067\u304d\u3066\u3044\u306a\u3044<\/h3>\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-javascript\" data-lang=\"JavaScript\"><code>\/\/ NG\uff1aHTML\u306e\u8aad\u307f\u8fbc\u307f\u524d\u306b\u30b9\u30af\u30ea\u30d7\u30c8\u304c\u5b9f\u884c\u3055\u308c\u3066\u3044\u308b\nconst btn = document.querySelector('#btn'); \/\/ null \u306b\u306a\u308b\n\n\/\/ OK1\uff1ascript\u30bf\u30b0\u3092body\u306e\u672b\u5c3e\u306b\u7f6e\u304f\n\/\/ OK2\uff1aDOMContentLoaded\u3092\u4f7f\u3046\ndocument.addEventListener('DOMContentLoaded', () =&gt; {\n  const btn = document.querySelector('#btn');\n  \/\/ \u3053\u3053\u3067\u64cd\u4f5c\u3059\u308b\n});\n\n\/\/ OK3\uff1ascript\u30bf\u30b0\u306bdefer\u5c5e\u6027\u3092\u3064\u3051\u308b\n\/\/ &lt;script src=\"main.js\" defer&gt;&lt;\/script&gt;<\/code><\/pre><\/div>\n\n<!-- withmedia-truncfix -->\n<p class=\"wp-block-paragraph\"><code>Cannot read properties of null<\/code>\u3068\u3044\u3046\u30a8\u30e9\u30fc\u306f\u3001HTML\u304c\u307e\u3060\u8aad\u307f\u8fbc\u307e\u308c\u3066\u3044\u306a\u3044\u6bb5\u968e\u3067JavaScript\u304c\u5b9f\u884c\u3055\u308c\u3001\u8981\u7d20\u3092\u53d6\u5f97\u3067\u304d\u305a\u306b<code>null<\/code>\u304c\u8fd4\u3063\u3066\u3044\u308b\u306e\u304c\u539f\u56e0\u3067\u3059\u3002\u4e0a\u306e\u3044\u305a\u308c\u304b\u306e\u65b9\u6cd5\u3067\u300cHTML\u304c\u8aad\u307f\u8fbc\u307e\u308c\u3066\u304b\u3089\u30b9\u30af\u30ea\u30d7\u30c8\u3092\u52d5\u304b\u3059\u300d\u3088\u3046\u306b\u3059\u308c\u3070\u89e3\u6c7a\u3057\u307e\u3059\u3002\u307e\u305a\u306f<code>&lt;script&gt;<\/code>\u3092<code>&lt;\/body&gt;<\/code>\u76f4\u524d\u306b\u7f6e\u304f\u304b\u3001<code>defer<\/code>\u5c5e\u6027\u3092\u4ed8\u3051\u308b\u65b9\u6cd5\u304c\u624b\u8efd\u3067\u304a\u3059\u3059\u3081\u3067\u3059\u3002<\/p>\n\n<h3 class=\"wp-block-heading\">\u2461 innerHTML\u306e\u4f7f\u3044\u3059\u304e\u3067XSS\u306e\u5371\u967a\u304c\u751f\u307e\u308c\u308b<\/h3>\n\n<p class=\"wp-block-paragraph\">\u30e6\u30fc\u30b6\u30fc\u304c\u5165\u529b\u3057\u305f\u5024\u3092<code>innerHTML<\/code>\u306b\u305d\u306e\u307e\u307e\u5165\u308c\u308b\u3068\u3001\u60aa\u610f\u3042\u308b\u30b9\u30af\u30ea\u30d7\u30c8\u304c\u5b9f\u884c\u3055\u308c\u308b\u300cXSS\uff08\u30af\u30ed\u30b9\u30b5\u30a4\u30c8\u30b9\u30af\u30ea\u30d7\u30c6\u30a3\u30f3\u30b0\uff09\u300d\u306e\u539f\u56e0\u306b\u306a\u308a\u307e\u3059\u3002\u6587\u5b57\u5217\u3092\u8868\u793a\u3057\u305f\u3044\u3060\u3051\u306a\u3089<code>textContent<\/code>\u3092\u4f7f\u3044\u3001HTML\u30bf\u30b0\u3068\u3057\u3066\u89e3\u91c8\u3055\u305b\u306a\u3044\u306e\u304c\u5b89\u5168\u3067\u3059\u3002<\/p>\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-javascript\" data-lang=\"JavaScript\"><code>const input = '&lt;img src=x onerror=alert(1)&gt;';\n\n\/\/ NG\uff1a\u5165\u529b\u5024\u3092\u305d\u306e\u307e\u307eHTML\u3068\u3057\u3066\u633f\u5165\uff08\u30b9\u30af\u30ea\u30d7\u30c8\u304c\u52d5\u304f\uff09\nbox.innerHTML = input;\n\n\/\/ OK\uff1a\u305f\u3060\u306e\u6587\u5b57\u5217\u3068\u3057\u3066\u5b89\u5168\u306b\u8868\u793a\u3059\u308b\nbox.textContent = input;<\/code><\/pre><\/div>\n\n<h3 class=\"wp-block-heading\">\u2462 getElementsByClassName\u306e\u7d50\u679c\u3092\u305d\u306e\u307e\u307eforEach\u3057\u3066\u30a8\u30e9\u30fc<\/h3>\n\n<p class=\"wp-block-paragraph\"><code>getElementsByClassName<\/code>\u3084<code>getElementsByTagName<\/code>\u304c\u8fd4\u3059\u306e\u306f\u914d\u5217\u3067\u306f\u306a\u304f\u300cHTMLCollection\u300d\u3067\u3001<code>forEach<\/code>\u304c\u4f7f\u3048\u307e\u305b\u3093\u3002<code>querySelectorAll<\/code>\u304c\u8fd4\u3059NodeList\u306f<code>forEach<\/code>\u53ef\u80fd\u3067\u3059\u304c\u3001\u78ba\u5b9f\u306b\u914d\u5217\u3068\u3057\u3066\u6271\u3044\u305f\u3044\u3068\u304d\u306f<code>Array.from()<\/code>\u3067\u5909\u63db\u3057\u307e\u3059\u3002<\/p>\n\n<div class=\"hcb_wrap\"><pre class=\"prism line-numbers lang-javascript\" data-lang=\"JavaScript\"><code>\/\/ NG\uff1aHTMLCollection\u306b\u306fforEach\u304c\u306a\u3044 \u2192 \u30a8\u30e9\u30fc\ndocument.getElementsByClassName('item').forEach(el =&gt; { ... });\n\n\/\/ OK1\uff1aquerySelectorAll\uff08NodeList\uff09\u306a\u3089forEach\u3067\u304d\u308b\ndocument.querySelectorAll('.item').forEach(el =&gt; { ... });\n\n\/\/ OK2\uff1aArray.from\u3067\u914d\u5217\u306b\u5909\u63db\u3057\u3066\u304b\u3089\u56de\u3059\nArray.from(document.getElementsByClassName('item')).forEach(el =&gt; { ... });<\/code><\/pre><\/div>\n\n<h2 class=\"wp-block-heading\">\u307e\u3068\u3081\uff1aDOM\u64cd\u4f5c\u306f\u300c\u53d6\u5f97\u2192\u5909\u66f4\u2192\u30a4\u30d9\u30f3\u30c8\u300d\u306e3\u3064\u304c\u57fa\u672c<\/h2>\n\n<p class=\"wp-block-paragraph\">JavaScript\u306eDOM\u64cd\u4f5c\u306f\u3001<strong>\u2460\u8981\u7d20\u3092\u53d6\u5f97\u3057\u3001\u2461\u5185\u5bb9\u3084\u30b9\u30bf\u30a4\u30eb\u3092\u5909\u66f4\u3057\u3001\u2462\u30a4\u30d9\u30f3\u30c8\u3067\u52d5\u304d\u3092\u3064\u3051\u308b<\/strong>\u3068\u3044\u3046\u6d41\u308c\u304c\u57fa\u672c\u3067\u3059\u3002\u3053\u306e\u8a18\u4e8b\u3067\u6271\u3063\u305f\u8981\u7d20\u306e\u53d6\u5f97\u65b9\u6cd5\u30fb\u30c6\u30ad\u30b9\u30c8\u3084\u30af\u30e9\u30b9\u306e\u5909\u66f4\u30fb\u30a4\u30d9\u30f3\u30c8\u51e6\u7406\u30fb\u8981\u7d20\u306e\u8ffd\u52a0\u524a\u9664\u3092\u62bc\u3055\u3048\u308c\u3070\u3001\u30d5\u30a9\u30fc\u30e0\u306e\u5165\u529b\u30c1\u30a7\u30c3\u30af\u3084\u30dc\u30bf\u30f3\u3067\u306e\u8868\u793a\u5207\u308a\u66ff\u3048\u306a\u3069\u3001\u5b9f\u7528\u7684\u306aUI\u306f\u3072\u3068\u901a\u308a\u4f5c\u308c\u308b\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n\n<p class=\"wp-block-paragraph\">\u6700\u521d\u306f\u3046\u307e\u304f\u52d5\u304b\u306a\u3044\u3053\u3068\u3082\u591a\u3044\u3067\u3059\u304c\u3001<code>null<\/code>\u30a8\u30e9\u30fc\u3084XSS\u3068\u3044\u3063\u305f\u3064\u307e\u305a\u304d\u30dd\u30a4\u30f3\u30c8\u306f\u3053\u306e\u8a18\u4e8b\u306e\u300c\u3088\u304f\u3042\u308b\u5931\u6557\u300d\u3092\u898b\u8fd4\u305b\u3070\u5bfe\u51e6\u3067\u304d\u307e\u3059\u3002\u307e\u305a\u306f\u5c0f\u3055\u306a\u30b5\u30f3\u30d7\u30eb\u3092\u81ea\u5206\u306e\u624b\u3067\u66f8\u3044\u3066\u52d5\u304b\u3057\u3001\u5c11\u3057\u305a\u3064\u7d44\u307f\u5408\u308f\u305b\u3066\u3044\u304d\u307e\u3057\u3087\u3046\u3002<\/p>\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<!-- withmedia-faq -->\n<h2 class=\"wp-block-heading\">\u3088\u304f\u3042\u308b\u8cea\u554f\uff08FAQ\uff09<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">Q1. DOM\u3067\u8981\u7d20\u3092\u53d6\u5f97\u3059\u308b\u306b\u306f\u3069\u306e\u30e1\u30bd\u30c3\u30c9\u3092\u4f7f\u3044\u307e\u3059\u304b\uff1f<\/h3>\n\n\n<p class=\"wp-block-paragraph\"><strong>A.<\/strong> getElementById\uff08ID\u30671\u4ef6\uff09\u3001querySelector\uff08CSS\u30bb\u30ec\u30af\u30bf\u30fc\u30671\u4ef6\u76ee\uff09\u3001querySelectorAll\uff08CSS\u30bb\u30ec\u30af\u30bf\u30fc\u3067\u5168\u4ef6\uff09\u3001getElementsByClassName\u30fbgetElementsByTagName\uff08\u30af\u30e9\u30b9\u540d\u30fb\u30bf\u30b0\u540d\u3067\u5168\u4ef6\uff09\u304c\u3042\u308a\u307e\u3059\u3002\u73fe\u5834\u3067\u306fCSS\u30bb\u30ec\u30af\u30bf\u30fc\u3092\u305d\u306e\u307e\u307e\u4f7f\u3048\u3066\u67d4\u8edf\u6027\u306e\u9ad8\u3044querySelector\u3068querySelectorAll\u304c\u6700\u3082\u3088\u304f\u4f7f\u308f\u308c\u307e\u3059\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Q2. textContent\u3068innerHTML\u306e\u9055\u3044\u306f\u4f55\u3067\u3059\u304b\uff1f<\/h3>\n\n\n<p class=\"wp-block-paragraph\"><strong>A.<\/strong> textContent\u306fHTML\u30bf\u30b0\u3092\u542b\u307e\u306a\u3044\u7d14\u7c8b\u306a\u30c6\u30ad\u30b9\u30c8\u3092\u8aad\u307f\u66f8\u304d\u3057\u3001innerHTML\u306fHTML\u30bf\u30b0\u3054\u3068\u4e2d\u8eab\u3092\u66f8\u304d\u63db\u3048\u307e\u3059\u3002innerHTML\u306f\u30e6\u30fc\u30b6\u30fc\u5165\u529b\u3092\u305d\u306e\u307e\u307e\u6e21\u3059\u3068XSS\uff08\u30af\u30ed\u30b9\u30b5\u30a4\u30c8\u30b9\u30af\u30ea\u30d7\u30c6\u30a3\u30f3\u30b0\uff09\u306e\u30ea\u30b9\u30af\u304c\u3042\u308b\u305f\u3081\u3001\u30e6\u30fc\u30b6\u30fc\u5165\u529b\u3092\u8868\u793a\u3059\u308b\u5834\u5408\u306ftextContent\u3092\u4f7f\u3046\u306e\u304c\u5b89\u5168\u3067\u3059\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Q3. \u30b9\u30bf\u30a4\u30eb\u306fstyle\u30d7\u30ed\u30d1\u30c6\u30a3\u3068classList\u306e\u3069\u3061\u3089\u3067\u5909\u66f4\u3059\u3079\u304d\u3067\u3059\u304b\uff1f<\/h3>\n\n\n<p class=\"wp-block-paragraph\"><strong>A.<\/strong> \u4fdd\u5b88\u6027\u306e\u89b3\u70b9\u304b\u3089\u306f\u3001\u30b9\u30bf\u30a4\u30eb\u306e\u7ba1\u7406\u306fCSS\u30af\u30e9\u30b9\u3067\u884c\u3044\u3001JavaScript\u306fclassList\u306eadd\u30fbremove\u30fbtoggle\u30fbcontains\u3067\u30af\u30e9\u30b9\u306e\u4ed8\u3051\u5916\u3057\u306b\u5fb9\u3059\u308b\u8a2d\u8a08\u304c\u63a8\u5968\u3055\u308c\u307e\u3059\u3002style\u30d7\u30ed\u30d1\u30c6\u30a3\u306b\u3088\u308b\u76f4\u63a5\u5909\u66f4\u306f\u8a73\u7d30\u5ea6\u304c\u9ad8\u304f\u306a\u308b\u305f\u3081\u3001\u7d30\u304b\u3044\u52d5\u7684\u5909\u66f4\u306b\u9650\u3063\u3066\u4f7f\u3046\u306e\u304c\u671b\u307e\u3057\u3044\u3067\u3059\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Q4. \u300cCannot read properties of null\u300d\u3068\u3044\u3046\u30a8\u30e9\u30fc\u306f\u306a\u305c\u8d77\u304d\u307e\u3059\u304b\uff1f<\/h3>\n\n\n<p class=\"wp-block-paragraph\"><strong>A.<\/strong> HTML\u304c\u307e\u3060\u8aad\u307f\u8fbc\u307e\u308c\u3066\u3044\u306a\u3044\u6bb5\u968e\u3067JavaScript\u304c\u5b9f\u884c\u3055\u308c\u3001\u5bfe\u8c61\u306e\u8981\u7d20\u304c\u53d6\u5f97\u3067\u304d\u3066\u3044\u306a\u3044\u3053\u3068\u304c\u4e3b\u306a\u539f\u56e0\u3067\u3059\u3002DOMContentLoaded\u30a4\u30d9\u30f3\u30c8\u3092\u4f7f\u3063\u3066\u3001HTML\u306e\u89e3\u6790\u304c\u5b8c\u4e86\u3057\u3066\u304b\u3089\u51e6\u7406\u3092\u5b9f\u884c\u3059\u308b\u3088\u3046\u306b\u3059\u308b\u3068\u9632\u3052\u307e\u3059\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Q5. \u30a4\u30d9\u30f3\u30c8\u51e6\u7406\u306f\u3069\u3046\u66f8\u304f\u306e\u304c\u73fe\u4ee3\u306e\u30b9\u30bf\u30f3\u30c0\u30fc\u30c9\u3067\u3059\u304b\uff1f<\/h3>\n\n\n<p class=\"wp-block-paragraph\"><strong>A.<\/strong> addEventListener\u30e1\u30bd\u30c3\u30c9\u3092\u4f7f\u3046\u306e\u304c\u73fe\u4ee3\u306e\u6a19\u6e96\u3067\u3059\u3002\u7b2c1\u5f15\u6570\u306b\u30a4\u30d9\u30f3\u30c8\u540d\u3001\u7b2c2\u5f15\u6570\u306b\u30b3\u30fc\u30eb\u30d0\u30c3\u30af\u95a2\u6570\u3092\u6e21\u3057\u307e\u3059\u3002click\u3084input\u3001submit\u3001DOMContentLoaded\u306a\u3069\u7528\u9014\u306b\u5fdc\u3058\u305f\u30a4\u30d9\u30f3\u30c8\u3092\u6307\u5b9a\u3067\u304d\u3001\u30b3\u30fc\u30eb\u30d0\u30c3\u30af\u306b\u306f\u30a4\u30d9\u30f3\u30c8\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u304c\u81ea\u52d5\u7684\u306b\u6e21\u3055\u308c\u307e\u3059\u3002<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<!-- withmedia-related -->\n<h2 class=\"wp-block-heading\">\u95a2\u9023\u8a18\u4e8b<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><a href=\"https:\/\/withcode.tech\/media\/engineer_hard_work\">\u3010\u30a8\u30f3\u30b8\u30cb\u30a2\u3011\u304d\u3064\u304f\u3066\u5927\u5909\uff01\u514b\u670d\u3059\u308b\u65b9\u6cd5\u3092\u89e3\u8aac\uff01<\/a><\/li>\n<li><a href=\"https:\/\/withcode.tech\/media\/web_product_develop_difference\">\u3010\u3053\u3093\u306a\u306b\u9055\u3046\uff01\u3011Web\u5236\u4f5c\u3068Web\u958b\u767a\u306e\u9055\u3044\u3092\u6bd4\u8f03\uff01<\/a><\/li>\n<li><a href=\"https:\/\/withcode.tech\/media\/web-engineer-future\/\">\u3010\u73fe\u5f79IT\u30a8\u30f3\u30b8\u30cb\u30a2\u304c\u89e3\u8aac\u3011Web\u30a8\u30f3\u30b8\u30cb\u30a2\u306e\u5c06\u6765\u306f\uff1f\u958b\u767a\u73fe\u5834\u306e\u73fe\u72b6\u3082\u5408\u308f\u305b\u3066\u89e3\u8aac\uff01<\/a><\/li>\n<li><a href=\"https:\/\/withcode.tech\/media\/wordpress-discord-integration\/\">WordPress\u3068Discord\u3092\u9023\u643a\u3055\u305b\u308b\u306b\u306f\uff1f\u52b9\u679c\u7684\u306a\u7d71\u5408\u65b9\u6cd5\u3092\u89e3\u8aac<\/a><\/li>\n<li><a href=\"https:\/\/withcode.tech\/media\/wordpress-custom-post-type\/\">WordPress\u306e\u30ab\u30b9\u30bf\u30e0\u6295\u7a3f\u3068\u306f\uff1f\u30d7\u30e9\u30b0\u30a4\u30f3\u300cCustom Post Type UI\u300d\u3067\u5b9f\u88c5\u3059\u308b\u65b9\u6cd5\u3092\u5fb9\u5e95\u89e3\u8aac\uff01<\/a><\/li>\n<li><a href=\"https:\/\/withcode.tech\/media\/javascript-array-iteration-benchmark\/\">\u3010\u5b9f\u6e2c\u3011JavaScript\u306e\u914d\u5217\u51e6\u7406\u306f\u3069\u308c\u304c\u901f\u3044\uff1fforEach\/map\/for\u6587\u3092\u30d9\u30f3\u30c1\u3057\u305f<\/a><\/li>\n<li><a href=\"https:\/\/withcode.tech\/media\/explanation-jquery-basic\/\">\u30a4\u30c1\u304b\u3089\u308f\u304b\u308bjQuery\uff01\u57fa\u790e\u304b\u3089\u5b9f\u8df5\u307e\u3067jQuery\u306e\u4f7f\u3044\u65b9\u3092\u5206\u304b\u308a\u3084\u3059\u304f\u89e3\u8aac!!<\/a><\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<!-- withmedia-references -->\n<h2 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