{"id":2114,"date":"2025-02-27T23:52:17","date_gmt":"2025-02-27T15:52:17","guid":{"rendered":"https:\/\/www.laixuexila.com\/?p=2114"},"modified":"2025-02-27T23:52:17","modified_gmt":"2025-02-27T15:52:17","slug":"javascript-html-dom-%e9%9b%86%e5%90%88-collection","status":"publish","type":"post","link":"https:\/\/www.laixuexila.com\/index.php\/2025\/02\/27\/javascript-html-dom-%e9%9b%86%e5%90%88-collection\/","title":{"rendered":"JavaScript HTML DOM \u96c6\u5408 (Collection)"},"content":{"rendered":"\n

\u5728 JavaScript \u4e2d\uff0cDOM \u96c6\u5408\uff08Collection\uff09\u662f\u7531\u591a\u4e2a DOM \u5143\u7d20\uff08\u8282\u70b9\uff09\u7ec4\u6210\u7684\u5bf9\u8c61\u3002\u5b83\u4eec\u901a\u5e38\u662f\u7531\u67e5\u8be2\u65b9\u6cd5\u8fd4\u56de\u7684\uff0c\u5e76\u5141\u8bb8\u6211\u4eec\u4ee5\u67d0\u79cd\u65b9\u5f0f\u8bbf\u95ee\u4e00\u7ec4 DOM \u5143\u7d20\u3002\u96c6\u5408\u5bf9\u8c61\u901a\u5e38\u662f\u7c7b\u6570\u7ec4\u7684\u5bf9\u8c61\uff0c\u4f46\u4e0e\u6570\u7ec4\u4e0d\u540c\uff0c\u5b83\u4eec\u6ca1\u6709\u6570\u7ec4\u7684\u4e00\u4e9b\u65b9\u6cd5\uff08\u5982 map<\/code>\u3001filter<\/code> \u7b49\uff09\u3002DOM \u96c6\u5408\u6700\u5e38\u89c1\u7684\u4f8b\u5b50\u662f\u901a\u8fc7 getElementsByClassName()<\/code>\u3001getElementsByTagName()<\/code> \u548c querySelectorAll()<\/code> \u7b49\u65b9\u6cd5\u8fd4\u56de\u7684\u3002<\/p>\n\n\n\n

1. DOM \u96c6\u5408\u7684\u79cd\u7c7b<\/strong><\/h3>\n\n\n\n

\u5e38\u89c1\u7684 DOM \u96c6\u5408\u7c7b\u578b\u5305\u62ec\uff1a<\/p>\n\n\n\n

    \n
  • HTMLCollection<\/code><\/strong>\uff1a\u4e00\u4e2a\u201c\u6d3b\u7684\u201d\u96c6\u5408\uff0c\u5373\u5982\u679c DOM \u4e2d\u7684\u5143\u7d20\u53d1\u751f\u53d8\u5316\uff0c\u96c6\u5408\u4e5f\u4f1a\u81ea\u52a8\u66f4\u65b0\u3002<\/li>\n\n\n\n
  • NodeList<\/code><\/strong>\uff1a\u7c7b\u4f3c\u6570\u7ec4\u7684\u96c6\u5408\uff0c\u5305\u542b\u6240\u6709\u7b26\u5408\u6761\u4ef6\u7684\u8282\u70b9\uff0c\u901a\u5e38\u7531 querySelectorAll()<\/code> \u8fd4\u56de\u3002\u5b83\u662f\u9759\u6001\u7684\uff0c\u4e5f\u5c31\u662f\u8bf4\uff0c\u5982\u679c DOM \u4e2d\u7684\u5143\u7d20\u53d1\u751f\u53d8\u5316\uff0cNodeList \u4e0d\u4f1a\u81ea\u52a8\u66f4\u65b0\u3002<\/li>\n<\/ul>\n\n\n\n

    2. HTMLCollection<\/code><\/strong><\/h3>\n\n\n\n

    HTMLCollection<\/code> \u662f\u7531 DOM \u67e5\u8be2\u65b9\u6cd5\uff08\u5982 getElementsByClassName()<\/code> \u548c getElementsByTagName()<\/code>\uff09\u8fd4\u56de\u7684\u4e00\u4e2a\u96c6\u5408\u3002\u5b83\u662f\u4e00\u4e2a\u201c\u6d3b\u7684\u201d\u96c6\u5408\uff0c\u610f\u5473\u7740 DOM \u4e2d\u7684\u5143\u7d20\u53d1\u751f\u53d8\u5316\u65f6\uff0cHTMLCollection<\/code> \u4f1a\u81ea\u52a8\u66f4\u65b0\u3002<\/p>\n\n\n\n

    \u5e38\u7528\u65b9\u6cd5\uff1a<\/strong><\/h4>\n\n\n\n
      \n
    • length<\/code><\/strong>\uff1a\u8fd4\u56de\u96c6\u5408\u4e2d\u7684\u5143\u7d20\u6570\u91cf\u3002<\/li>\n\n\n\n
    • item(index)<\/code><\/strong>\uff1a\u901a\u8fc7\u7d22\u5f15\u83b7\u53d6\u96c6\u5408\u4e2d\u7684\u5143\u7d20\u3002<\/li>\n<\/ul>\n\n\n\n

      \u793a\u4f8b\uff1a<\/strong><\/h4>\n\n\n\n
      <div class=\"item\">Item 1<\/div>\n<div class=\"item\">Item 2<\/div>\n<div class=\"item\">Item 3<\/div>\n\n<script>\n  const items = document.getElementsByClassName(\"item\");\n  console.log(items.length);  \/\/ \u8f93\u51fa 3\n\n  \/\/ \u8bbf\u95ee\u7b2c\u4e00\u4e2a\u5143\u7d20\n  console.log(items[0].innerHTML);  \/\/ \u8f93\u51fa \"Item 1\"\n\n  \/\/ \u904d\u5386\u96c6\u5408\n  for (let i = 0; i < items.length; i++) {\n    console.log(items[i].innerHTML);\n  }\n<\/script><\/code><\/pre>\n\n\n\n
      \u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0citems<\/code> \u662f\u4e00\u4e2a HTMLCollection<\/code>\uff0c\u5b83\u5305\u542b\u4e86\u6240\u6709\u7c7b\u540d\u4e3a \"item\"<\/code> \u7684 div<\/code> \u5143\u7d20\u3002\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528\u7d22\u5f15\u8bbf\u95ee\u6bcf\u4e2a\u5143\u7d20\u3002<\/p>\n\n\n\n
      3. NodeList<\/code><\/strong><\/h3>\n\n\n\n
      NodeList<\/code> \u662f\u7531 querySelectorAll()<\/code> \u548c\u5176\u4ed6\u4e00\u4e9b\u65b9\u6cd5\uff08\u5982 childNodes<\/code>\uff09\u8fd4\u56de\u7684\u96c6\u5408\u3002\u4e0e HTMLCollection<\/code> \u4e0d\u540c\uff0cNodeList<\/code> \u662f\u9759\u6001\u7684\uff0c\u8fd9\u610f\u5473\u7740\u5b83\u4e0d\u4f1a\u968f DOM \u66f4\u65b0\u800c\u81ea\u52a8\u6539\u53d8\u3002<\/p>\n\n\n\n
      \u5e38\u7528\u65b9\u6cd5\uff1a<\/strong><\/h4>\n\n\n\n
        \n
      • length<\/code><\/strong>\uff1a\u8fd4\u56de\u96c6\u5408\u4e2d\u7684\u8282\u70b9\u6570\u91cf\u3002<\/li>\n\n\n\n
      • item(index)<\/code><\/strong>\uff1a\u901a\u8fc7\u7d22\u5f15\u83b7\u53d6\u96c6\u5408\u4e2d\u7684\u8282\u70b9\u3002<\/li>\n\n\n\n
      • forEach()<\/code><\/strong>\uff1aNodeList<\/code> \u53ef\u4ee5\u4f7f\u7528 forEach()<\/code> \u65b9\u6cd5\u8fdb\u884c\u904d\u5386\uff08\u4ec5\u5728\u67d0\u4e9b\u60c5\u51b5\u4e0b\u6709\u6548\uff0c\u7279\u522b\u662f querySelectorAll()<\/code> \u8fd4\u56de\u7684 NodeList<\/code>\uff09\u3002<\/li>\n<\/ul>\n\n\n\n
        \u793a\u4f8b\uff1a<\/strong><\/h4>\n\n\n\n
        <div id=\"parent\">\n  <p class=\"child\">Child 1<\/p>\n  <p class=\"child\">Child 2<\/p>\n  <p class=\"child\">Child 3<\/p>\n<\/div>\n\n<script>\n  const children = document.querySelectorAll(\".child\");\n  console.log(children.length);  \/\/ \u8f93\u51fa 3\n\n  \/\/ \u4f7f\u7528 forEach \u904d\u5386 NodeList\n  children.forEach(function(child) {\n    console.log(child.innerHTML);  \/\/ \u8f93\u51fa \"Child 1\", \"Child 2\", \"Child 3\"\n  });\n<\/script><\/code><\/pre>\n\n\n\n
        \u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0cchildren<\/code> \u662f\u4e00\u4e2a NodeList<\/code>\uff0c\u5b83\u5305\u542b\u4e86\u6240\u6709\u7c7b\u540d\u4e3a \"child\"<\/code> \u7684 <p><\/code> \u5143\u7d20\u3002\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528 forEach()<\/code> \u65b9\u6cd5\u6765\u904d\u5386 NodeList<\/code> \u4e2d\u7684\u6bcf\u4e2a\u5143\u7d20\u3002<\/p>\n\n\n\n
        4. NodeList<\/code> \u548c HTMLCollection<\/code> \u7684\u533a\u522b<\/strong><\/h3>\n\n\n\n
          \n
        • \u66f4\u65b0\u65b9\u5f0f<\/strong>\uff1aHTMLCollection<\/code> \u662f\u201c\u6d3b\u7684\u201d\uff0c\u5373\u5b83\u4f1a\u968f\u7740 DOM \u7684\u53d8\u5316\u81ea\u52a8\u66f4\u65b0\uff1b\u800c NodeList<\/code> \u901a\u5e38\u662f\u9759\u6001\u7684\uff0c\u9664\u975e\u5b83\u662f\u7531 querySelectorAll()<\/code> \u65b9\u6cd5\u8fd4\u56de\u7684\u3002<\/li>\n\n\n\n
        • \u904d\u5386\u65b9\u6cd5<\/strong>\uff1aHTMLCollection<\/code> \u53ea\u80fd\u4f7f\u7528\u4f20\u7edf\u7684 for<\/code> \u5faa\u73af\u904d\u5386\uff0c\u4e0d\u80fd\u76f4\u63a5\u4f7f\u7528 forEach()<\/code>\uff0c\u4f46 NodeList<\/code> \uff08\u7279\u522b\u662f\u7531 querySelectorAll()<\/code> \u8fd4\u56de\u7684\uff09\u53ef\u4ee5\u4f7f\u7528 forEach()<\/code> \u65b9\u6cd5\u3002<\/li>\n<\/ul>\n\n\n\n
          5. \u8f6c\u6362 HTMLCollection<\/code> \u4e3a\u6570\u7ec4<\/strong><\/h3>\n\n\n\n
          \u867d\u7136 HTMLCollection<\/code> \u548c NodeList<\/code> \u662f\u7c7b\u6570\u7ec4\u5bf9\u8c61\uff0c\u4f46\u5b83\u4eec\u5e76\u4e0d\u5177\u5907\u6570\u7ec4\u7684\u65b9\u6cd5\uff08\u5982 map<\/code>\u3001filter<\/code>\uff09\u3002\u5982\u679c\u9700\u8981\u4f7f\u7528\u8fd9\u4e9b\u65b9\u6cd5\uff0c\u53ef\u4ee5\u5c06 HTMLCollection<\/code> \u6216 NodeList<\/code> \u8f6c\u6362\u4e3a\u771f\u6b63\u7684\u6570\u7ec4\u3002<\/p>\n\n\n\n
          \u793a\u4f8b\uff1a<\/strong><\/h4>\n\n\n\n
          <div class=\"item\">Item 1<\/div>\n<div class=\"item\">Item 2<\/div>\n<div class=\"item\">Item 3<\/div>\n\n<script>\n  const items = document.getElementsByClassName(\"item\");\n\n  \/\/ \u5c06 HTMLCollection \u8f6c\u6362\u4e3a\u6570\u7ec4\n  const itemsArray = Array.from(items);\n\n  \/\/ \u73b0\u5728\u53ef\u4ee5\u4f7f\u7528\u6570\u7ec4\u65b9\u6cd5\n  itemsArray.forEach(function(item) {\n    console.log(item.innerHTML);  \/\/ \u8f93\u51fa \"Item 1\", \"Item 2\", \"Item 3\"\n  });\n<\/script><\/code><\/pre>\n\n\n\n
          \u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0cArray.from()<\/code> \u65b9\u6cd5\u5c06 HTMLCollection<\/code> \u8f6c\u6362\u4e3a\u6570\u7ec4\uff0c\u7136\u540e\u53ef\u4ee5\u4f7f\u7528\u6570\u7ec4\u7684 forEach()<\/code> \u65b9\u6cd5\u6765\u904d\u5386\u6bcf\u4e2a\u5143\u7d20\u3002<\/p>\n\n\n\n
          6. \u603b\u7ed3<\/strong><\/h3>\n\n\n\n
            \n
          • HTMLCollection<\/code><\/strong> \u548c NodeList<\/code><\/strong> \u90fd\u662f\u7531 DOM \u65b9\u6cd5\u8fd4\u56de\u7684\u96c6\u5408\uff0c\u5b83\u4eec\u5305\u542b\u591a\u4e2a DOM \u5143\u7d20\u6216\u8282\u70b9\u3002<\/li>\n\n\n\n
          • HTMLCollection<\/code><\/strong> \u662f\u4e00\u4e2a\u201c\u6d3b\u7684\u201d\u96c6\u5408\uff0c\u4f1a\u968f\u7740 DOM \u53d8\u5316\u800c\u81ea\u52a8\u66f4\u65b0\uff1b\u800c NodeList<\/code><\/strong> \u901a\u5e38\u662f\u9759\u6001\u7684\u3002<\/li>\n\n\n\n
          • NodeList<\/code><\/strong> \u53ef\u4ee5\u4f7f\u7528 forEach()<\/code> \u65b9\u6cd5\u6765\u904d\u5386\uff0c\u800c HTMLCollection<\/code><\/strong> \u4e0d\u80fd\u76f4\u63a5\u4f7f\u7528\u3002<\/li>\n\n\n\n
          • \u53ef\u4ee5\u901a\u8fc7 Array.from()<\/code> \u6216\u6269\u5c55\u8fd0\u7b97\u7b26 ...<\/code> \u5c06 HTMLCollection<\/code><\/strong> \u6216 NodeList<\/code><\/strong> \u8f6c\u6362\u4e3a\u6570\u7ec4\uff0c\u4ece\u800c\u4f7f\u7528\u6570\u7ec4\u65b9\u6cd5\u3002<\/li>\n<\/ul>\n\n\n\n
            \u901a\u8fc7\u4e86\u89e3 DOM \u96c6\u5408\uff0c\u6211\u4eec\u53ef\u4ee5\u7075\u6d3b\u5730\u64cd\u4f5c\u548c\u904d\u5386\u7f51\u9875\u4e2d\u7684\u5143\u7d20\uff0c\u63d0\u5347\u7f51\u9875\u4ea4\u4e92\u6027\u3002<\/p>\n\n\n\n
            \u66f4\u591a\u8be6\u7ec6\u5185\u5bb9\u8bf7\u5173\u6ce8\u5176\u4ed6\u76f8\u5173\u6587\u7ae0\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
            \u5728 JavaScript \u4e2d\uff0cDOM \u96c6\u5408\uff08Collection\uff09\u662f\u7531\u591a\u4e2a DOM \u5143\u7d20\uff08\u8282\u70b9\uff09\u7ec4\u6210\u7684\u5bf9\u8c61\u3002\u5b83 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[46],"tags":[],"class_list":["post-2114","post","type-post","status-publish","format-standard","hentry","category-javascript"],"_links":{"self":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/2114","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/comments?post=2114"}],"version-history":[{"count":1,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/2114\/revisions"}],"predecessor-version":[{"id":2115,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/2114\/revisions\/2115"}],"wp:attachment":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/media?parent=2114"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/categories?post=2114"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/tags?post=2114"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}