{"id":169346,"date":"2024-05-08T16:43:51","date_gmt":"2024-05-08T08:43:51","guid":{"rendered":"https:\/\/docs.pingcode.com\/ask\/ask-ask\/169346.html"},"modified":"2024-05-08T16:43:54","modified_gmt":"2024-05-08T08:43:54","slug":"javascript-%e5%a6%82%e4%bd%95%e5%ae%9e%e7%8e%b0-dom-%e6%a0%91%e9%81%8d%e5%8e%86","status":"publish","type":"post","link":"https:\/\/docs.pingcode.com\/ask\/ask-ask\/169346.html","title":{"rendered":"JavaScript \u5982\u4f55\u5b9e\u73b0 DOM \u6811\u904d\u5386"},"content":{"rendered":"

\"JavaScript<\/p>\n

JavaScript \u5b9e\u73b0DOM\u6811\u904d\u5386\u7684\u4e3b\u8981\u65b9\u5f0f\u5305\u62ec\u4f7f\u7528\u8282\u70b9\u95f4\u7684\u5173\u7cfb\u5c5e\u6027\u3001\u4f7f\u7528Document\u5bf9\u8c61\u7684\u67e5\u8be2\u65b9\u6cd5\u3001\u4ee5\u53ca\u4f7f\u7528\u73b0\u4ee3\u7684\u904d\u5386API\uff08\u5982TreeWalker\u548cNodeIterator\uff09<\/strong>\u3002\u8fd9\u4e9b\u65b9\u6cd5\u8ba9\u5f00\u53d1\u8005\u80fd\u591f\u4ee5\u4e0d\u540c\u65b9\u5f0f\u904d\u5386DOM\u6811\uff0c\u53ef\u4ee5\u6309\u7167\u9700\u6c42\u9009\u62e9\u9002\u5408\u7684\u904d\u5386\u7b56\u7565\u3002<\/p>\n<\/p>\n

\u5728\u8be6\u7ec6\u63cf\u8ff0\u4e4b\u524d\uff0c\u8ba9\u6211\u4eec\u5148\u805a\u7126\u4e8e\u8282\u70b9\u95f4\u7684\u5173\u7cfb\u5c5e\u6027<\/strong>\u3002\u6bcf\u4e00\u4e2aDOM\u8282\u70b9\u90fd\u5177\u6709\u4e00\u7ec4\u5c5e\u6027\uff0c\u5982parentNode\u3001childNodes\u3001firstChild\u3001lastChild\u3001nextSibling\u548cpreviousSibling\uff0c\u901a\u8fc7\u8fd9\u4e9b\u5c5e\u6027\u53ef\u4ee5\u5bf9DOM\u6811\u8fdb\u884c\u904d\u5386\u3002\u4f8b\u5982\uff0c\u901a\u8fc7\u9012\u5f52\u5730\u8bbf\u95ee\u67d0\u8282\u70b9\u7684childNodes\u5c5e\u6027\uff0c\u53ef\u4ee5\u904d\u5386\u8be5\u8282\u70b9\u7684\u6240\u6709\u5b50\u8282\u70b9\uff0c\u8fd9\u88ab\u79f0\u4e3a\u6df1\u5ea6\u4f18\u5148\u904d\u5386\uff08Depth-First Search, DFS\uff09\u3002\u501f\u52a9\u8fd9\u4e9b\u5173\u7cfb\u5c5e\u6027\uff0c\u5f00\u53d1\u8005\u53ef\u4ee5\u6784\u5efa\u51fd\u6570\u4ee5\u7279\u5b9a\u987a\u5e8f\u8bbf\u95eeDOM\u6811\u7684\u6bcf\u4e00\u4e2a\u8282\u70b9\u3002<\/p>\n<\/p>\n

\u4e00\u3001\u57fa\u4e8eDOM\u5173\u7cfb\u7684\u904d\u5386<\/strong><\/p>\n<\/p>\n

\u6df1\u5ea6\u4f18\u5148\u904d\u5386\uff08Depth-First Search, DFS\uff09\u548c\u5bbd\u5ea6\u4f18\u5148\u904d\u5386\uff08Breadth-First Search, BFS\uff09\u662f\u4e24\u79cd\u6700\u57fa\u672c\u7684DOM\u904d\u5386\u65b9\u6cd5\u3002\u6df1\u5ea6\u4f18\u5148\u904d\u5386\u610f\u5473\u7740\u6211\u4eec\u5148\u904d\u5386\u6240\u6709\u5b50\u6811\uff0c\u7136\u540e\u518d\u79fb\u81f3\u5144\u5f1f\u8282\u70b9\uff0c\u800c\u5bbd\u5ea6\u4f18\u5148\u904d\u5386\u5219\u610f\u5473\u7740\u6211\u4eec\u5148\u8bbf\u95ee\u540c\u4e00\u5c42\u7ea7\u7684\u6240\u6709\u8282\u70b9\uff0c\u518d\u8bbf\u95ee\u4e0b\u4e00\u5c42\u7ea7\u7684\u8282\u70b9\u3002<\/p>\n<\/p>\n

\u6df1\u5ea6\u4f18\u5148\u904d\u5386<\/strong><\/p>\n<\/p>\n

\u8981\u5b9e\u73b0\u6df1\u5ea6\u4f18\u5148\u904d\u5386\uff0c\u901a\u5e38\u91c7\u7528\u9012\u5f52\u65b9\u6cd5\u3002\u4ee5\u4e0b\u662f\u4e00\u4e2a\u4f7f\u7528\u9012\u5f52\u7684\u6df1\u5ea6\u4f18\u5148\u904d\u5386DOM\u6811\u7684\u57fa\u672c\u793a\u4f8b\uff1a<\/p>\n<\/p>\n

function traverseDFS(node) {<\/p>\n
  if (node) {<\/p>\n
    console.log(node); \/\/ \u5904\u7406\u5f53\u524d\u8282\u70b9<\/p>\n
    var children = node.childNodes;<\/p>\n
    for (var i = 0; i < children.length; i++) {<\/p>\n
      traverseDFS(children[i]); \/\/ \u9012\u5f52\u904d\u5386\u6240\u6709\u5b50\u8282\u70b9<\/p>\n
    }<\/p>\n
  }<\/p>\n
}<\/p>\n
traverseDFS(document.body); \/\/ \u4ece<body>\u6807\u7b7e\u5f00\u59cb\u904d\u5386<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u5bbd\u5ea6\u4f18\u5148\u904d\u5386<\/strong><\/p>\n<\/p>\n
\u5bbd\u5ea6\u4f18\u5148\u904d\u5386\u5219\u9700\u8981\u4f7f\u7528\u961f\u5217\u6765\u5b9e\u73b0\uff0c\u4ee5\u4e0b\u662f\u4e00\u4e2a\u5bbd\u5ea6\u4f18\u5148\u904d\u5386DOM\u6811\u7684\u57fa\u672c\u793a\u4f8b\uff1a<\/p>\n<\/p>\n
function traverseBFS(root) {<\/p>\n
  let queue = [root]; \/\/ \u521d\u59cb\u5316\u961f\u5217<\/p>\n
  while (queue.length) {<\/p>\n
    const node = queue.shift(); \/\/ \u53d6\u51fa\u961f\u5217\u7684\u7b2c\u4e00\u4e2a\u8282\u70b9<\/p>\n
    console.log(node); \/\/ \u5904\u7406\u5f53\u524d\u8282\u70b9<\/p>\n
    var children = node.childNodes;<\/p>\n
    for (var i = 0; i < children.length; i++) {<\/p>\n
      queue.push(children[i]); \/\/ \u5c06\u5b50\u8282\u70b9\u52a0\u5165\u961f\u5217<\/p>\n
    }<\/p>\n
  }<\/p>\n
}<\/p>\n
traverseBFS(document.body); \/\/ \u4ece<body>\u6807\u7b7e\u5f00\u59cb\u904d\u5386<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u4e8c\u3001Document\u5bf9\u8c61\u7684\u67e5\u8be2\u65b9\u6cd5<\/strong><\/p>\n<\/p>\n
\u9664\u4e86\u4f7f\u7528\u8282\u70b9\u95f4\u7684\u5173\u7cfb\u5c5e\u6027\uff0c\u4e3a\u4e86\u4fbf\u6377\u5730\u67e5\u627e\u5143\u7d20\uff0cDOM\u4e2d\u7684Document\u5bf9\u8c61\u63d0\u4f9b\u4e86\u591a\u4e2a\u67e5\u8be2\u65b9\u6cd5\u3002<\/p>\n<\/p>\n
\u83b7\u53d6\u7279\u5b9a\u5143\u7d20<\/strong><\/p>\n<\/p>\n
getElementById<\/code>\u662f\u6700\u57fa\u672c\u7684\u65b9\u6cd5\uff0c\u7528\u6765\u6839\u636eID\u83b7\u53d6\u7279\u5b9a\u7684\u5143\u7d20\u3002<\/p>\n<\/p>\n
var element = document.getElementById("unique-id");<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u83b7\u53d6\u7b26\u5408\u7279\u5b9a\u6761\u4ef6\u7684\u5143\u7d20\u96c6\u5408<\/strong><\/p>\n<\/p>\n
getElementsByTagName<\/code>\u548cgetElementsByClassName<\/code>\u7528\u4e8e\u6839\u636e\u6807\u7b7e\u540d\u548c\u7c7b\u540d\u83b7\u53d6DOM\u5143\u7d20\u7684\u96c6\u5408\u3002<\/p>\n<\/p>\n
var elementsByTagName = document.getElementsByTagName("div");<\/p>\n
var elementsByClassName = document.getElementsByClassName("some-class");<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u4f7f\u7528CSS\u9009\u62e9\u5668\u68c0\u7d22\u5143\u7d20<\/strong><\/p>\n<\/p>\n
\u66f4\u5f3a\u5927\u548c\u7075\u6d3b\u7684\u65b9\u6cd5\u662fquerySelector<\/code>\u548cquerySelectorAll<\/code>\uff0c\u5b83\u4eec\u5141\u8bb8\u4f7f\u7528CSS\u9009\u62e9\u5668\u8bed\u6cd5\u6765\u67e5\u627e\u5339\u914d\u7684\u5355\u4e2a\u5143\u7d20\u6216\u5143\u7d20\u96c6\u5408\u3002<\/p>\n<\/p>\n
var firstMatch = document.querySelector(".some-class");<\/p>\n
var allMatches = document.querySelectorAll("ul > li.some-class");<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u4e09\u3001\u73b0\u4ee3\u7684\u904d\u5386API<\/strong><\/p>\n<\/p>\n
\u73b0\u4ee3\u6d4f\u89c8\u5668\u63d0\u4f9b\u4e86\u4e13\u95e8\u7684\u904d\u5386API\uff0c\u5141\u8bb8\u66f4\u7075\u6d3b\u5730\u904d\u5386DOM\u6811\u3002<\/p>\n<\/p>\n
TreeWalker<\/strong><\/p>\n<\/p>\n
TreeWalker \u662f\u4e00\u4e2a\u6784\u9020\u51fd\u6570\uff0c\u5b83\u63d0\u4f9b\u4e86\u5bf9DOM\u6811\u7684\u8282\u70b9\u8fdb\u884c\u8fc7\u6ee4\u548c\u904d\u5386\u7684\u65b9\u6cd5\u3002<\/p>\n<\/p>\n
var treeWalker = document.createTreeWalker(<\/p>\n
  document.body, <\/p>\n
  NodeFilter.SHOW_ELEMENT,  \/\/ \u8fc7\u6ee4\u5668\uff0c\u8fd9\u91cc\u6307\u793a\u53ea\u8fd4\u56de\u5143\u7d20\u8282\u70b9<\/p>\n
  { acceptNode: function(node) { return NodeFilter.FILTER_ACCEPT; } }, <\/p>\n
  false<\/p>\n
);<\/p>\n
while (treeWalker.nextNode()) {<\/p>\n
    console.log(treeWalker.currentNode); \/\/ \u4f9d\u6b21\u8bbf\u95ee\u6bcf\u4e2a\u7b26\u5408\u6761\u4ef6\u7684\u8282\u70b9<\/p>\n
}<\/p>\n
<\/code><\/pre>\n<\/p>\n
NodeIterator<\/strong><\/p>\n<\/p>\n
\u7c7b\u4f3c\u4e8eTreeWalker\uff0cNodeIterator\u4e5f\u662f\u7528\u4e8e\u904d\u5386DOM\u8282\u70b9\u3002\u4e0d\u540c\u4e4b\u5904\u5728\u4e8eNodeIterator\u7684\u904d\u5386\u4e0d\u4f1a\u5f71\u54cd\u5230\u539f\u59cb\u7684DOM\u7ed3\u6784\u3002<\/p>\n<\/p>\n
var nodeIterator = document.createNodeIterator(<\/p>\n
  document.body, <\/p>\n
  NodeFilter.SHOW_ELEMENT<\/p>\n
);<\/p>\n
var currentNode;<\/p>\n
while (currentNode = nodeIterator.nextNode()) {<\/p>\n
    console.log(currentNode); \/\/ \u4f9d\u6b21\u8bbf\u95ee\u6bcf\u4e2a\u7b26\u5408\u6761\u4ef6\u7684\u8282\u70b9<\/p>\n
}<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u4ee5\u4e0a\u4ecb\u7ecd\u7684\u662fJavaScript\u4e2d\u5b9e\u73b0DOM\u6811\u904d\u5386\u7684\u51e0\u79cd\u4e3b\u8981\u65b9\u6cd5\uff0c\u5f00\u53d1\u8005\u53ef\u4ee5\u6839\u636e\u5177\u4f53\u60c5\u5f62\u6311\u9009\u5408\u9002\u7684\u65b9\u5f0f\u3002\u968f\u7740JavaScript\u8bed\u8a00\u7684\u4e0d\u65ad\u6f14\u5316\uff0c\u53ef\u80fd\u8fd8\u4f1a\u6709\u65b0\u7684\u65b9\u6cd5\u51fa\u73b0\uff0c\u4f46\u6838\u5fc3\u539f\u7406\u4ecd\u7136\u662f\u904d\u5386DOM\u6811\u8fd9\u4e2a\u6570\u636e\u7ed3\u6784\u3002\u5728\u5f00\u53d1\u8fc7\u7a0b\u4e2d\u5408\u7406\u5229\u7528\u8fd9\u4e9b\u65b9\u6cd5\u5c06\u6781\u5927\u63d0\u9ad8\u5bf9DOM\u64cd\u4f5c\u7684\u6548\u7387\u548c\u6027\u80fd\u3002<\/p>\n<\/p>\n
\u76f8\u5173\u95ee\u7b54FAQs\uff1a<\/strong><\/h2>\n
\u5982\u4f55\u4f7f\u7528 JavaScript \u904d\u5386 DOM \u6811\uff1f<\/strong><\/p>\n
DOM \u6811\u904d\u5386\uff1aJavaScript \u4e2d\u7684\u51e0\u79cd\u65b9\u6cd5<\/strong><\/p>\n
JavaScript \u4e2d\u5982\u4f55\u4f7f\u7528\u9012\u5f52\u5b9e\u73b0 DOM \u6811\u7684\u904d\u5386\uff1f<\/strong><\/p>\n","protected":false},"excerpt":{"rendered":"JavaScript \u5b9e\u73b0DOM\u6811\u904d\u5386\u7684\u4e3b\u8981\u65b9\u5f0f\u5305\u62ec\u4f7f\u7528\u8282\u70b9\u95f4\u7684\u5173\u7cfb\u5c5e\u6027\u3001\u4f7f\u7528Document\u5bf9\u8c61\u7684\u67e5\u8be2\u65b9\u6cd5\u3001 […]","protected":false},"author":3,"featured_media":169351,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[37],"tags":[],"acf":[],"_links":{"self":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts\/169346"}],"collection":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/comments?post=169346"}],"version-history":[{"count":0,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts\/169346\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/media\/169351"}],"wp:attachment":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/media?parent=169346"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/categories?post=169346"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/tags?post=169346"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}