{"id":168462,"date":"2024-05-08T16:24:12","date_gmt":"2024-05-08T08:24:12","guid":{"rendered":"https:\/\/docs.pingcode.com\/ask\/ask-ask\/168462.html"},"modified":"2024-05-08T16:24:22","modified_gmt":"2024-05-08T08:24:22","slug":"javascript-%e6%80%8e%e4%b9%88%e8%8e%b7%e5%8f%96-id-%e5%b1%9e%e6%80%a7","status":"publish","type":"post","link":"https:\/\/docs.pingcode.com\/ask\/168462.html","title":{"rendered":"JavaScript \u600e\u4e48\u83b7\u53d6 id \u5c5e\u6027"},"content":{"rendered":"

\"JavaScript<\/p>\n

\u83b7\u53d6\u5143\u7d20\u7684ID\u5c5e\u6027\u5728JavaScript\u5f00\u53d1\u4e2d\u662f\u4e00\u9879\u57fa\u672c\u800c\u91cd\u8981\u7684\u6280\u80fd\u3002\u4e3b\u8981\u7684\u65b9\u6cd5\u6709getElementById<\/code>\u548cquerySelector<\/code><\/strong>\uff0c\u5b83\u4eec\u90fd\u53ef\u4ee5\u7528\u4e8e\u83b7\u53d6\u5177\u6709\u7279\u5b9aID\u7684DOM\u5143\u7d20\u3002\u5176\u4e2d\uff0cgetElementById<\/code>\u662f\u6700\u76f4\u63a5\u3001\u6700\u5feb\u901f\u7684\u65b9\u6cd5\uff0c\u5b83\u76f4\u63a5\u6839\u636e\u5143\u7d20\u7684ID\u503c\u8fdb\u884c\u67e5\u627e\u5e76\u8fd4\u56de\u5bf9\u5e94\u7684DOM\u5bf9\u8c61\u3002\u8fd9\u79cd\u65b9\u6cd5\u7684\u6548\u7387\u975e\u5e38\u9ad8\uff0c\u56e0\u4e3a\u6d4f\u89c8\u5668\u5185\u90e8\u5bf9ID\u503c\u6709\u4f18\u5316\u5904\u7406\u3002getElementById<\/code>\u7684\u4f7f\u7528\u975e\u5e38\u7b80\u5355\uff0c\u53ea\u9700\u8981\u5c06\u76ee\u6807\u5143\u7d20\u7684ID\u4f5c\u4e3a\u53c2\u6570\u4f20\u9012\u7ed9\u8fd9\u4e2a\u51fd\u6570\u5373\u53ef\u3002<\/p>\n<\/p>\n

\u4e00\u3001GETELEMENTBYID\u65b9\u6cd5<\/h3>\n<\/p>\n

getElementById<\/code>\u65b9\u6cd5\u662fDOM\u7f16\u7a0b\u4e2d\u6700\u5e38\u7528\u7684\u5de5\u5177\u4e4b\u4e00\uff0c\u7528\u4e8e\u5feb\u901f\u8bbf\u95ee\u5177\u6709\u7279\u5b9aID\u7684\u9875\u9762\u5143\u7d20\u3002\u4f7f\u7528\u6b64\u65b9\u6cd5\u53ef\u4ee5\u8282\u7701\u5f00\u53d1\u8005\u5927\u91cf\u7684\u65f6\u95f4\u548c\u52b3\u52a8\uff0c\u4f7f\u5f97\u64cd\u4f5cDOM\u5143\u7d20\u53d8\u5f97\u76f4\u63a5\u548c\u9ad8\u6548\u3002<\/p>\n<\/p>\n

\u9996\u5148\uff0c\u4f60\u9700\u8981\u4e86\u89e3getElementById<\/code>\u5982\u4f55\u5de5\u4f5c\u3002\u5f53\u4f60\u8c03\u7528\u8fd9\u4e2a\u65b9\u6cd5\u5e76\u4f20\u5165\u4e00\u4e2aID\u5b57\u7b26\u4e32\u65f6\uff0c\u6d4f\u89c8\u5668\u4f1a\u904d\u5386\u6574\u4e2aDOM\u6811\uff0c\u5bfb\u627e\u4e0e\u4e4b\u5339\u914d\u7684\u5143\u7d20\u3002\u4e00\u65e6\u627e\u5230\uff0c\u5c31\u8fd4\u56de\u8be5\u5143\u7d20\u7684\u5f15\u7528\uff1b\u5982\u679c\u6ca1\u6709\u627e\u5230\u5339\u914d\u7684\u5143\u7d20\uff0c\u5219\u8fd4\u56denull<\/code>\u3002\u7531\u4e8eID\u5728\u4e00\u4e2a\u6709\u6548\u7684HTML\u6587\u6863\u4e2d\u662f\u552f\u4e00\u7684\uff0c\u8fd9\u4e2a\u8fc7\u7a0b\u901a\u5e38\u975e\u5e38\u5feb\u901f\u3002<\/p>\n<\/p>\n

\u4f8b\u5982\uff0c\u5047\u8bbe\u4f60\u6709\u4e00\u4e2a\u5982\u4e0b\u7684HTML\u5143\u7d20\uff1a<\/p>\n<\/p>\n

<div id="uniqueId">Some Content<\/div><\/p>\n
<\/code><\/pre>\n<\/p>\n
\u4f60\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0bJavaScript\u4ee3\u7801\u83b7\u53d6\u8fd9\u4e2a\u5143\u7d20\uff1a<\/p>\n<\/p>\n
var element = document.getElementById('uniqueId');<\/p>\n
console.log(element.innerHTML); \/\/ \u8f93\u51fa: Some Content<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u8fd9\u6bb5\u4ee3\u7801\u9996\u5148\u4f7f\u7528getElementById<\/code>\u6839\u636eID\u67e5\u627e\u5143\u7d20\uff0c\u7136\u540e\u901a\u8fc7innerHTML<\/code>\u5c5e\u6027\u8f93\u51fa\u5b83\u7684\u5185\u5bb9\u3002<\/p>\n<\/p>\n
\u4e8c\u3001QUERYSELECTOR\u65b9\u6cd5<\/h3>\n<\/p>\n
\u867d\u7136getElementById<\/code>\u662f\u8bbf\u95ee\u5e26\u6709\u7279\u5b9aID\u7684\u5143\u7d20\u7684\u6700\u5feb\u65b9\u6cd5\uff0c\u4f46querySelector<\/code>\u63d0\u4f9b\u4e86\u66f4\u591a\u7684\u7075\u6d3b\u6027<\/strong>\u3002querySelector<\/code>\u53ef\u4ee5\u63a5\u53d7\u4efb\u4f55CSS\u9009\u62e9\u5668\u4f5c\u4e3a\u53c2\u6570\uff0c\u8fd9\u610f\u5473\u7740\u9664\u4e86ID\u5916\uff0c\u8fd8\u53ef\u4ee5\u6839\u636e\u7c7b\u540d\u3001\u5c5e\u6027\u6216\u4efb\u4f55\u590d\u5408\u9009\u62e9\u5668\u6765\u67e5\u627e\u5143\u7d20\u3002<\/p>\n<\/p>\n
\u4e3a\u4e86\u901a\u8fc7ID\u83b7\u53d6\u5143\u7d20\uff0c\u4f60\u9700\u8981\u5728ID\u524d\u9762\u52a0\u4e0a#<\/code>\u5b57\u7b26\uff0c\u8fd9\u8868\u793aID\u9009\u62e9\u5668\u3002\u4f7f\u7528querySelector<\/code>\u65f6\uff0c\u5982\u679c\u6709\u591a\u4e2a\u5339\u914d\u7684\u5143\u7d20\uff0c\u5b83\u53ea\u4f1a\u8fd4\u56de\u7b2c\u4e00\u4e2a\u5339\u914d\u5143\u7d20\u3002<\/p>\n<\/p>\n
\u4f8b\u5982\uff0c\u4f7f\u7528\u76f8\u540c\u7684HTML\u5143\u7d20\uff1a<\/p>\n<\/p>\n
<div id="uniqueId">Another Content<\/div><\/p>\n
<\/code><\/pre>\n<\/p>\n
\u4f60\u53ef\u4ee5\u901a\u8fc7\u4ee5\u4e0bJavaScript\u4ee3\u7801\u6765\u83b7\u53d6\u5b83\uff1a<\/p>\n<\/p>\n
var element = document.querySelector('#uniqueId');<\/p>\n
console.log(element.innerHTML); \/\/ \u8f93\u51fa: Another Content<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u8fd9\u8bc1\u660e\u4e86querySelector<\/code>\u867d\u7136\u6bd4getElementById<\/code>\u7a0d\u6162\uff0c\u4f46\u5728\u9700\u8981\u4f7f\u7528\u66f4\u590d\u6742\u9009\u62e9\u5668\u7684\u60c5\u51b5\u4e0b\u975e\u5e38\u6709\u7528\u3002<\/p>\n<\/p>\n
\u4e09\u3001\u6027\u80fd\u8003\u91cf<\/h3>\n<\/p>\n
\u5f53\u6d89\u53ca\u5230\u5927\u91cf\u7684DOM\u64cd\u4f5c\u65f6\uff0c\u6027\u80fd\u6210\u4e3a\u4e86\u4e00\u4e2a\u4e0d\u53ef\u5ffd\u89c6\u7684\u8003\u8651\u56e0\u7d20\u3002getElementById<\/code>\u5728\u6027\u80fd\u4e0a\u901a\u5e38\u4f18\u4e8equerySelector<\/code><\/strong>\uff0c\u56e0\u4e3a\u5b83\u4e13\u95e8\u7528\u4e8e\u901a\u8fc7ID\u6765\u67e5\u627e\u5143\u7d20\uff0c\u800c\u6d4f\u89c8\u5668\u5bf9\u8fd9\u4e00\u64cd\u4f5c\u505a\u4e86\u4f18\u5316\u3002\u7136\u800c\uff0c\u5728\u73b0\u4ee3\u7684Web\u5e94\u7528\u4e2d\uff0c\u4e24\u8005\u4e4b\u95f4\u7684\u6027\u80fd\u5dee\u5f02\u901a\u5e38\u662f\u5fae\u4e0d\u8db3\u9053\u7684\uff0c\u7279\u522b\u662f\u5728\u5904\u7406\u5c11\u91cfDOM\u5143\u7d20\u65f6\u3002<\/p>\n<\/p>\n
\u4f46\u662f\uff0c\u5982\u679c\u4f60\u6b63\u5728\u5f00\u53d1\u4e00\u4e2a\u9ad8\u6027\u80fd\u7684\u5e94\u7528\uff0c\u5e76\u9700\u8981\u9891\u7e41\u5730\u64cd\u4f5cDOM\uff0c\u90a3\u4e48\u4f18\u5148\u9009\u62e9getElementById<\/code>\u4f1a\u662f\u4e00\u4e2a\u66f4\u597d\u7684\u9009\u62e9\u3002<\/p>\n<\/p>\n
\u56db\u3001\u6700\u4f73\u5b9e\u8df5<\/h3>\n<\/p>\n
\u5c3d\u7ba1getElementById<\/code>\u548cquerySelector<\/code>\u90fd\u662f\u83b7\u53d6ID\u5c5e\u6027\u7684\u6709\u6548\u65b9\u6cd5\uff0c\u4f46\u5b83\u4eec\u5404\u6709\u4f18\u52bf\u3002\u9009\u62e9\u54ea\u4e00\u79cd\u65b9\u5f0f\u53d6\u51b3\u4e8e\u4f60\u7684\u5177\u4f53\u9700\u6c42\u548c\u9879\u76ee\u7684\u6027\u8d28\u3002<\/p>\n<\/p>\n
    \n
  • \u5f53\u786e\u5207\u77e5\u9053\u8981\u67e5\u8be2\u7684\u5143\u7d20ID\uff0c\u5e76\u4e14\u5bf9\u6027\u80fd\u6709\u6781\u81f4\u8ffd\u6c42\u65f6\uff0c\u5e94\u4f18\u5148\u8003\u8651\u4f7f\u7528getElementById<\/code>\u3002<\/strong><\/li>\n
  • \u5f53\u9700\u8981\u4f7f\u7528\u66f4\u901a\u7528\u7684CSS\u9009\u62e9\u5668\uff0c\u6216\u662f\u5728\u76f8\u540c\u7684\u4ee3\u7801\u5757\u4e2d\u9700\u8981\u67e5\u8be2\u591a\u79cd\u7c7b\u578b\u7684\u5143\u7d20\u65f6\uff0cquerySelector<\/code>\u662f\u66f4\u7075\u6d3b\u7684\u9009\u62e9\u3002<\/strong><\/li>\n<\/ul>\n
    \u603b\u7684\u6765\u8bf4\uff0c\u638c\u63e1\u8fd9\u4e24\u79cd\u65b9\u6cd5\uff0c\u610f\u5473\u7740\u4f60\u53ef\u4ee5\u6839\u636e\u5b9e\u9645\u9700\u6c42\u9ad8\u6548\u5730\u8bbf\u95ee\u548c\u64cd\u4f5cDOM\u5143\u7d20\uff0c\u4f7f\u4f60\u7684JavaScript\u4ee3\u7801\u66f4\u52a0\u7b80\u6d01\u548c\u5f3a\u5927\u3002<\/p>\n<\/p>\n
    \u76f8\u5173\u95ee\u7b54FAQs\uff1a<\/strong><\/h2>\n
    1. JavaScript\u4e2d\u5982\u4f55\u83b7\u53d6HTML\u5143\u7d20\u7684id\u5c5e\u6027\uff1f<\/strong><\/p>\n
    \u5728JavaScript\u4e2d\uff0c\u8981\u83b7\u53d6HTML\u5143\u7d20\u7684id\u5c5e\u6027\uff0c\u53ef\u4ee5\u4f7f\u7528getElementById<\/code>\u51fd\u6570\u3002\u4f8b\u5982\uff0c\u5982\u679c\u8981\u83b7\u53d6id\u4e3a"myElement"\u7684\u5143\u7d20\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u4ee3\u7801\uff1a<\/p>\n
    var element = document.getElementById("myElement");\n<\/code><\/pre>\n
    \u8fd9\u5c06\u8fd4\u56de\u5177\u6709\u6307\u5b9aid\u7684\u5143\u7d20\u5bf9\u8c61\uff0c\u5e76\u5c06\u5176\u8d4b\u503c\u7ed9\u53d8\u91cf"element"\u3002\u60a8\u53ef\u4ee5\u8fdb\u4e00\u6b65\u901a\u8fc7\u53d8\u91cf"element"\u6765\u64cd\u4f5c\u8be5\u5143\u7d20\uff0c\u4f8b\u5982\u4fee\u6539\u5176\u5185\u5bb9\u3001\u6837\u5f0f\u6216\u6dfb\u52a0\u4e8b\u4ef6\u76d1\u542c\u5668\u3002<\/p>\n
    2. \u5982\u4f55\u68c0\u67e5\u5143\u7d20\u662f\u5426\u5177\u6709id\u5c5e\u6027\u5e76\u83b7\u53d6\u5176\u503c\uff1f<\/strong><\/p>\n
    \u5982\u679c\u8981\u68c0\u67e5\u4e00\u4e2a\u5143\u7d20\u662f\u5426\u5177\u6709id\u5c5e\u6027\u5e76\u83b7\u53d6\u5176\u503c\uff0c\u53ef\u4ee5\u4f7f\u7528JavaScript\u4e2d\u7684hasAttribute<\/code>\u548cgetAttribute<\/code>\u65b9\u6cd5\u3002\u4ee5\u4e0b\u662f\u4e00\u4e2a\u4f8b\u5b50\uff1a<\/p>\n
    var element = document.getElementById("myElement");\n\nif (element.hasAttribute("id")) {\n  var idValue = element.getAttribute("id");\n  console.log("\u5143\u7d20\u5177\u6709id\u5c5e\u6027\uff0c\u503c\u4e3a\uff1a" + idValue);\n} else {\n  console.log("\u5143\u7d20\u6ca1\u6709id\u5c5e\u6027");\n}\n<\/code><\/pre>\n
    \u8fd9\u5c06\u5728\u63a7\u5236\u53f0\u8f93\u51fa\u5143\u7d20\u662f\u5426\u5177\u6709id\u5c5e\u6027\uff0c\u5e76\u663e\u793a\u5b83\u7684\u503c\uff08\u5982\u679c\u5b58\u5728\uff09\u3002<\/p>\n
    3. \u5982\u4f55\u4f7f\u7528JavaScript\u83b7\u53d6\u5177\u6709\u7279\u5b9aid\u5c5e\u6027\u503c\u7684\u6240\u6709\u5143\u7d20\uff1f<\/strong><\/p>\n
    \u5982\u679c\u60f3\u8981\u83b7\u53d6\u5177\u6709\u7279\u5b9aid\u5c5e\u6027\u503c\u7684\u6240\u6709\u5143\u7d20\uff0c\u53ef\u4ee5\u4f7f\u7528querySelectorAll<\/code>\u65b9\u6cd5\u3002\u4ee5\u4e0b\u662f\u4e00\u4e2a\u4f8b\u5b50\uff1a<\/p>\n
    var elements = document.querySelectorAll("[id='myId']");\n\nfor (var i = 0; i < elements.length; i++) {\n  console.log(elements[i]);\n}\n<\/code><\/pre>\n
    \u8fd9\u5c06\u8fd4\u56de\u9009\u5b9a\u6587\u6863\u4e2d\u5177\u6709\u6307\u5b9aid\u5c5e\u6027\u503c\uff08\u4f8b\u5982"myId"\uff09\u7684\u6240\u6709\u5143\u7d20\uff0c\u5e76\u5c06\u5b83\u4eec\u5b58\u50a8\u5728\u4e00\u4e2a\u7c7b\u6570\u7ec4\u5bf9\u8c61\u4e2d\u3002\u7136\u540e\uff0c\u60a8\u53ef\u4ee5\u904d\u5386\u8be5\u5bf9\u8c61\uff0c\u5bf9\u6bcf\u4e2a\u5339\u914d\u7684\u5143\u7d20\u6267\u884c\u9700\u8981\u7684\u64cd\u4f5c\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"\u83b7\u53d6\u5143\u7d20\u7684ID\u5c5e\u6027\u5728JavaScript\u5f00\u53d1\u4e2d\u662f\u4e00\u9879\u57fa\u672c\u800c\u91cd\u8981\u7684\u6280\u80fd\u3002\u4e3b\u8981\u7684\u65b9\u6cd5\u6709getElementById […]","protected":false},"author":3,"featured_media":168481,"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\/168462"}],"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=168462"}],"version-history":[{"count":0,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts\/168462\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/media\/168481"}],"wp:attachment":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/media?parent=168462"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/categories?post=168462"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/tags?post=168462"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}