{"id":1417,"date":"2024-11-10T10:43:23","date_gmt":"2024-11-10T02:43:23","guid":{"rendered":"https:\/\/fwq.ai\/blog\/1417\/"},"modified":"2024-11-10T10:43:23","modified_gmt":"2024-11-10T02:43:23","slug":"%e5%a6%82%e4%bd%95%e4%bd%bf%e7%94%a8-javascript-%e8%8e%b7%e5%8f%96%e6%95%b0%e7%bb%84%e4%b8%ad%e7%a9%ba%e5%86%85%e5%ae%b9%e5%85%83%e7%b4%a0%e7%9a%84%e4%b8%aa%e6%95%b0%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/fwq.ai\/blog\/1417\/","title":{"rendered":"\u5982\u4f55\u4f7f\u7528 JavaScript \u83b7\u53d6\u6570\u7ec4\u4e2d\u7a7a\u5185\u5bb9\u5143\u7d20\u7684\u4e2a\u6570\uff1f"},"content":{"rendered":"

\"\u5982\u4f55\u4f7f\u7528<\/p>\n

javascript \u83b7\u53d6\u7a7a\u5185\u5bb9\u5143\u7d20\u7684\u957f\u5ea6<\/strong><\/p>\n

\u60f3\u8981\u83b7\u53d6\u7a7a\u5185\u5bb9\u5143\u7d20\u7684\u957f\u5ea6\uff0c\u53ef\u4ee5\u4f7f\u7528 javascript \u7684\u9ad8\u9636\u51fd\u6570 filter\u3002<\/p>\n

filter \u51fd\u6570\u53ef\u4ee5\u6839\u636e\u63d0\u4f9b\u7684\u6761\u4ef6\u7b5b\u9009\u6570\u7ec4\u4e2d\u7b26\u5408\u6761\u4ef6\u7684\u5143\u7d20\uff0c\u5e76\u8fd4\u56de\u4e00\u4e2a\u65b0\u7684\u6570\u7ec4\uff0c\u5176\u4e2d\u5305\u542b\u7b26\u5408\u6761\u4ef6\u7684\u5143\u7d20\u3002\u5bf9\u4e8e\u7a7a\u5185\u5bb9\u5143\u7d20\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u6761\u4ef6\u8fdb\u884c\u7b5b\u9009\uff1a<\/p>\n

function(element) {\n  return element === null;\n}<\/pre>\n
 \u767b\u5f55\u540e\u590d\u5236 <\/p>\n
\u6b64\u6761\u4ef6\u68c0\u67e5\u5143\u7d20\u662f\u5426\u4e3a null\uff0c\u5982\u679c\u662f\uff0c\u5219\u8fd4\u56de true\uff0c\u5426\u5219\u8fd4\u56de false\u3002<\/p>\n
\u7acb\u5373\u5b66\u4e60<\/span>\u201c\u201d\uff1b<\/p>\n
\u4f7f\u7528\u6b64\u6761\u4ef6\u5bf9\u6570\u7ec4\u8fdb\u884c\u7b5b\u9009\uff0c\u5e76\u5c06\u7b5b\u9009\u7ed3\u679c\u7684\u957f\u5ea6\u4f5c\u4e3a\u60f3\u8981\u7684\u957f\u5ea6\uff1a<\/p>\n
let length = [1, 2, null, null, 5].filter(function(element) {\n  return element === null;\n}).length;<\/pre>\n
 \u767b\u5f55\u540e\u590d\u5236 <\/p>\n
\u8fd9\u6837\uff0clength \u5373\u4e3a\u6570\u7ec4\u4e2d\u7a7a\u5185\u5bb9\u5143\u7d20\u7684\u4e2a\u6570\u3002<\/p>\n
\u4ee5\u4e0a\u5c31\u662f\u5982\u4f55\u4f7f\u7528 JavaScript \u83b7\u53d6\u6570\u7ec4\u4e2d\u7a7a\u5185\u5bb9\u5143\u7d20\u7684\u4e2a\u6570\uff1f\u7684\u8be6\u7ec6\u5185\u5bb9\uff0c\u66f4\u591a\u8bf7\u5173\u6ce8\u7c73\u4e91\u5176\u5b83\u76f8\u5173\u6587\u7ae0\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"
javascript \u83b7\u53d6\u7a7a\u5185\u5bb9\u5143\u7d20\u7684\u957f\u5ea6 \u60f3\u8981\u83b7\u53d6\u7a7a\u5185\u5bb9\u5143\u7d20\u7684\u957f\u5ea6\uff0c\u53ef\u4ee5\u4f7f\u7528 javascript \u7684\u9ad8\u9636\u51fd\u6570 filter\u3002 filter \u51fd\u6570\u53ef\u4ee5\u6839\u636e\u63d0\u4f9b\u7684\u6761\u4ef6\u7b5b\u9009\u6570\u7ec4\u4e2d\u7b26\u5408\u6761\u4ef6\u7684\u5143\u7d20\uff0c\u5e76\u8fd4\u56de\u4e00\u4e2a\u65b0\u7684\u6570\u7ec4\uff0c\u5176\u4e2d\u5305\u542b\u7b26\u5408\u6761\u4ef6\u7684\u5143\u7d20\u3002\u5bf9\u4e8e\u7a7a\u5185\u5bb9\u5143\u7d20\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u6761\u4ef6\u8fdb\u884c\u7b5b\u9009\uff1a function(element) { return element === null; } \u767b\u5f55\u540e\u590d\u5236 \u6b64\u6761\u4ef6\u68c0\u67e5\u5143\u7d20\u662f\u5426\u4e3a null\uff0c\u5982\u679c\u662f\uff0c\u5219\u8fd4\u56de true\uff0c\u5426\u5219\u8fd4\u56de false\u3002 \u7acb\u5373\u5b66\u4e60\u201c\u201d\uff1b \u4f7f\u7528\u6b64\u6761\u4ef6\u5bf9\u6570\u7ec4\u8fdb\u884c\u7b5b\u9009\uff0c\u5e76\u5c06\u7b5b\u9009\u7ed3\u679c\u7684\u957f\u5ea6\u4f5c\u4e3a\u60f3\u8981\u7684\u957f\u5ea6\uff1a let length = [1, 2, null, null, 5].filter(function(element) { return element === null; }).length; \u767b\u5f55\u540e\u590d\u5236 \u8fd9\u6837\uff0clength \u5373\u4e3a\u6570\u7ec4\u4e2d\u7a7a\u5185\u5bb9\u5143\u7d20\u7684\u4e2a\u6570\u3002 \u4ee5\u4e0a\u5c31\u662f\u5982\u4f55\u4f7f\u7528 JavaScript \u83b7\u53d6\u6570\u7ec4\u4e2d\u7a7a\u5185\u5bb9\u5143\u7d20\u7684\u4e2a\u6570\uff1f\u7684\u8be6\u7ec6\u5185\u5bb9\uff0c\u66f4\u591a\u8bf7\u5173\u6ce8\u7c73\u4e91\u5176\u5b83\u76f8\u5173\u6587\u7ae0\uff01<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[16],"tags":[],"class_list":["post-1417","post","type-post","status-publish","format-standard","hentry","category-16"],"_links":{"self":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/1417","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/comments?post=1417"}],"version-history":[{"count":0,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/1417\/revisions"}],"wp:attachment":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/media?parent=1417"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/categories?post=1417"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/tags?post=1417"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}