{"id":1485,"date":"2024-11-10T11:51:48","date_gmt":"2024-11-10T03:51:48","guid":{"rendered":"https:\/\/fwq.ai\/blog\/1485\/"},"modified":"2024-11-10T11:51:48","modified_gmt":"2024-11-10T03:51:48","slug":"javascript%e4%b8%ad%e5%a6%82%e4%bd%95%e8%8e%b7%e5%8f%96%e5%8c%85%e5%90%ab%e7%a9%ba%e5%85%83%e7%b4%a0%e7%9a%84%e6%95%b0%e7%bb%84%e7%9a%84%e7%a9%ba%e5%85%83%e7%b4%a0%e4%b8%aa%e6%95%b0%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/fwq.ai\/blog\/1485\/","title":{"rendered":"JavaScript\u4e2d\u5982\u4f55\u83b7\u53d6\u5305\u542b\u7a7a\u5143\u7d20\u7684\u6570\u7ec4\u7684\u7a7a\u5143\u7d20\u4e2a\u6570\uff1f"},"content":{"rendered":"<p><img decoding=\"async\" src=\"https:\/\/img.php.cn\/upload\/article\/001\/246\/273\/173044667266535.jpg\" class=\"aligncenter\" title=\"JavaScript\u4e2d\u5982\u4f55\u83b7\u53d6\u5305\u542b\u7a7a\u5143\u7d20\u7684\u6570\u7ec4\u7684\u7a7a\u5143\u7d20\u4e2a\u6570\uff1f\u63d2\u56fe\" alt=\"JavaScript\u4e2d\u5982\u4f55\u83b7\u53d6\u5305\u542b\u7a7a\u5143\u7d20\u7684\u6570\u7ec4\u7684\u7a7a\u5143\u7d20\u4e2a\u6570\uff1f\u63d2\u56fe\" \/><\/p>\n<p><strong>\u5982\u4f55\u83b7\u53d6\u7a7a\u5143\u7d20\u7684\u957f\u5ea6\uff1f<\/strong><\/p>\n<p>\u5728javascript\u4e2d\uff0c\u83b7\u53d6\u5305\u542b\u7a7a\u5143\u7d20\u7684\u6570\u7ec4\u7684\u957f\u5ea6\u901a\u5e38\u662f\u4e00\u4e2a\u68d8\u624b\u7684\u4efb\u52a1\u3002\u7136\u800c\uff0c\u901a\u8fc7\u4f7f\u7528\u9ad8\u9636\u51fd\u6570filter\uff0c\u6211\u4eec\u53ef\u4ee5\u8f7b\u677e\u5b9e\u73b0\u8fd9\u4e00\u76ee\u6807\u3002<\/p>\n<pre>[1, 2, null, null, 5]\n  .filter(function(item) {\n    return item === null;\n  })\n  .length;<\/pre>\n<p>  \u767b\u5f55\u540e\u590d\u5236   <\/p>\n<p>\u8fd9\u6bb5\u4ee3\u7801\u5c06\u4f7f\u7528filter\u51fd\u6570\u904d\u5386\u6570\u7ec4\uff0c\u627e\u51fa\u6240\u6709\u503c\u4e3anull\u7684\u5143\u7d20\uff0c\u5e76\u8fd4\u56de\u4e00\u4e2a\u5305\u542b\u8fd9\u4e9b\u5143\u7d20\u7684\u65b0\u6570\u7ec4\u3002\u7136\u540e\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528length\u5c5e\u6027\u6765\u83b7\u53d6\u8be5\u6570\u7ec4\u7684\u957f\u5ea6\uff0c\u4ece\u800c\u5f97\u5230\u7a7a\u5143\u7d20\u7684\u4e2a\u6570\u3002<\/p>\n<p>\u4ee5\u4e0a\u5c31\u662fJavaScript\u4e2d\u5982\u4f55\u83b7\u53d6\u5305\u542b\u7a7a\u5143\u7d20\u7684\u6570\u7ec4\u7684\u7a7a\u5143\u7d20\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":"<p>\u5982\u4f55\u83b7\u53d6\u7a7a\u5143\u7d20\u7684\u957f\u5ea6\uff1f \u5728javascript\u4e2d\uff0c\u83b7\u53d6\u5305\u542b\u7a7a\u5143\u7d20\u7684\u6570\u7ec4\u7684\u957f\u5ea6\u901a\u5e38\u662f\u4e00\u4e2a\u68d8\u624b\u7684\u4efb\u52a1\u3002\u7136\u800c\uff0c\u901a\u8fc7\u4f7f\u7528\u9ad8\u9636\u51fd\u6570filter\uff0c\u6211\u4eec\u53ef\u4ee5\u8f7b\u677e\u5b9e\u73b0\u8fd9\u4e00\u76ee\u6807\u3002 [1, 2, null, null, 5] .filter(function(item) { return item === null; }) .length; \u767b\u5f55\u540e\u590d\u5236 \u8fd9\u6bb5\u4ee3\u7801\u5c06\u4f7f\u7528filter\u51fd\u6570\u904d\u5386\u6570\u7ec4\uff0c\u627e\u51fa\u6240\u6709\u503c\u4e3anull\u7684\u5143\u7d20\uff0c\u5e76\u8fd4\u56de\u4e00\u4e2a\u5305\u542b\u8fd9\u4e9b\u5143\u7d20\u7684\u65b0\u6570\u7ec4\u3002\u7136\u540e\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528length\u5c5e\u6027\u6765\u83b7\u53d6\u8be5\u6570\u7ec4\u7684\u957f\u5ea6\uff0c\u4ece\u800c\u5f97\u5230\u7a7a\u5143\u7d20\u7684\u4e2a\u6570\u3002 \u4ee5\u4e0a\u5c31\u662fJavaScript\u4e2d\u5982\u4f55\u83b7\u53d6\u5305\u542b\u7a7a\u5143\u7d20\u7684\u6570\u7ec4\u7684\u7a7a\u5143\u7d20\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-1485","post","type-post","status-publish","format-standard","hentry","category-16"],"_links":{"self":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/1485","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=1485"}],"version-history":[{"count":0,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/1485\/revisions"}],"wp:attachment":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/media?parent=1485"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/categories?post=1485"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/tags?post=1485"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}