{"id":4011,"date":"2024-11-10T11:51:40","date_gmt":"2024-11-10T03:51:40","guid":{"rendered":"https:\/\/fwq.ai\/blog\/4011\/"},"modified":"2024-11-10T11:51:40","modified_gmt":"2024-11-10T03:51:40","slug":"javascript%e4%b8%ad%e7%9a%84void-0%e7%a9%b6%e7%ab%9f%e4%bb%a3%e8%a1%a8%e4%bb%80%e4%b9%88%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/fwq.ai\/blog\/4011\/","title":{"rendered":"JavaScript\u4e2d\u7684&#8221;void 0&#8243;\u7a76\u7adf\u4ee3\u8868\u4ec0\u4e48\uff1f"},"content":{"rendered":"<p><img decoding=\"async\" src=\"https:\/\/img.php.cn\/upload\/article\/001\/246\/273\/173121141118441.jpg\" class=\"aligncenter\" title=\"JavaScript\u4e2d\u7684&#8221;void 0&#8243;\u7a76\u7adf\u4ee3\u8868\u4ec0\u4e48\uff1f\u63d2\u56fe\" alt=\"JavaScript\u4e2d\u7684&#8221;void 0&#8243;\u7a76\u7adf\u4ee3\u8868\u4ec0\u4e48\uff1f\u63d2\u56fe\" \/><\/p>\n<p><strong>void 0 \u5728 JavaScript \u4e2d\u7684\u542b\u4e49<\/strong><\/p>\n<p>\u5728 JavaScript \u4e2d\uff0c&#8221;void 0&#8243; \u8868\u793a\u672a\u5b9a\u4e49\u503c\uff08undefined\uff09\u3002undefined \u662f\u6570\u636e\u7c7b\u578b\u4e2d\u7684\u4e00\u79cd\u7279\u6b8a\u503c\uff0c\u8868\u793a\u53d8\u91cf\u672a\u88ab\u521d\u59cb\u5316\u6216\u5c1a\u672a\u8d4b\u503c\u3002<\/p>\n<p><strong>\u793a\u4f8b\u5206\u6790<\/strong><\/p>\n<p>\u4f60\u63d0\u4f9b\u7684\u4ee3\u7801\u6bb5\u4e2d\u6709\u4e00\u884c\u4ee3\u7801\uff1a&#8221;void 0 !== r&#8221;\u3002\u8fd9\u884c\u4ee3\u7801\u7684\u610f\u601d\u662f\u68c0\u67e5 r \u662f\u5426\u4e0d\u7b49\u4e8e undefined\u3002<\/p>\n<p><span>\u7acb\u5373\u5b66\u4e60<\/span>\u201c\u201d\uff1b<\/p>\n<ul>\n<li>\u5982\u679c r \u88ab\u5b9a\u4e49\u4e14\u4e0d\u7b49\u4e8e undefined\uff0c\u5219\u8fd4\u56de true\u3002<\/li>\n<li>\u5982\u679c r \u672a\u5b9a\u4e49\u6216\u7b49\u4e8e undefined\uff0c\u5219\u8fd4\u56de false\u3002<\/li>\n<\/ul>\n<p><strong>\u4f5c\u7528<\/strong><\/p>\n<p>\u5728 JavaScript \u4e2d\u4f7f\u7528 &#8220;void 0&#8221; \u7684\u539f\u56e0\u4e3b\u8981\u6709\u4ee5\u4e0b\u51e0\u4e2a\uff1a<\/p>\n<ul>\n<li> <strong>\u5f3a\u5236\u8f6c\u6362 undefined\uff1a<\/strong>\u5f53\u9700\u8981\u5c06 undefined \u5f3a\u5236\u8f6c\u6362\u4e3a\u5e03\u5c14\u503c\u65f6\uff0c\u53ef\u4ee5\u4f7f\u7528 &#8220;void 0&#8243;\u3002\u4f8b\u5982\uff0c\u4ee5\u4e0b\u4ee3\u7801\u5c06 undefined \u8f6c\u6362\u4e3a false\uff1a&#8221;Boolean(void 0)&#8221; == false\u3002<\/li>\n<li> <strong>\u89e3\u51b3 &#8220;undefined is not a function&#8221; \u9519\u8bef\uff1a<\/strong>\u6709\u65f6\uff0c\u5728\u4ee3\u7801\u4e2d\u4f7f\u7528\u672a\u5b9a\u4e49\u7684\u53d8\u91cf\u53ef\u80fd\u4f1a\u5bfc\u81f4 &#8220;undefined is not a function&#8221; \u9519\u8bef\u3002\u4e3a\u4e86\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\uff0c\u53ef\u4ee5\u5728\u53d8\u91cf\u524d\u9762\u52a0\u4e0a &#8220;void 0&#8243;\uff0c\u4ee5\u5f3a\u5236\u5c06\u5176\u8f6c\u6362\u4e3a undefined\u3002<\/li>\n<li> <strong>\u8868\u793a\u4e0d\u5b58\u5728\uff1a<\/strong>&#8220;void 0&#8221; \u8fd8\u53ef\u4ee5\u7528\u4e8e\u8868\u793a\u67d0\u4e2a\u503c\u4e0d\u5b58\u5728\u6216\u4e0d\u9002\u7528\u3002\u4f8b\u5982\uff0c\u4ee5\u4e0b\u4ee3\u7801\u4f7f\u7528 &#8220;void 0&#8221; \u8868\u793a\u4e00\u4e2a\u51fd\u6570\u6ca1\u6709\u8fd4\u56de\u4efb\u4f55\u4e1c\u897f\uff1a&#8221;function() { return void 0; }&#8221;\u3002<\/li>\n<\/ul>\n<p>\u4ee5\u4e0a\u5c31\u662fJavaScript\u4e2d\u7684&#8221;void 0&#8243;\u7a76\u7adf\u4ee3\u8868\u4ec0\u4e48\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>void 0 \u5728 JavaScript \u4e2d\u7684\u542b\u4e49 \u5728 JavaScript \u4e2d\uff0c&#8221;void 0&#8243; \u8868\u793a\u672a\u5b9a\u4e49\u503c\uff08undefined\uff09\u3002undefined \u662f\u6570\u636e\u7c7b\u578b\u4e2d\u7684\u4e00\u79cd\u7279\u6b8a\u503c\uff0c\u8868\u793a\u53d8\u91cf\u672a\u88ab\u521d\u59cb\u5316\u6216\u5c1a\u672a\u8d4b\u503c\u3002 \u793a\u4f8b\u5206\u6790 \u4f60\u63d0\u4f9b\u7684\u4ee3\u7801\u6bb5\u4e2d\u6709\u4e00\u884c\u4ee3\u7801\uff1a&#8221;void 0 !== r&#8221;\u3002\u8fd9\u884c\u4ee3\u7801\u7684\u610f\u601d\u662f\u68c0\u67e5 r \u662f\u5426\u4e0d\u7b49\u4e8e undefined\u3002 \u7acb\u5373\u5b66\u4e60\u201c\u201d\uff1b \u5982\u679c r \u88ab\u5b9a\u4e49\u4e14\u4e0d\u7b49\u4e8e undefined\uff0c\u5219\u8fd4\u56de true\u3002 \u5982\u679c r \u672a\u5b9a\u4e49\u6216\u7b49\u4e8e undefined\uff0c\u5219\u8fd4\u56de false\u3002 \u4f5c\u7528 \u5728 JavaScript \u4e2d\u4f7f\u7528 &#8220;void 0&#8221; \u7684\u539f\u56e0\u4e3b\u8981\u6709\u4ee5\u4e0b\u51e0\u4e2a\uff1a \u5f3a\u5236\u8f6c\u6362 undefined\uff1a\u5f53\u9700\u8981\u5c06 undefined \u5f3a\u5236\u8f6c\u6362\u4e3a\u5e03\u5c14\u503c\u65f6\uff0c\u53ef\u4ee5\u4f7f\u7528 &#8220;void 0&#8243;\u3002\u4f8b\u5982\uff0c\u4ee5\u4e0b\u4ee3\u7801\u5c06 undefined \u8f6c\u6362\u4e3a false\uff1a&#8221;Boolean(void 0)&#8221; == false\u3002 \u89e3\u51b3 &#8220;undefined is not a function&#8221; [&hellip;]<\/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-4011","post","type-post","status-publish","format-standard","hentry","category-16"],"_links":{"self":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/4011","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=4011"}],"version-history":[{"count":0,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/4011\/revisions"}],"wp:attachment":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/media?parent=4011"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/categories?post=4011"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/tags?post=4011"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}