{"id":2538,"date":"2024-11-10T14:39:32","date_gmt":"2024-11-10T06:39:32","guid":{"rendered":"https:\/\/fwq.ai\/blog\/2538\/"},"modified":"2024-11-10T14:39:32","modified_gmt":"2024-11-10T06:39:32","slug":"javascript-%e4%b8%ad%e7%9a%84-this-%e6%8c%87%e5%90%91%e8%b0%81%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/fwq.ai\/blog\/2538\/","title":{"rendered":"JavaScript \u4e2d\u7684 `this` \u6307\u5411\u8c01\uff1f"},"content":{"rendered":"<p><img decoding=\"async\" src=\"https:\/\/img.php.cn\/upload\/article\/001\/246\/273\/173078699138916.jpg\" class=\"aligncenter\" title=\"JavaScript \u4e2d\u7684 `this` \u6307\u5411\u8c01\uff1f\u63d2\u56fe\" alt=\"JavaScript \u4e2d\u7684 `this` \u6307\u5411\u8c01\uff1f\u63d2\u56fe\" \/><\/p>\n<p><strong>js\u4e2dthis\u7684\u7528\u6cd5<\/strong><\/p>\n<p>\u5982\u4e0a\u6240\u8ff0\uff0cthis\u7684\u503c\u6839\u636e\u51fd\u6570\u7684\u8c03\u7528\u65b9\u5f0f\u800c\u53d8\u5316\uff0c\u4f46\u59cb\u7ec8\u8868\u793a\u8c03\u7528\u51fd\u6570\u7684\u5bf9\u8c61\u3002\u90a3\u4e48\uff0c\u5982\u4f55\u786e\u5b9a\u51fd\u6570\u5bf9\u5e94\u7684\u5bf9\u8c61\u5462\uff1f\u4ee5\u4e0b\u662f\u4e00\u4e9b\u5e38\u89c1\u7684\u89c4\u5219\uff1a<\/p>\n<ul>\n<li> <strong>\u65b9\u6cd5\u8c03\u7528\uff1a<\/strong>\u5f53\u51fd\u6570\u4f5c\u4e3a\u5bf9\u8c61\u65b9\u6cd5\u8c03\u7528\u65f6\uff0cthis\u8868\u793a\u8be5\u5bf9\u8c61\u3002\u4f8b\u5982\uff1a<\/li>\n<\/ul>\n<pre>const obj = {\n  name: \"john\",\n  greet() {\n    console.log(`hello, ${this.name}!`);\n  }\n};\n\nobj.greet(); \/\/ \u8f93\u51fa \"hello, john!\"<\/pre>\n<p>  \u767b\u5f55\u540e\u590d\u5236   <\/p>\n<ul>\n<li> <strong>\u666e\u901a\u51fd\u6570\u8c03\u7528\uff1a<\/strong>\u5f53\u51fd\u6570\u4f5c\u4e3a\u666e\u901a\u51fd\u6570\u8c03\u7528\u65f6\uff0cthis\u6307\u5411\u5168\u5c40\u5bf9\u8c61\uff08\u6d4f\u89c8\u5668\u4e2d\u4e3a&#8221;window&#8221;\uff0cnode.js\u4e2d\u4e3a&#8221;global&#8221;\uff09\u3002\u4f8b\u5982\uff1a<\/li>\n<\/ul>\n<pre>function greet() {\n  console.log(`hello, ${this.name}!`);\n}\n\ngreet(); \/\/ \u8f93\u51fa\u62a5\u9519\uff1athis.name is undefined<\/pre>\n<p>  \u767b\u5f55\u540e\u590d\u5236   <\/p>\n<ul>\n<li> <strong>\u6784\u9020\u51fd\u6570\u8c03\u7528\uff1a<\/strong>\u5f53\u51fd\u6570\u4f5c\u4e3a\u6784\u9020\u51fd\u6570\u8c03\u7528\u65f6\uff0cthis\u6307\u5411\u65b0\u521b\u5efa\u7684\u5bf9\u8c61\u3002\u4f8b\u5982\uff1a<\/li>\n<\/ul>\n<pre>function person(name) {\n  this.name = name;\n}\n\nconst person = new person(\"jane\");\n\nconsole.log(person.name); \/\/ \u8f93\u51fa \"jane\"<\/pre>\n<p>  \u767b\u5f55\u540e\u590d\u5236   <\/p>\n<ul>\n<li> <strong>\u95f4\u63a5\u8c03\u7528\uff1a<\/strong>\u5f53\u51fd\u6570\u901a\u8fc7\u4ee3\u7406\u5bf9\u8c61\uff08\u5982&#8221;call&#8221;\u3001&#8221;apply&#8221;\u6216&#8221;bind&#8221;\u65b9\u6cd5\uff09\u8c03\u7528\u65f6\uff0cthis\u53ef\u4ee5\u624b\u52a8\u8bbe\u7f6e\u3002\u4f8b\u5982\uff1a<\/li>\n<\/ul>\n<pre>const person = {\n  name: \"John\"\n};\n\nfunction greet() {\n  console.log(`Hello, ${this.name}!`);\n}\n\ngreet.call(person); \/\/ \u8f93\u51fa \"Hello, John!\"<\/pre>\n<p>  \u767b\u5f55\u540e\u590d\u5236   <\/p>\n<p>\u7406\u89e3this\u7684\u7528\u6cd5\u81f3\u5173\u91cd\u8981\uff0c\u56e0\u4e3a\u5b83\u51b3\u5b9a\u4e86\u51fd\u6570\u5185\u90e8\u5bf9\u5bf9\u8c61\u5c5e\u6027\u548c\u65b9\u6cd5\u7684\u8bbf\u95ee\u65b9\u5f0f\u3002<\/p>\n<p>\u4ee5\u4e0a\u5c31\u662fJavaScript \u4e2d\u7684 `this` \u6307\u5411\u8c01\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>js\u4e2dthis\u7684\u7528\u6cd5 \u5982\u4e0a\u6240\u8ff0\uff0cthis\u7684\u503c\u6839\u636e\u51fd\u6570\u7684\u8c03\u7528\u65b9\u5f0f\u800c\u53d8\u5316\uff0c\u4f46\u59cb\u7ec8\u8868\u793a\u8c03\u7528\u51fd\u6570\u7684\u5bf9\u8c61\u3002\u90a3\u4e48\uff0c\u5982\u4f55\u786e\u5b9a\u51fd\u6570\u5bf9\u5e94\u7684\u5bf9\u8c61\u5462\uff1f\u4ee5\u4e0b\u662f\u4e00\u4e9b\u5e38\u89c1\u7684\u89c4\u5219\uff1a \u65b9\u6cd5\u8c03\u7528\uff1a\u5f53\u51fd\u6570\u4f5c\u4e3a\u5bf9\u8c61\u65b9\u6cd5\u8c03\u7528\u65f6\uff0cthis\u8868\u793a\u8be5\u5bf9\u8c61\u3002\u4f8b\u5982\uff1a const obj = { name: &#8220;john&#8221;, greet() { console.log(`hello, ${this.name}!`); } }; obj.greet(); \/\/ \u8f93\u51fa &#8220;hello, john!&#8221; \u767b\u5f55\u540e\u590d\u5236 \u666e\u901a\u51fd\u6570\u8c03\u7528\uff1a\u5f53\u51fd\u6570\u4f5c\u4e3a\u666e\u901a\u51fd\u6570\u8c03\u7528\u65f6\uff0cthis\u6307\u5411\u5168\u5c40\u5bf9\u8c61\uff08\u6d4f\u89c8\u5668\u4e2d\u4e3a&#8221;window&#8221;\uff0cnode.js\u4e2d\u4e3a&#8221;global&#8221;\uff09\u3002\u4f8b\u5982\uff1a function greet() { console.log(`hello, ${this.name}!`); } greet(); \/\/ \u8f93\u51fa\u62a5\u9519\uff1athis.name is undefined \u767b\u5f55\u540e\u590d\u5236 \u6784\u9020\u51fd\u6570\u8c03\u7528\uff1a\u5f53\u51fd\u6570\u4f5c\u4e3a\u6784\u9020\u51fd\u6570\u8c03\u7528\u65f6\uff0cthis\u6307\u5411\u65b0\u521b\u5efa\u7684\u5bf9\u8c61\u3002\u4f8b\u5982\uff1a function person(name) { this.name = name; } const person = new person(&#8220;jane&#8221;); console.log(person.name); \/\/ \u8f93\u51fa &#8220;jane&#8221; \u767b\u5f55\u540e\u590d\u5236 \u95f4\u63a5\u8c03\u7528\uff1a\u5f53\u51fd\u6570\u901a\u8fc7\u4ee3\u7406\u5bf9\u8c61\uff08\u5982&#8221;call&#8221;\u3001&#8221;apply&#8221;\u6216&#8221;bind&#8221;\u65b9\u6cd5\uff09\u8c03\u7528\u65f6\uff0cthis\u53ef\u4ee5\u624b\u52a8\u8bbe\u7f6e\u3002\u4f8b\u5982\uff1a const person [&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-2538","post","type-post","status-publish","format-standard","hentry","category-16"],"_links":{"self":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/2538","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=2538"}],"version-history":[{"count":0,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/2538\/revisions"}],"wp:attachment":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/media?parent=2538"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/categories?post=2538"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/tags?post=2538"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}