{"id":2118,"date":"2025-02-27T23:54:37","date_gmt":"2025-02-27T15:54:37","guid":{"rendered":"https:\/\/www.laixuexila.com\/?p=2118"},"modified":"2025-02-27T23:54:37","modified_gmt":"2025-02-27T15:54:37","slug":"javascript-%e5%af%b9%e8%b1%a1-2","status":"publish","type":"post","link":"https:\/\/www.laixuexila.com\/index.php\/2025\/02\/27\/javascript-%e5%af%b9%e8%b1%a1-2\/","title":{"rendered":"JavaScript \u5bf9\u8c61"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">\u5728 JavaScript \u4e2d\uff0c\u5bf9\u8c61\u662f\u4e00\u4e2a\u7528\u4e8e\u5b58\u50a8\u591a\u4e2a\u503c\u7684\u6570\u636e\u7ed3\u6784\u3002\u8fd9\u4e9b\u503c\u53ef\u4ee5\u662f\u4e0d\u540c\u7c7b\u578b\u7684\u6570\u636e\uff08\u5982\u6570\u5b57\u3001\u5b57\u7b26\u4e32\u3001\u6570\u7ec4\u3001\u51fd\u6570\u7b49\uff09\u3002\u5bf9\u8c61\u4ee5\u952e\u503c\u5bf9\u7684\u5f62\u5f0f\u5b58\u5728\uff0c\u5176\u4e2d\u952e\u662f\u5b57\u7b26\u4e32\u7c7b\u578b\uff0c\u503c\u53ef\u4ee5\u662f\u4efb\u4f55\u6570\u636e\u7c7b\u578b\uff0c\u5305\u62ec\u5176\u4ed6\u5bf9\u8c61\u6216\u51fd\u6570\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>1. \u521b\u5efa\u5bf9\u8c61<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u5bf9\u8c61\u53ef\u4ee5\u901a\u8fc7\u591a\u79cd\u65b9\u5f0f\u6765\u521b\u5efa\uff0c\u4ee5\u4e0b\u662f\u51e0\u79cd\u5e38\u89c1\u7684\u65b9\u5f0f\uff1a<\/p>\n\n\n\n<h4 class=\"wp-block-heading\"><strong>(1) \u4f7f\u7528\u5bf9\u8c61\u5b57\u9762\u91cf<\/strong><\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd9\u662f\u6700\u5e38\u89c1\u4e14\u6700\u7b80\u6d01\u7684\u65b9\u5f0f\uff0c\u4f7f\u7528\u82b1\u62ec\u53f7 <code>{}<\/code> \u6765\u521b\u5efa\u4e00\u4e2a\u5bf9\u8c61\uff0c\u5e76\u76f4\u63a5\u5b9a\u4e49\u952e\u503c\u5bf9\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>const person = {\n  name: 'John',\n  age: 30,\n  greet: function() {\n    console.log('Hello, ' + this.name);\n  }\n};\n\nconsole.log(person.name);  \/\/ \u8f93\u51fa \"John\"\nconsole.log(person.age);   \/\/ \u8f93\u51fa 30\nperson.greet();            \/\/ \u8f93\u51fa \"Hello, John\"<\/code><\/pre>\n\n\n\n<h4 class=\"wp-block-heading\"><strong>(2) \u4f7f\u7528 <code>new Object()<\/code><\/strong><\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u53ef\u4ee5\u901a\u8fc7 <code>new Object()<\/code> \u6765\u521b\u5efa\u4e00\u4e2a\u7a7a\u5bf9\u8c61\uff0c\u7136\u540e\u6dfb\u52a0\u5c5e\u6027\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>const person = new Object();\nperson.name = 'John';\nperson.age = 30;\nperson.greet = function() {\n  console.log('Hello, ' + this.name);\n};\n\nconsole.log(person.name);  \/\/ \u8f93\u51fa \"John\"\nconsole.log(person.age);   \/\/ \u8f93\u51fa 30\nperson.greet();            \/\/ \u8f93\u51fa \"Hello, John\"<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>2. \u5bf9\u8c61\u5c5e\u6027<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u5bf9\u8c61\u7684\u5c5e\u6027\u7531<strong>\u952e<\/strong>\uff08\u4e5f\u53eb\u505a<strong>\u5c5e\u6027\u540d<\/strong>\uff09\u548c<strong>\u503c<\/strong>\u7ec4\u6210\uff0c\u952e\u662f\u4e00\u4e2a\u5b57\u7b26\u4e32\uff0c\u800c\u503c\u53ef\u4ee5\u662f\u4efb\u4f55\u7c7b\u578b\u7684 JavaScript \u6570\u636e\u3002\u53ef\u4ee5\u4f7f\u7528\u70b9\uff08<code>.<\/code>\uff09\u7b26\u53f7\u6216\u65b9\u62ec\u53f7\uff08<code>[]<\/code>\uff09\u6765\u8bbf\u95ee\u5bf9\u8c61\u7684\u5c5e\u6027\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\"><strong>(1) \u8bbf\u95ee\u5bf9\u8c61\u5c5e\u6027<\/strong><\/h4>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u4f7f\u7528\u70b9\u7b26\u53f7\uff1a<\/li>\n<\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>  const person = { name: 'John', age: 30 };\n  console.log(person.name);  \/\/ \u8f93\u51fa \"John\"\n  console.log(person.age);   \/\/ \u8f93\u51fa 30<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u4f7f\u7528\u65b9\u62ec\u53f7\u7b26\u53f7\uff1a<\/li>\n<\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>  const person = { name: 'John', age: 30 };\n  console.log(person&#91;'name']);  \/\/ \u8f93\u51fa \"John\"\n  console.log(person&#91;'age']);   \/\/ \u8f93\u51fa 30<\/code><\/pre>\n\n\n\n<h4 class=\"wp-block-heading\"><strong>(2) \u52a8\u6001\u8bbf\u95ee\u5c5e\u6027<\/strong><\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u5f53\u5c5e\u6027\u540d\u5305\u542b\u7279\u6b8a\u5b57\u7b26\u6216\u9700\u8981\u52a8\u6001\u751f\u6210\u65f6\uff0c\u53ef\u4ee5\u4f7f\u7528\u65b9\u62ec\u53f7\u8bed\u6cd5\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>const person = { 'first name': 'John', age: 30 };\nconsole.log(person&#91;'first name']);  \/\/ \u8f93\u51fa \"John\"<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>3. \u4fee\u6539\u5bf9\u8c61\u5c5e\u6027<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u5bf9\u8c61\u7684\u5c5e\u6027\u503c\u53ef\u4ee5\u968f\u65f6\u88ab\u4fee\u6539\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>const person = { name: 'John', age: 30 };\nperson.age = 31;  \/\/ \u4fee\u6539 age \u5c5e\u6027\nconsole.log(person.age);  \/\/ \u8f93\u51fa 31<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>4. \u5220\u9664\u5bf9\u8c61\u5c5e\u6027<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u53ef\u4ee5\u4f7f\u7528 <code>delete<\/code> \u64cd\u4f5c\u7b26\u5220\u9664\u5bf9\u8c61\u7684\u5c5e\u6027\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>const person = { name: 'John', age: 30 };\ndelete person.age;  \/\/ \u5220\u9664 age \u5c5e\u6027\nconsole.log(person.age);  \/\/ \u8f93\u51fa undefined<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>5. \u5bf9\u8c61\u65b9\u6cd5<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u5bf9\u8c61\u4e0d\u4ec5\u53ef\u4ee5\u5305\u542b\u6570\u636e\uff0c\u8fd8\u53ef\u4ee5\u5305\u542b\u51fd\u6570\u3002\u5bf9\u8c61\u4e2d\u7684\u51fd\u6570\u88ab\u79f0\u4e3a<strong>\u65b9\u6cd5<\/strong>\u3002\u5728\u5b9a\u4e49\u65b9\u6cd5\u65f6\uff0c\u51fd\u6570\u53ef\u4ee5\u76f4\u63a5\u4f5c\u4e3a\u5bf9\u8c61\u7684\u5c5e\u6027\u6765\u521b\u5efa\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>const person = {\n  name: 'John',\n  age: 30,\n  greet: function() {\n    console.log('Hello, ' + this.name);\n  }\n};\n\nperson.greet();  \/\/ \u8f93\u51fa \"Hello, John\"<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728 ES6 \u4e2d\uff0c\u8fd8\u53ef\u4ee5\u4f7f\u7528\u7b80\u6d01\u7684\u8bed\u6cd5\u6765\u5b9a\u4e49\u65b9\u6cd5\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>const person = {\n  name: 'John',\n  age: 30,\n  greet() {\n    console.log('Hello, ' + this.name);\n  }\n};\n\nperson.greet();  \/\/ \u8f93\u51fa \"Hello, John\"<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>6. <code>this<\/code> \u5173\u952e\u5b57<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u5bf9\u8c61\u7684\u65b9\u6cd5\u4e2d\uff0c<code>this<\/code> \u5173\u952e\u5b57\u5f15\u7528\u7684\u662f\u5f53\u524d\u8c03\u7528\u8be5\u65b9\u6cd5\u7684\u5bf9\u8c61\u3002<code>this<\/code> \u7528\u6765\u8bbf\u95ee\u5bf9\u8c61\u4e2d\u7684\u5176\u4ed6\u5c5e\u6027\u548c\u65b9\u6cd5\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>const person = {\n  name: 'John',\n  age: 30,\n  greet() {\n    console.log('Hello, ' + this.name);  \/\/ `this` \u5f15\u7528\u7684\u662f person \u5bf9\u8c61\n  }\n};\n\nperson.greet();  \/\/ \u8f93\u51fa \"Hello, John\"<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>7. \u5bf9\u8c61\u904d\u5386<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u53ef\u4ee5\u4f7f\u7528 <code>for...in<\/code> \u5faa\u73af\u904d\u5386\u5bf9\u8c61\u7684\u6240\u6709\u53ef\u679a\u4e3e\u5c5e\u6027\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>const person = { name: 'John', age: 30, job: 'developer' };\n\nfor (let key in person) {\n  console.log(key + \": \" + person&#91;key]);\n}\n\/\/ \u8f93\u51fa:\n\/\/ name: John\n\/\/ age: 30\n\/\/ job: developer<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>8. \u5185\u90e8\u5bf9\u8c61\u5c5e\u6027<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">JavaScript \u4e2d\u7684\u5bf9\u8c61\u9664\u4e86\u53ef\u4ee5\u5305\u542b\u7528\u6237\u5b9a\u4e49\u7684\u5c5e\u6027\u5916\uff0c\u8fd8\u53ef\u4ee5\u5305\u542b\u4e00\u4e9b\u5185\u7f6e\u7684\u7279\u6b8a\u5c5e\u6027\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong><code>constructor<\/code><\/strong>\uff1a\u6307\u5411\u5bf9\u8c61\u7684\u6784\u9020\u51fd\u6570\u3002<\/li>\n\n\n\n<li><strong><code>prototype<\/code><\/strong>\uff1a\u6240\u6709\u5bf9\u8c61\u90fd\u62e5\u6709\u7684\u4e00\u4e2a\u5c5e\u6027\uff0c\u6307\u5411\u5bf9\u8c61\u7684\u539f\u578b\u3002<\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\"><strong>\u793a\u4f8b\uff1a\u4f7f\u7528 <code>constructor<\/code><\/strong><\/h4>\n\n\n\n<pre class=\"wp-block-code\"><code>const person = { name: 'John', age: 30 };\nconsole.log(person.constructor);  \/\/ \u8f93\u51fa \"function Object() { &#91;native code] }\"<\/code><\/pre>\n\n\n\n<h4 class=\"wp-block-heading\"><strong>\u793a\u4f8b\uff1a\u4f7f\u7528 <code>prototype<\/code><\/strong><\/h4>\n\n\n\n<pre class=\"wp-block-code\"><code>const person = { name: 'John', age: 30 };\nconsole.log(person.__proto__);  \/\/ \u8f93\u51fa Object.prototype<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>9. \u793a\u4f8b\uff1a\u4f7f\u7528\u5bf9\u8c61\u5b58\u50a8\u591a\u79cd\u7c7b\u578b\u7684\u6570\u636e<\/strong><\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>const car = {\n  brand: 'Tesla',\n  model: 'Model S',\n  year: 2022,\n  isElectric: true,\n  details: function() {\n    console.log(`${this.brand} ${this.model} (${this.year})`);\n  }\n};\n\nconsole.log(car.brand);       \/\/ \u8f93\u51fa \"Tesla\"\nconsole.log(car&#91;'model']);    \/\/ \u8f93\u51fa \"Model S\"\ncar.details();                \/\/ \u8f93\u51fa \"Tesla Model S (2022)\"<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>10. \u5bf9\u8c61\u548c\u6570\u7ec4\u7684\u533a\u522b<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u867d\u7136\u6570\u7ec4\u548c\u5bf9\u8c61\u90fd\u53ef\u4ee5\u5b58\u50a8\u591a\u4e2a\u503c\uff0c\u4f46\u5b83\u4eec\u7684\u4e3b\u8981\u533a\u522b\u5728\u4e8e\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u6570\u7ec4<\/strong>\uff1a\u503c\u662f\u6709\u5e8f\u7684\uff0c\u53ef\u4ee5\u901a\u8fc7\u7d22\u5f15\u6765\u8bbf\u95ee\u3002<\/li>\n\n\n\n<li><strong>\u5bf9\u8c61<\/strong>\uff1a\u503c\u662f\u65e0\u5e8f\u7684\uff0c\u53ef\u4ee5\u901a\u8fc7\u952e\uff08\u5b57\u7b26\u4e32\uff09\u6765\u8bbf\u95ee\u3002<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>\u603b\u7ed3<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>JavaScript \u5bf9\u8c61\u662f\u952e\u503c\u5bf9\u7684\u96c6\u5408\uff0c\u5176\u4e2d\u952e\u662f\u5b57\u7b26\u4e32\uff0c\u503c\u53ef\u4ee5\u662f\u4efb\u610f\u6570\u636e\u7c7b\u578b\u3002<\/li>\n\n\n\n<li>\u5bf9\u8c61\u53ef\u4ee5\u5305\u542b\u5c5e\u6027\u548c\u65b9\u6cd5\uff0c\u5c5e\u6027\u7528\u4e8e\u5b58\u50a8\u6570\u636e\uff0c\u65b9\u6cd5\u7528\u4e8e\u6267\u884c\u4efb\u52a1\u3002<\/li>\n\n\n\n<li>\u4f7f\u7528 <code>.<\/code> \u548c <code>[]<\/code> \u8bbf\u95ee\u548c\u4fee\u6539\u5bf9\u8c61\u7684\u5c5e\u6027\u3002<\/li>\n\n\n\n<li><code>this<\/code> \u5173\u952e\u5b57\u5f15\u7528\u5f53\u524d\u5bf9\u8c61\uff0c\u53ef\u4ee5\u8bbf\u95ee\u5bf9\u8c61\u7684\u5176\u4ed6\u5c5e\u6027\u548c\u65b9\u6cd5\u3002<\/li>\n\n\n\n<li>\u5bf9\u8c61\u53ef\u4ee5\u901a\u8fc7 <code>for...in<\/code> \u5faa\u73af\u8fdb\u884c\u904d\u5386\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u66f4\u591a\u8be6\u7ec6\u5185\u5bb9\u8bf7\u5173\u6ce8\u5176\u4ed6\u76f8\u5173\u6587\u7ae0\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5728 JavaScript \u4e2d\uff0c\u5bf9\u8c61\u662f\u4e00\u4e2a\u7528\u4e8e\u5b58\u50a8\u591a\u4e2a\u503c\u7684\u6570\u636e\u7ed3\u6784\u3002\u8fd9\u4e9b\u503c\u53ef\u4ee5\u662f\u4e0d\u540c\u7c7b\u578b\u7684\u6570\u636e\uff08\u5982\u6570\u5b57\u3001\u5b57\u7b26\u4e32\u3001 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[46],"tags":[],"class_list":["post-2118","post","type-post","status-publish","format-standard","hentry","category-javascript"],"_links":{"self":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/2118","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/comments?post=2118"}],"version-history":[{"count":1,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/2118\/revisions"}],"predecessor-version":[{"id":2119,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/2118\/revisions\/2119"}],"wp:attachment":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/media?parent=2118"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/categories?post=2118"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/tags?post=2118"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}