21 lines
64 KiB
HTML
21 lines
64 KiB
HTML
<!doctype html>
|
||
<html lang="en" dir="ltr" class="docs-wrapper docs-doc-page docs-version-current plugin-docs plugin-id-default docs-doc-id-book4/coding-apply-call-bind">
|
||
<head>
|
||
<meta charset="UTF-8">
|
||
<meta name="viewport" content="width=device-width,initial-scale=1">
|
||
<meta name="generator" content="Docusaurus v2.0.0-beta.18">
|
||
<link rel="search" type="application/opensearchdescription+xml" title="HZFE - 剑指前端 Offer" href="/awesome-interview/opensearch.xml">
|
||
<link rel="preconnect" href="https://hm.baidu.com">
|
||
<script>var _hmt=_hmt||[];!function(){var e=document.createElement("script");e.src="https://hm.baidu.com/hm.js?c7cd0fd77ac518cc6ef46461cdc9524b";var c=document.getElementsByTagName("script")[0];c.parentNode.insertBefore(e,c)}()</script>
|
||
<script src="https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js" async data-ad-client="ca-pub-9889934432771967"></script>
|
||
<script src="https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js?client=ca-pub-9889934432771967" async crossorigin="anonymous"></script><title data-rh="true">实现 apply/call/bind | HZFE - 剑指前端 Offer</title><meta data-rh="true" name="twitter:card" content="summary_large_image"><meta data-rh="true" property="og:url" content="https://febook.hzfe.org/awesome-interview/book4/coding-apply-call-bind"><meta data-rh="true" name="docusaurus_locale" content="en"><meta data-rh="true" name="docsearch:language" content="en"><meta data-rh="true" name="docusaurus_version" content="current"><meta data-rh="true" name="docusaurus_tag" content="docs-default-current"><meta data-rh="true" name="docsearch:version" content="current"><meta data-rh="true" name="docsearch:docusaurus_tag" content="docs-default-current"><meta data-rh="true" property="og:title" content="实现 apply/call/bind | HZFE - 剑指前端 Offer"><meta data-rh="true" name="description" content="apply"><meta data-rh="true" property="og:description" content="apply"><link data-rh="true" rel="icon" href="/awesome-interview/img/favicon.ico"><link data-rh="true" rel="canonical" href="https://febook.hzfe.org/awesome-interview/book4/coding-apply-call-bind"><link data-rh="true" rel="alternate" href="https://febook.hzfe.org/awesome-interview/book4/coding-apply-call-bind" hreflang="en"><link data-rh="true" rel="alternate" href="https://febook.hzfe.org/awesome-interview/book4/coding-apply-call-bind" hreflang="x-default"><link data-rh="true" rel="preconnect" href="https://PED5MQGL7T-dsn.algolia.net" crossorigin="anonymous"><link rel="stylesheet" href="/awesome-interview/assets/css/styles.62902d4b.css">
|
||
<link rel="preload" href="/awesome-interview/assets/js/runtime~main.16895322.js" as="script">
|
||
<link rel="preload" href="/awesome-interview/assets/js/main.a6349f88.js" as="script">
|
||
</head>
|
||
<body class="navigation-with-keyboard">
|
||
<script>!function(){function t(t){document.documentElement.setAttribute("data-theme",t)}var e=function(){var t=null;try{t=localStorage.getItem("theme")}catch(t){}return t}();t(null!==e?e:"light")}()</script><div id="__docusaurus">
|
||
<div role="region"><a href="#" class="skipToContent_ZgBM">Skip to main content</a></div><nav class="navbar navbar--fixed-top navbarHideable_ObN2"><div class="navbar__inner"><div class="navbar__items"><button aria-label="Navigation bar toggle" class="navbar__toggle clean-btn" type="button" tabindex="0"><svg width="30" height="30" viewBox="0 0 30 30" aria-hidden="true"><path stroke="currentColor" stroke-linecap="round" stroke-miterlimit="10" stroke-width="2" d="M4 7h22M4 15h22M4 23h22"></path></svg></button><a class="navbar__brand" href="/awesome-interview/"><div class="navbar__logo"><img src="/awesome-interview/img/badge.svg" alt="HZFE" class="themedImage_W2Cr themedImage--light_TfLj"><img src="/awesome-interview/img/badge.svg" alt="HZFE" class="themedImage_W2Cr themedImage--dark_oUvU"></div><b class="navbar__title">剑指前端 Offer</b></a></div><div class="navbar__items navbar__items--right"><a href="https://github.com/hzfe/awesome-interview" target="_blank" rel="noopener noreferrer" class="navbar__item navbar__link">GitHub<svg width="13.5" height="13.5" aria-hidden="true" viewBox="0 0 24 24" class="iconExternalLink_I5OW"><path fill="currentColor" d="M21 13v10h-21v-19h12v2h-10v15h17v-8h2zm3-12h-10.988l4.035 4-6.977 7.07 2.828 2.828 6.977-7.07 4.125 4.172v-11z"></path></svg></a><div class="searchBox_qEbK"><button type="button" class="DocSearch DocSearch-Button" aria-label="Search"><span class="DocSearch-Button-Container"><svg width="20" height="20" class="DocSearch-Search-Icon" viewBox="0 0 20 20"><path d="M14.386 14.386l4.0877 4.0877-4.0877-4.0877c-2.9418 2.9419-7.7115 2.9419-10.6533 0-2.9419-2.9418-2.9419-7.7115 0-10.6533 2.9418-2.9419 7.7115-2.9419 10.6533 0 2.9419 2.9418 2.9419 7.7115 0 10.6533z" stroke="currentColor" fill="none" fill-rule="evenodd" stroke-linecap="round" stroke-linejoin="round"></path></svg><span class="DocSearch-Button-Placeholder">Search</span></span><span class="DocSearch-Button-Keys"></span></button></div></div></div><div role="presentation" class="navbar-sidebar__backdrop"></div></nav><div class="main-wrapper"><div class="docPage_P2Lg"><button aria-label="Scroll back to top" class="clean-btn theme-back-to-top-button backToTopButton_RiI4" type="button"></button><aside class="theme-doc-sidebar-container docSidebarContainer_rKC_"><div class="sidebar_RiAD sidebarWithHideableNavbar_d0QC"><a tabindex="-1" class="sidebarLogo_YUvz" href="/awesome-interview/"><img src="/awesome-interview/img/badge.svg" alt="HZFE" class="themedImage_W2Cr themedImage--light_TfLj"><img src="/awesome-interview/img/badge.svg" alt="HZFE" class="themedImage_W2Cr themedImage--dark_oUvU"><b>剑指前端 Offer</b></a><nav class="menu thin-scrollbar menu_izAj"><ul class="theme-doc-sidebar-menu menu__list"><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-1 menu__list-item"><a class="menu__link" href="/awesome-interview/about">关于我们</a></li><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-1 menu__list-item"><a class="menu__link" href="/awesome-interview/">前言</a></li><li class="theme-doc-sidebar-item-category theme-doc-sidebar-item-category-level-1 menu__list-item menu__list-item--collapsed"><div class="menu__list-item-collapsible"><a class="menu__link menu__link--sublist menu__link--sublist-caret" aria-expanded="false" href="/awesome-interview/book1/browser-cross-origin">模拟题一</a></div></li><li class="theme-doc-sidebar-item-category theme-doc-sidebar-item-category-level-1 menu__list-item menu__list-item--collapsed"><div class="menu__list-item-collapsible"><a class="menu__link menu__link--sublist menu__link--sublist-caret" aria-expanded="false" href="/awesome-interview/book2/browser-render-mechanism">模拟题二</a></div></li><li class="theme-doc-sidebar-item-category theme-doc-sidebar-item-category-level-1 menu__list-item menu__list-item--collapsed"><div class="menu__list-item-collapsible"><a class="menu__link menu__link--sublist menu__link--sublist-caret" aria-expanded="false" href="/awesome-interview/book3/browser-event-loop">模拟题三</a></div></li><li class="theme-doc-sidebar-item-category theme-doc-sidebar-item-category-level-1 menu__list-item"><div class="menu__list-item-collapsible"><a class="menu__link menu__link--sublist menu__link--sublist-caret menu__link--active" aria-expanded="true" href="/awesome-interview/book4/browser-router">模拟题四</a></div><ul style="display:block;overflow:visible;height:auto" class="menu__list"><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-2 menu__list-item"><a class="menu__link" tabindex="0" href="/awesome-interview/book4/browser-router">浏览器：前端路由实现</a></li><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-2 menu__list-item"><a class="menu__link" tabindex="0" href="/awesome-interview/book4/browser-local-storage">浏览器：本地存储方式及场景</a></li><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-2 menu__list-item"><a class="menu__link" tabindex="0" href="/awesome-interview/book4/engineer-front-end-testing">工程化：如何对前端代码实施测试</a></li><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-2 menu__list-item"><a class="menu__link" tabindex="0" href="/awesome-interview/book4/engineer-mfa">工程化：谈谈微前端</a></li><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-2 menu__list-item"><a class="menu__link" tabindex="0" href="/awesome-interview/book4/frame-react-event-mechanism">框架：React 事件机制原理</a></li><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-2 menu__list-item"><a class="menu__link" tabindex="0" href="/awesome-interview/book4/frame-react-vs-vue">框架：谈谈 React 和 Vue 的区别</a></li><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-2 menu__list-item"><a class="menu__link" tabindex="0" href="/awesome-interview/book4/js-ts-generics">基础：什么是 TypeScript 泛型</a></li><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-2 menu__list-item"><a class="menu__link" tabindex="0" href="/awesome-interview/book4/css-vertical-horizontal-center">样式：水平垂直居中方案</a></li><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-2 menu__list-item"><a class="menu__link menu__link--active" aria-current="page" tabindex="0" href="/awesome-interview/book4/coding-apply-call-bind">编码：实现 apply/call/bind</a></li><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-2 menu__list-item"><a class="menu__link" tabindex="0" href="/awesome-interview/book4/array-repeat-number">算法：找到数组中重复的数字</a></li></ul></li></ul></nav><button type="button" title="Collapse sidebar" aria-label="Collapse sidebar" class="button button--secondary button--outline collapseSidebarButton_FykI"><svg width="20" height="20" aria-hidden="true" class="collapseSidebarButtonIcon_DTRl"><g fill="#7a7a7a"><path d="M9.992 10.023c0 .2-.062.399-.172.547l-4.996 7.492a.982.982 0 01-.828.454H1c-.55 0-1-.453-1-1 0-.2.059-.403.168-.551l4.629-6.942L.168 3.078A.939.939 0 010 2.528c0-.548.45-.997 1-.997h2.996c.352 0 .649.18.828.45L9.82 9.472c.11.148.172.347.172.55zm0 0"></path><path d="M19.98 10.023c0 .2-.058.399-.168.547l-4.996 7.492a.987.987 0 01-.828.454h-3c-.547 0-.996-.453-.996-1 0-.2.059-.403.168-.551l4.625-6.942-4.625-6.945a.939.939 0 01-.168-.55 1 1 0 01.996-.997h3c.348 0 .649.18.828.45l4.996 7.492c.11.148.168.347.168.55zm0 0"></path></g></svg></button></div></aside><main class="docMainContainer_TCnq"><div class="container padding-top--md padding-bottom--lg"><div class="row"><div class="col docItemCol_DM6M"><div class="docItemContainer_vinB"><article><nav class="theme-doc-breadcrumbs breadcrumbsContainer_Xlws" aria-label="breadcrumbs"><ul class="breadcrumbs" itemscope="" itemtype="https://schema.org/BreadcrumbList"><li class="breadcrumbs__item"><a class="breadcrumbs__link" href="/awesome-interview/">🏠</a></li><li itemscope="" itemprop="itemListElement" itemtype="https://schema.org/ListItem" class="breadcrumbs__item"><span class="breadcrumbs__link" itemprop="item name">模拟题四</span><meta itemprop="position" content="1"></li><li itemscope="" itemprop="itemListElement" itemtype="https://schema.org/ListItem" class="breadcrumbs__item breadcrumbs__item--active"><span class="breadcrumbs__link" itemprop="item name">编码：实现 apply/call/bind</span><meta itemprop="position" content="2"></li></ul></nav><div class="tocCollapsible_jdIR theme-doc-toc-mobile tocMobile_TmEX"><button type="button" class="clean-btn tocCollapsibleButton_Fzxq">On this page</button></div><div class="theme-doc-markdown markdown"><h1>实现 apply/call/bind</h1><h2 class="anchor anchorWithHideOnScrollNavbar_R0VQ" id="apply">apply<a class="hash-link" href="#apply" title="Direct link to heading"></a></h2><h3 class="anchor anchorWithHideOnScrollNavbar_R0VQ" id="1-语法">1. 语法<a class="hash-link" href="#1-语法" title="Direct link to heading"></a></h3><div class="codeBlockContainer_I0IT language-jsx theme-code-block"><div class="codeBlockContent_wNvx" style="color:#393A34;background-color:#f6f8fa"><pre tabindex="0" class="prism-code language-jsx codeBlock_jd64 thin-scrollbar"><code class="codeBlockLines_mRuA"><span class="token-line" style="color:#393A34"><span class="token function" style="color:#d73a49">func</span><span class="token punctuation" style="color:#393A34">.</span><span class="token function" style="color:#d73a49">apply</span><span class="token punctuation" style="color:#393A34">(</span><span class="token plain">thisArg</span><span class="token punctuation" style="color:#393A34">,</span><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">[</span><span class="token plain">argsArray</span><span class="token punctuation" style="color:#393A34">]</span><span class="token punctuation" style="color:#393A34">)</span><span class="token punctuation" style="color:#393A34">;</span><br></span></code></pre><button type="button" aria-label="Copy code to clipboard" title="Copy" class="copyButton_eDfN clean-btn"><span class="copyButtonIcons_W9eQ" aria-hidden="true"><svg class="copyButtonIcon_XEyF" viewBox="0 0 24 24"><path d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg class="copyButtonSuccessIcon_i9w9" viewBox="0 0 24 24"><path d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div><p><strong>参数</strong></p><p><code>thisArg</code></p><p>在 func 函数运行时使用的 this 值。</p><p><code>argsArray</code></p><p>一个数组或者类数组对象，其中的数组元素将作为单独的参数传给 func 函数。如果该参数的值为 null 或 undefined，则表示不需要传入任何参数。</p><p><strong>返回值</strong></p><p>使用指定的 this 值和参数调用函数的结果。</p><h3 class="anchor anchorWithHideOnScrollNavbar_R0VQ" id="2-流程图">2. 流程图<a class="hash-link" href="#2-流程图" title="Direct link to heading"></a></h3><p><img loading="lazy" src="https://user-images.githubusercontent.com/17525377/147632530-34eac628-0bbd-4025-890b-2596a421263d.jpg" alt="apply" class="img_E7b_"></p><h3 class="anchor anchorWithHideOnScrollNavbar_R0VQ" id="3-编写代码">3. 编写代码<a class="hash-link" href="#3-编写代码" title="Direct link to heading"></a></h3><div class="codeBlockContainer_I0IT language-jsx theme-code-block"><div class="codeBlockContent_wNvx" style="color:#393A34;background-color:#f6f8fa"><pre tabindex="0" class="prism-code language-jsx codeBlock_jd64 thin-scrollbar"><code class="codeBlockLines_mRuA"><span class="token-line" style="color:#393A34"><span class="token class-name">Function</span><span class="token punctuation" style="color:#393A34">.</span><span class="token plain">prototype</span><span class="token punctuation" style="color:#393A34">.</span><span class="token function-variable function" style="color:#d73a49">apply</span><span class="token plain"> </span><span class="token operator" style="color:#393A34">=</span><span class="token plain"> </span><span class="token keyword" style="color:#00009f">function</span><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">(</span><span class="token parameter">thisArg</span><span class="token parameter punctuation" style="color:#393A34">,</span><span class="token parameter"> argsArray</span><span class="token punctuation" style="color:#393A34">)</span><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token keyword" style="color:#00009f">if</span><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">(</span><span class="token keyword" style="color:#00009f">typeof</span><span class="token plain"> </span><span class="token keyword" style="color:#00009f">this</span><span class="token plain"> </span><span class="token operator" style="color:#393A34">!==</span><span class="token plain"> </span><span class="token string" style="color:#e3116c">"function"</span><span class="token punctuation" style="color:#393A34">)</span><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token keyword" style="color:#00009f">throw</span><span class="token plain"> </span><span class="token keyword" style="color:#00009f">new</span><span class="token plain"> </span><span class="token class-name">TypeError</span><span class="token punctuation" style="color:#393A34">(</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token string" style="color:#e3116c">"Function.prototype.apply was called on which is not a function"</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">)</span><span class="token punctuation" style="color:#393A34">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">}</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token keyword" style="color:#00009f">if</span><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">(</span><span class="token plain">thisArg </span><span class="token operator" style="color:#393A34">===</span><span class="token plain"> </span><span class="token keyword" style="color:#00009f">undefined</span><span class="token plain"> </span><span class="token operator" style="color:#393A34">||</span><span class="token plain"> thisArg </span><span class="token operator" style="color:#393A34">===</span><span class="token plain"> </span><span class="token keyword" style="color:#00009f">null</span><span class="token punctuation" style="color:#393A34">)</span><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> thisArg </span><span class="token operator" style="color:#393A34">=</span><span class="token plain"> window</span><span class="token punctuation" style="color:#393A34">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">}</span><span class="token plain"> </span><span class="token keyword" style="color:#00009f">else</span><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> thisArg </span><span class="token operator" style="color:#393A34">=</span><span class="token plain"> </span><span class="token function" style="color:#d73a49">Object</span><span class="token punctuation" style="color:#393A34">(</span><span class="token plain">thisArg</span><span class="token punctuation" style="color:#393A34">)</span><span class="token punctuation" style="color:#393A34">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">}</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token comment" style="color:#999988;font-style:italic">// 将 func 放入 thisArg 内，这样在调用 thisArg[func] 时 this 自然就指向了 thisArg</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token keyword" style="color:#00009f">const</span><span class="token plain"> func </span><span class="token operator" style="color:#393A34">=</span><span class="token plain"> </span><span class="token function" style="color:#d73a49">Symbol</span><span class="token punctuation" style="color:#393A34">(</span><span class="token string" style="color:#e3116c">"func"</span><span class="token punctuation" style="color:#393A34">)</span><span class="token punctuation" style="color:#393A34">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> thisArg</span><span class="token punctuation" style="color:#393A34">[</span><span class="token plain">func</span><span class="token punctuation" style="color:#393A34">]</span><span class="token plain"> </span><span class="token operator" style="color:#393A34">=</span><span class="token plain"> </span><span class="token keyword" style="color:#00009f">this</span><span class="token punctuation" style="color:#393A34">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token keyword" style="color:#00009f">let</span><span class="token plain"> result</span><span class="token punctuation" style="color:#393A34">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token keyword" style="color:#00009f">if</span><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">(</span><span class="token plain">argsArray </span><span class="token operator" style="color:#393A34">&&</span><span class="token plain"> </span><span class="token keyword" style="color:#00009f">typeof</span><span class="token plain"> argsArray </span><span class="token operator" style="color:#393A34">===</span><span class="token plain"> </span><span class="token string" style="color:#e3116c">"object"</span><span class="token plain"> </span><span class="token operator" style="color:#393A34">&&</span><span class="token plain"> </span><span class="token string" style="color:#e3116c">"length"</span><span class="token plain"> </span><span class="token keyword" style="color:#00009f">in</span><span class="token plain"> argsArray</span><span class="token punctuation" style="color:#393A34">)</span><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token comment" style="color:#999988;font-style:italic">// 此处使用 Array.from 包裹让其支持形如 { length: 1, 0: 1 } 这样的类数组对象，直接对 argsArray 展开将会执行出错</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> result </span><span class="token operator" style="color:#393A34">=</span><span class="token plain"> thisArg</span><span class="token punctuation" style="color:#393A34">[</span><span class="token plain">func</span><span class="token punctuation" style="color:#393A34">]</span><span class="token punctuation" style="color:#393A34">(</span><span class="token operator" style="color:#393A34">...</span><span class="token plain">Array</span><span class="token punctuation" style="color:#393A34">.</span><span class="token function" style="color:#d73a49">from</span><span class="token punctuation" style="color:#393A34">(</span><span class="token plain">argsArray</span><span class="token punctuation" style="color:#393A34">)</span><span class="token punctuation" style="color:#393A34">)</span><span class="token punctuation" style="color:#393A34">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">}</span><span class="token plain"> </span><span class="token keyword" style="color:#00009f">else</span><span class="token plain"> </span><span class="token keyword" style="color:#00009f">if</span><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">(</span><span class="token plain">argsArray </span><span class="token operator" style="color:#393A34">===</span><span class="token plain"> </span><span class="token keyword" style="color:#00009f">undefined</span><span class="token plain"> </span><span class="token operator" style="color:#393A34">||</span><span class="token plain"> argsArray </span><span class="token operator" style="color:#393A34">===</span><span class="token plain"> </span><span class="token keyword" style="color:#00009f">null</span><span class="token punctuation" style="color:#393A34">)</span><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> result </span><span class="token operator" style="color:#393A34">=</span><span class="token plain"> thisArg</span><span class="token punctuation" style="color:#393A34">[</span><span class="token plain">func</span><span class="token punctuation" style="color:#393A34">]</span><span class="token punctuation" style="color:#393A34">(</span><span class="token punctuation" style="color:#393A34">)</span><span class="token punctuation" style="color:#393A34">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">}</span><span class="token plain"> </span><span class="token keyword" style="color:#00009f">else</span><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token keyword" style="color:#00009f">throw</span><span class="token plain"> </span><span class="token keyword" style="color:#00009f">new</span><span class="token plain"> </span><span class="token class-name">TypeError</span><span class="token punctuation" style="color:#393A34">(</span><span class="token string" style="color:#e3116c">"CreateListFromArrayLike called on non-object"</span><span class="token punctuation" style="color:#393A34">)</span><span class="token punctuation" style="color:#393A34">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">}</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token keyword" style="color:#00009f">delete</span><span class="token plain"> thisArg</span><span class="token punctuation" style="color:#393A34">[</span><span class="token plain">func</span><span class="token punctuation" style="color:#393A34">]</span><span class="token punctuation" style="color:#393A34">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token keyword" style="color:#00009f">return</span><span class="token plain"> result</span><span class="token punctuation" style="color:#393A34">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"></span><span class="token punctuation" style="color:#393A34">}</span><span class="token punctuation" style="color:#393A34">;</span><br></span></code></pre><button type="button" aria-label="Copy code to clipboard" title="Copy" class="copyButton_eDfN clean-btn"><span class="copyButtonIcons_W9eQ" aria-hidden="true"><svg class="copyButtonIcon_XEyF" viewBox="0 0 24 24"><path d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg class="copyButtonSuccessIcon_i9w9" viewBox="0 0 24 24"><path d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div><h2 class="anchor anchorWithHideOnScrollNavbar_R0VQ" id="call">call<a class="hash-link" href="#call" title="Direct link to heading"></a></h2><h3 class="anchor anchorWithHideOnScrollNavbar_R0VQ" id="1-语法-1">1. 语法<a class="hash-link" href="#1-语法-1" title="Direct link to heading"></a></h3><div class="codeBlockContainer_I0IT language-jsx theme-code-block"><div class="codeBlockContent_wNvx" style="color:#393A34;background-color:#f6f8fa"><pre tabindex="0" class="prism-code language-jsx codeBlock_jd64 thin-scrollbar"><code class="codeBlockLines_mRuA"><span class="token-line" style="color:#393A34"><span class="token function" style="color:#d73a49">func</span><span class="token punctuation" style="color:#393A34">.</span><span class="token function" style="color:#d73a49">call</span><span class="token punctuation" style="color:#393A34">(</span><span class="token plain">thisArg</span><span class="token punctuation" style="color:#393A34">,</span><span class="token plain"> arg1</span><span class="token punctuation" style="color:#393A34">,</span><span class="token plain"> arg2</span><span class="token punctuation" style="color:#393A34">,</span><span class="token plain"> </span><span class="token operator" style="color:#393A34">...</span><span class="token punctuation" style="color:#393A34">)</span><br></span></code></pre><button type="button" aria-label="Copy code to clipboard" title="Copy" class="copyButton_eDfN clean-btn"><span class="copyButtonIcons_W9eQ" aria-hidden="true"><svg class="copyButtonIcon_XEyF" viewBox="0 0 24 24"><path d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg class="copyButtonSuccessIcon_i9w9" viewBox="0 0 24 24"><path d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div><p><strong>参数</strong></p><p><code>thisArg</code></p><p>在 func 函数运行时使用的 this 值。</p><p><code>arg1, arg2, ...</code></p><p>指定的参数列表。</p><p><strong>返回值</strong></p><p>使用指定的 this 值和参数调用函数的结果。</p><h3 class="anchor anchorWithHideOnScrollNavbar_R0VQ" id="2-流程图-1">2. 流程图<a class="hash-link" href="#2-流程图-1" title="Direct link to heading"></a></h3><p><img loading="lazy" src="https://user-images.githubusercontent.com/17525377/147632668-575c348e-96f5-4088-8cee-38e3ee70a2cc.jpg" alt="call" class="img_E7b_"></p><h3 class="anchor anchorWithHideOnScrollNavbar_R0VQ" id="3-编写代码-1">3. 编写代码<a class="hash-link" href="#3-编写代码-1" title="Direct link to heading"></a></h3><div class="codeBlockContainer_I0IT language-jsx theme-code-block"><div class="codeBlockContent_wNvx" style="color:#393A34;background-color:#f6f8fa"><pre tabindex="0" class="prism-code language-jsx codeBlock_jd64 thin-scrollbar"><code class="codeBlockLines_mRuA"><span class="token-line" style="color:#393A34"><span class="token class-name">Function</span><span class="token punctuation" style="color:#393A34">.</span><span class="token plain">prototype</span><span class="token punctuation" style="color:#393A34">.</span><span class="token function-variable function" style="color:#d73a49">call</span><span class="token plain"> </span><span class="token operator" style="color:#393A34">=</span><span class="token plain"> </span><span class="token keyword" style="color:#00009f">function</span><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">(</span><span class="token parameter">thisArg</span><span class="token parameter punctuation" style="color:#393A34">,</span><span class="token parameter"> </span><span class="token parameter operator" style="color:#393A34">...</span><span class="token parameter">argsArray</span><span class="token punctuation" style="color:#393A34">)</span><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token keyword" style="color:#00009f">if</span><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">(</span><span class="token keyword" style="color:#00009f">typeof</span><span class="token plain"> </span><span class="token keyword" style="color:#00009f">this</span><span class="token plain"> </span><span class="token operator" style="color:#393A34">!==</span><span class="token plain"> </span><span class="token string" style="color:#e3116c">"function"</span><span class="token punctuation" style="color:#393A34">)</span><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token keyword" style="color:#00009f">throw</span><span class="token plain"> </span><span class="token keyword" style="color:#00009f">new</span><span class="token plain"> </span><span class="token class-name">TypeError</span><span class="token punctuation" style="color:#393A34">(</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token string" style="color:#e3116c">"Function.prototype.call was called on which is not a function"</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">)</span><span class="token punctuation" style="color:#393A34">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">}</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token keyword" style="color:#00009f">if</span><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">(</span><span class="token plain">thisArg </span><span class="token operator" style="color:#393A34">===</span><span class="token plain"> </span><span class="token keyword" style="color:#00009f">undefined</span><span class="token plain"> </span><span class="token operator" style="color:#393A34">||</span><span class="token plain"> thisArg </span><span class="token operator" style="color:#393A34">===</span><span class="token plain"> </span><span class="token keyword" style="color:#00009f">null</span><span class="token punctuation" style="color:#393A34">)</span><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> thisArg </span><span class="token operator" style="color:#393A34">=</span><span class="token plain"> window</span><span class="token punctuation" style="color:#393A34">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">}</span><span class="token plain"> </span><span class="token keyword" style="color:#00009f">else</span><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> thisArg </span><span class="token operator" style="color:#393A34">=</span><span class="token plain"> </span><span class="token function" style="color:#d73a49">Object</span><span class="token punctuation" style="color:#393A34">(</span><span class="token plain">thisArg</span><span class="token punctuation" style="color:#393A34">)</span><span class="token punctuation" style="color:#393A34">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">}</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token comment" style="color:#999988;font-style:italic">// 将 func 放入 thisArg 内，这样在调用 thisArg[func] 时 this 自然就指向了 thisArg</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token keyword" style="color:#00009f">const</span><span class="token plain"> func </span><span class="token operator" style="color:#393A34">=</span><span class="token plain"> </span><span class="token function" style="color:#d73a49">Symbol</span><span class="token punctuation" style="color:#393A34">(</span><span class="token string" style="color:#e3116c">"func"</span><span class="token punctuation" style="color:#393A34">)</span><span class="token punctuation" style="color:#393A34">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> thisArg</span><span class="token punctuation" style="color:#393A34">[</span><span class="token plain">func</span><span class="token punctuation" style="color:#393A34">]</span><span class="token plain"> </span><span class="token operator" style="color:#393A34">=</span><span class="token plain"> </span><span class="token keyword" style="color:#00009f">this</span><span class="token punctuation" style="color:#393A34">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token keyword" style="color:#00009f">let</span><span class="token plain"> result</span><span class="token punctuation" style="color:#393A34">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token keyword" style="color:#00009f">if</span><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">(</span><span class="token plain">argsArray</span><span class="token punctuation" style="color:#393A34">.</span><span class="token plain">length</span><span class="token punctuation" style="color:#393A34">)</span><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> result </span><span class="token operator" style="color:#393A34">=</span><span class="token plain"> thisArg</span><span class="token punctuation" style="color:#393A34">[</span><span class="token plain">func</span><span class="token punctuation" style="color:#393A34">]</span><span class="token punctuation" style="color:#393A34">(</span><span class="token operator" style="color:#393A34">...</span><span class="token plain">argsArray</span><span class="token punctuation" style="color:#393A34">)</span><span class="token punctuation" style="color:#393A34">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">}</span><span class="token plain"> </span><span class="token keyword" style="color:#00009f">else</span><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> result </span><span class="token operator" style="color:#393A34">=</span><span class="token plain"> thisArg</span><span class="token punctuation" style="color:#393A34">[</span><span class="token plain">func</span><span class="token punctuation" style="color:#393A34">]</span><span class="token punctuation" style="color:#393A34">(</span><span class="token punctuation" style="color:#393A34">)</span><span class="token punctuation" style="color:#393A34">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">}</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token keyword" style="color:#00009f">delete</span><span class="token plain"> thisArg</span><span class="token punctuation" style="color:#393A34">[</span><span class="token plain">func</span><span class="token punctuation" style="color:#393A34">]</span><span class="token punctuation" style="color:#393A34">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token keyword" style="color:#00009f">return</span><span class="token plain"> result</span><span class="token punctuation" style="color:#393A34">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"></span><span class="token punctuation" style="color:#393A34">}</span><span class="token punctuation" style="color:#393A34">;</span><br></span></code></pre><button type="button" aria-label="Copy code to clipboard" title="Copy" class="copyButton_eDfN clean-btn"><span class="copyButtonIcons_W9eQ" aria-hidden="true"><svg class="copyButtonIcon_XEyF" viewBox="0 0 24 24"><path d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg class="copyButtonSuccessIcon_i9w9" viewBox="0 0 24 24"><path d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div><h2 class="anchor anchorWithHideOnScrollNavbar_R0VQ" id="bind">bind<a class="hash-link" href="#bind" title="Direct link to heading"></a></h2><h3 class="anchor anchorWithHideOnScrollNavbar_R0VQ" id="1-语法-2">1. 语法<a class="hash-link" href="#1-语法-2" title="Direct link to heading"></a></h3><div class="codeBlockContainer_I0IT language-jsx theme-code-block"><div class="codeBlockContent_wNvx" style="color:#393A34;background-color:#f6f8fa"><pre tabindex="0" class="prism-code language-jsx codeBlock_jd64 thin-scrollbar"><code class="codeBlockLines_mRuA"><span class="token-line" style="color:#393A34"><span class="token function" style="color:#d73a49">func</span><span class="token punctuation" style="color:#393A34">.</span><span class="token function" style="color:#d73a49">bind</span><span class="token punctuation" style="color:#393A34">(</span><span class="token plain">thisArg</span><span class="token punctuation" style="color:#393A34">[</span><span class="token punctuation" style="color:#393A34">,</span><span class="token plain"> arg1</span><span class="token punctuation" style="color:#393A34">[</span><span class="token punctuation" style="color:#393A34">,</span><span class="token plain"> arg2</span><span class="token punctuation" style="color:#393A34">[</span><span class="token punctuation" style="color:#393A34">,</span><span class="token plain"> </span><span class="token operator" style="color:#393A34">...</span><span class="token punctuation" style="color:#393A34">]</span><span class="token punctuation" style="color:#393A34">]</span><span class="token punctuation" style="color:#393A34">]</span><span class="token punctuation" style="color:#393A34">)</span><br></span></code></pre><button type="button" aria-label="Copy code to clipboard" title="Copy" class="copyButton_eDfN clean-btn"><span class="copyButtonIcons_W9eQ" aria-hidden="true"><svg class="copyButtonIcon_XEyF" viewBox="0 0 24 24"><path d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg class="copyButtonSuccessIcon_i9w9" viewBox="0 0 24 24"><path d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div><p><strong>参数</strong></p><p><code>thisArg</code></p><p>调用绑定函数时作为 this 参数传递给目标函数的值。 如果使用 new 运算符构造绑定函数，则忽略该值。</p><p><code>arg1, arg2, ...</code></p><p>当目标函数被调用时，被预置入绑定函数的参数列表中的参数。</p><p><strong>返回值</strong></p><p>返回一个原函数的拷贝，并拥有指定的 this 值和初始参数。</p><h3 class="anchor anchorWithHideOnScrollNavbar_R0VQ" id="2-流程图-2">2. 流程图<a class="hash-link" href="#2-流程图-2" title="Direct link to heading"></a></h3><p><img loading="lazy" src="https://user-images.githubusercontent.com/17525377/147632692-d7d335a7-a236-4bee-85a6-51aedbf285b9.jpg" alt="bind" class="img_E7b_"></p><h3 class="anchor anchorWithHideOnScrollNavbar_R0VQ" id="3-编写代码-2">3. 编写代码<a class="hash-link" href="#3-编写代码-2" title="Direct link to heading"></a></h3><div class="codeBlockContainer_I0IT language-jsx theme-code-block"><div class="codeBlockContent_wNvx" style="color:#393A34;background-color:#f6f8fa"><pre tabindex="0" class="prism-code language-jsx codeBlock_jd64 thin-scrollbar"><code class="codeBlockLines_mRuA"><span class="token-line" style="color:#393A34"><span class="token class-name">Function</span><span class="token punctuation" style="color:#393A34">.</span><span class="token plain">prototype</span><span class="token punctuation" style="color:#393A34">.</span><span class="token function-variable function" style="color:#d73a49">bind</span><span class="token plain"> </span><span class="token operator" style="color:#393A34">=</span><span class="token plain"> </span><span class="token keyword" style="color:#00009f">function</span><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">(</span><span class="token parameter">thisArg</span><span class="token parameter punctuation" style="color:#393A34">,</span><span class="token parameter"> </span><span class="token parameter operator" style="color:#393A34">...</span><span class="token parameter">argsArray</span><span class="token punctuation" style="color:#393A34">)</span><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token keyword" style="color:#00009f">if</span><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">(</span><span class="token keyword" style="color:#00009f">typeof</span><span class="token plain"> </span><span class="token keyword" style="color:#00009f">this</span><span class="token plain"> </span><span class="token operator" style="color:#393A34">!==</span><span class="token plain"> </span><span class="token string" style="color:#e3116c">"function"</span><span class="token punctuation" style="color:#393A34">)</span><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token keyword" style="color:#00009f">throw</span><span class="token plain"> </span><span class="token keyword" style="color:#00009f">new</span><span class="token plain"> </span><span class="token class-name">TypeError</span><span class="token punctuation" style="color:#393A34">(</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token string" style="color:#e3116c">"Function.prototype.bind was called on which is not a function"</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">)</span><span class="token punctuation" style="color:#393A34">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">}</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token keyword" style="color:#00009f">if</span><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">(</span><span class="token plain">thisArg </span><span class="token operator" style="color:#393A34">===</span><span class="token plain"> </span><span class="token keyword" style="color:#00009f">undefined</span><span class="token plain"> </span><span class="token operator" style="color:#393A34">||</span><span class="token plain"> thisArg </span><span class="token operator" style="color:#393A34">===</span><span class="token plain"> </span><span class="token keyword" style="color:#00009f">null</span><span class="token punctuation" style="color:#393A34">)</span><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> thisArg </span><span class="token operator" style="color:#393A34">=</span><span class="token plain"> window</span><span class="token punctuation" style="color:#393A34">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">}</span><span class="token plain"> </span><span class="token keyword" style="color:#00009f">else</span><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> thisArg </span><span class="token operator" style="color:#393A34">=</span><span class="token plain"> </span><span class="token function" style="color:#d73a49">Object</span><span class="token punctuation" style="color:#393A34">(</span><span class="token plain">thisArg</span><span class="token punctuation" style="color:#393A34">)</span><span class="token punctuation" style="color:#393A34">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">}</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token keyword" style="color:#00009f">const</span><span class="token plain"> func </span><span class="token operator" style="color:#393A34">=</span><span class="token plain"> </span><span class="token keyword" style="color:#00009f">this</span><span class="token punctuation" style="color:#393A34">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token keyword" style="color:#00009f">const</span><span class="token plain"> </span><span class="token function-variable function" style="color:#d73a49">bound</span><span class="token plain"> </span><span class="token operator" style="color:#393A34">=</span><span class="token plain"> </span><span class="token keyword" style="color:#00009f">function</span><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">(</span><span class="token parameter operator" style="color:#393A34">...</span><span class="token parameter">boundArgsArray</span><span class="token punctuation" style="color:#393A34">)</span><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token keyword" style="color:#00009f">let</span><span class="token plain"> isNew </span><span class="token operator" style="color:#393A34">=</span><span class="token plain"> </span><span class="token boolean" style="color:#36acaa">false</span><span class="token punctuation" style="color:#393A34">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token comment" style="color:#999988;font-style:italic">// 如果 func 不是构造器，直接使用 instanceof 将出错，所以需要用 try...catch 包裹</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token keyword" style="color:#00009f">try</span><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> isNew </span><span class="token operator" style="color:#393A34">=</span><span class="token plain"> </span><span class="token keyword" style="color:#00009f">this</span><span class="token plain"> </span><span class="token keyword" style="color:#00009f">instanceof</span><span class="token plain"> </span><span class="token class-name">func</span><span class="token punctuation" style="color:#393A34">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">}</span><span class="token plain"> </span><span class="token keyword" style="color:#00009f">catch</span><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">(</span><span class="token plain">error</span><span class="token punctuation" style="color:#393A34">)</span><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">{</span><span class="token punctuation" style="color:#393A34">}</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token keyword" style="color:#00009f">return</span><span class="token plain"> </span><span class="token function" style="color:#d73a49">func</span><span class="token punctuation" style="color:#393A34">.</span><span class="token function" style="color:#d73a49">apply</span><span class="token punctuation" style="color:#393A34">(</span><span class="token plain">isNew </span><span class="token operator" style="color:#393A34">?</span><span class="token plain"> </span><span class="token keyword" style="color:#00009f">this</span><span class="token plain"> </span><span class="token operator" style="color:#393A34">:</span><span class="token plain"> thisArg</span><span class="token punctuation" style="color:#393A34">,</span><span class="token plain"> argsArray</span><span class="token punctuation" style="color:#393A34">.</span><span class="token function" style="color:#d73a49">concat</span><span class="token punctuation" style="color:#393A34">(</span><span class="token plain">boundArgsArray</span><span class="token punctuation" style="color:#393A34">)</span><span class="token punctuation" style="color:#393A34">)</span><span class="token punctuation" style="color:#393A34">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">}</span><span class="token punctuation" style="color:#393A34">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token keyword" style="color:#00009f">const</span><span class="token plain"> </span><span class="token function-variable function" style="color:#d73a49">Empty</span><span class="token plain"> </span><span class="token operator" style="color:#393A34">=</span><span class="token plain"> </span><span class="token keyword" style="color:#00009f">function</span><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">(</span><span class="token punctuation" style="color:#393A34">)</span><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">{</span><span class="token punctuation" style="color:#393A34">}</span><span class="token punctuation" style="color:#393A34">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token class-name">Empty</span><span class="token punctuation" style="color:#393A34">.</span><span class="token plain">prototype </span><span class="token operator" style="color:#393A34">=</span><span class="token plain"> </span><span class="token keyword" style="color:#00009f">this</span><span class="token punctuation" style="color:#393A34">.</span><span class="token plain">prototype</span><span class="token punctuation" style="color:#393A34">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> bound</span><span class="token punctuation" style="color:#393A34">.</span><span class="token plain">prototype </span><span class="token operator" style="color:#393A34">=</span><span class="token plain"> </span><span class="token keyword" style="color:#00009f">new</span><span class="token plain"> </span><span class="token class-name">Empty</span><span class="token punctuation" style="color:#393A34">(</span><span class="token punctuation" style="color:#393A34">)</span><span class="token punctuation" style="color:#393A34">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token keyword" style="color:#00009f">return</span><span class="token plain"> bound</span><span class="token punctuation" style="color:#393A34">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"></span><span class="token punctuation" style="color:#393A34">}</span><span class="token punctuation" style="color:#393A34">;</span><br></span></code></pre><button type="button" aria-label="Copy code to clipboard" title="Copy" class="copyButton_eDfN clean-btn"><span class="copyButtonIcons_W9eQ" aria-hidden="true"><svg class="copyButtonIcon_XEyF" viewBox="0 0 24 24"><path d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg class="copyButtonSuccessIcon_i9w9" viewBox="0 0 24 24"><path d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div><h2 class="anchor anchorWithHideOnScrollNavbar_R0VQ" id="参考资料">参考资料<a class="hash-link" href="#参考资料" title="Direct link to heading"></a></h2><ol><li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function/apply" target="_blank" rel="noopener noreferrer">Function.prototype.apply()</a></li><li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function/call" target="_blank" rel="noopener noreferrer">Function.prototype.call()</a></li><li><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function/bind" target="_blank" rel="noopener noreferrer">Function.prototype.bind()</a></li></ol></div></article><nav class="pagination-nav docusaurus-mt-lg" aria-label="Docs pages navigation"><div class="pagination-nav__item"><a class="pagination-nav__link" href="/awesome-interview/book4/css-vertical-horizontal-center"><div class="pagination-nav__sublabel">Previous</div><div class="pagination-nav__label">样式：水平垂直居中方案</div></a></div><div class="pagination-nav__item pagination-nav__item--next"><a class="pagination-nav__link" href="/awesome-interview/book4/array-repeat-number"><div class="pagination-nav__sublabel">Next</div><div class="pagination-nav__label">算法：找到数组中重复的数字</div></a></div></nav></div></div><div class="col col--3"><div class="tableOfContents_cNA8 thin-scrollbar theme-doc-toc-desktop"><ul class="table-of-contents table-of-contents__left-border"><li><a href="#apply" class="table-of-contents__link toc-highlight">apply</a><ul><li><a href="#1-语法" class="table-of-contents__link toc-highlight">1. 语法</a></li><li><a href="#2-流程图" class="table-of-contents__link toc-highlight">2. 流程图</a></li><li><a href="#3-编写代码" class="table-of-contents__link toc-highlight">3. 编写代码</a></li></ul></li><li><a href="#call" class="table-of-contents__link toc-highlight">call</a><ul><li><a href="#1-语法-1" class="table-of-contents__link toc-highlight">1. 语法</a></li><li><a href="#2-流程图-1" class="table-of-contents__link toc-highlight">2. 流程图</a></li><li><a href="#3-编写代码-1" class="table-of-contents__link toc-highlight">3. 编写代码</a></li></ul></li><li><a href="#bind" class="table-of-contents__link toc-highlight">bind</a><ul><li><a href="#1-语法-2" class="table-of-contents__link toc-highlight">1. 语法</a></li><li><a href="#2-流程图-2" class="table-of-contents__link toc-highlight">2. 流程图</a></li><li><a href="#3-编写代码-2" class="table-of-contents__link toc-highlight">3. 编写代码</a></li></ul></li><li><a href="#参考资料" class="table-of-contents__link toc-highlight">参考资料</a></li></ul></div></div></div><div class="row"><div class="col"><div class="react-utterences"><div>Loading script...</div></div></div><div class="col col--3"></div></div></div></main></div></div></div>
|
||
<script src="/awesome-interview/assets/js/runtime~main.16895322.js"></script>
|
||
<script src="/awesome-interview/assets/js/main.a6349f88.js"></script>
|
||
</body>
|
||
</html> |