mirror of
https://github.com/foomo/foomo-docs.git
synced 2025-10-16 12:35:40 +00:00
22 lines
18 KiB
HTML
22 lines
18 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-frontend/performance">
|
||
<head>
|
||
<meta charset="UTF-8">
|
||
<meta name="generator" content="Docusaurus v2.4.0">
|
||
<title data-rh="true">Performance | foomo project docs</title><meta data-rh="true" name="viewport" content="width=device-width,initial-scale=1"><meta data-rh="true" name="twitter:card" content="summary_large_image"><meta data-rh="true" property="og:url" content="https://www.foomo.org/docs/frontend/performance"><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="Performance | foomo project docs"><meta data-rh="true" name="description" content="JS"><meta data-rh="true" property="og:description" content="JS"><link data-rh="true" rel="icon" href="/img/favicon.ico"><link data-rh="true" rel="canonical" href="https://www.foomo.org/docs/frontend/performance"><link data-rh="true" rel="alternate" href="https://www.foomo.org/docs/frontend/performance" hreflang="en"><link data-rh="true" rel="alternate" href="https://www.foomo.org/docs/frontend/performance" hreflang="x-default"><link data-rh="true" rel="preconnect" href="https://SUATUVZDDM-dsn.algolia.net" crossorigin="anonymous"><link rel="alternate" type="application/rss+xml" href="/blog/rss.xml" title="foomo project docs RSS Feed">
|
||
<link rel="alternate" type="application/atom+xml" href="/blog/atom.xml" title="foomo project docs Atom Feed">
|
||
|
||
|
||
|
||
<link rel="search" type="application/opensearchdescription+xml" title="foomo project docs" href="/opensearch.xml"><link rel="stylesheet" href="/assets/css/styles.45fe17b6.css">
|
||
<link rel="preload" href="/assets/js/runtime~main.339c949d.js" as="script">
|
||
<link rel="preload" href="/assets/js/main.4cf1833b.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=new URLSearchParams(window.location.search).get("docusaurus-theme")}catch(t){}return t}()||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" aria-label="Skip to main content"><a class="skipToContent_fXgn" href="#docusaurus_skipToContent_fallback">Skip to main content</a></div><nav aria-label="Main" class="navbar navbar--fixed-top"><div class="navbar__inner"><div class="navbar__items"><button aria-label="Toggle navigation bar" aria-expanded="false" class="navbar__toggle clean-btn" type="button"><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="/"><b class="navbar__title text--truncate">foomo</b></a><a class="navbar__item navbar__link" href="/docs/general">General</a><a aria-current="page" class="navbar__item navbar__link navbar__link--active" href="/docs/frontend">Frontend</a><a class="navbar__item navbar__link" href="/docs/backend">Backend</a><a class="navbar__item navbar__link" href="/docs/devops">DevOps</a><a class="navbar__item navbar__link" href="/docs/projects">Projects</a></div><div class="navbar__items navbar__items--right"><a class="navbar__item navbar__link" href="/blog">Blog</a><div class="searchBox_ZlJk"><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 id="docusaurus_skipToContent_fallback" class="main-wrapper mainWrapper_z2l0 docsWrapper_BCFX"><button aria-label="Scroll back to top" class="clean-btn theme-back-to-top-button backToTopButton_sjWU" type="button"></button><div class="docPage__5DB"><aside class="theme-doc-sidebar-container docSidebarContainer_b6E3"><div class="sidebarViewport_Xe31"><div class="sidebar_njMd"><nav aria-label="Docs sidebar" class="menu thin-scrollbar menu_SIkG"><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="/docs/frontend">Frontend Guide</a></li><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-1 menu__list-item"><a class="menu__link" href="/docs/frontend/css">CSS</a></li><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-1 menu__list-item"><a class="menu__link" href="/docs/frontend/rtfm">RTFM</a></li><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-1 menu__list-item"><a class="menu__link" href="/docs/frontend/setup">Setup</a></li><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-1 menu__list-item"><a class="menu__link" href="/docs/frontend/stack">Stack</a></li><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-1 menu__list-item"><a class="menu__link menu__link--active" aria-current="page" href="/docs/frontend/performance">Performance</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="/docs/frontend/typescript/objects">TypeScript</a></div></li><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-1 menu__list-item"><a class="menu__link" href="/docs/frontend/debugging_js">Debugging in JavaScript</a></li><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-1 menu__list-item"><a class="menu__link" href="/docs/frontend/pitfalls">Pittfals</a></li><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-1 menu__list-item"><a class="menu__link" href="/docs/frontend/vscode">vscode</a></li></ul></nav></div></div></aside><main class="docMainContainer_gTbr"><div class="container padding-top--md padding-bottom--lg"><div class="row"><div class="col docItemCol_VOVn"><div class="docItemContainer_Djhp"><article><nav class="theme-doc-breadcrumbs breadcrumbsContainer_Z_bl" aria-label="Breadcrumbs"><ul class="breadcrumbs" itemscope="" itemtype="https://schema.org/BreadcrumbList"><li class="breadcrumbs__item"><a aria-label="Home page" class="breadcrumbs__link" href="/"><svg viewBox="0 0 24 24" class="breadcrumbHomeIcon_YNFT"><path d="M10 19v-5h4v5c0 .55.45 1 1 1h3c.55 0 1-.45 1-1v-7h1.7c.46 0 .68-.57.33-.87L12.67 3.6c-.38-.34-.96-.34-1.34 0l-8.36 7.53c-.34.3-.13.87.33.87H5v7c0 .55.45 1 1 1h3c.55 0 1-.45 1-1z" fill="currentColor"></path></svg></a></li><li itemscope="" itemprop="itemListElement" itemtype="https://schema.org/ListItem" class="breadcrumbs__item breadcrumbs__item--active"><span class="breadcrumbs__link" itemprop="name">Performance</span><meta itemprop="position" content="1"></li></ul></nav><div class="tocCollapsible_ETCw theme-doc-toc-mobile tocMobile_ITEo"><button type="button" class="clean-btn tocCollapsibleButton_TO0P">On this page</button></div><div class="theme-doc-markdown markdown"><h1>Performance</h1><h2 class="anchor anchorWithStickyNavbar_LWe7" id="js">JS<a href="#js" class="hash-link" aria-label="Direct link to JS" title="Direct link to JS"></a></h2><p>JS is nowadays extremely fast and yet we have many performance issues. Here you can find few common mistakes that occur in JS that can decrease performance.</p><h3 class="anchor anchorWithStickyNavbar_LWe7" id="extensive-use-of-map-filter">Extensive use of .map, .filter<a href="#extensive-use-of-map-filter" class="hash-link" aria-label="Direct link to Extensive use of .map, .filter" title="Direct link to Extensive use of .map, .filter"></a></h3><p>Let's say you have a large list of objects and you would like to filter them and transform them in some form. Usually we do this:</p><div class="language-js codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#bfc7d5;--prism-background-color:#292d3e"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-js codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#bfc7d5"><span class="token keyword" style="font-style:italic">const</span><span class="token plain"> largeArray </span><span class="token operator" style="color:rgb(137, 221, 255)">=</span><span class="token plain"> </span><span class="token punctuation" style="color:rgb(199, 146, 234)">[</span><span class="token plain"> </span><span class="token spread operator" style="color:rgb(137, 221, 255)">...</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token plain"> </span><span class="token punctuation" style="color:rgb(199, 146, 234)">]</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">largeArray</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token method function property-access" style="color:rgb(130, 170, 255)">map</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token parameter">obj</span><span class="token plain"> </span><span class="token arrow operator" style="color:rgb(137, 221, 255)">=></span><span class="token plain"> </span><span class="token function" style="color:rgb(130, 170, 255)">transformObj</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token plain">obj</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token method function property-access" style="color:rgb(130, 170, 255)">filter</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token plain">omitBadObject</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg class="copyButtonIcon_y97N" 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_LjdS" 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></div><p>In the above case we first loop through whole set, transform it and then filter things out. Not only does this goes through all the items twice, but it also first time goes through all the items and then filters them.
|
||
One optimization would be to first filter them and then transform them, but ideally we should just use a normal for loop or forEach where you go through items only once.</p><div class="language-js codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#bfc7d5;--prism-background-color:#292d3e"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-js codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#bfc7d5"><span class="token keyword" style="font-style:italic">const</span><span class="token plain"> finalArray </span><span class="token operator" style="color:rgb(137, 221, 255)">=</span><span class="token plain"> </span><span class="token punctuation" style="color:rgb(199, 146, 234)">[</span><span class="token punctuation" style="color:rgb(199, 146, 234)">]</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain">largeArray</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token method function property-access" style="color:rgb(130, 170, 255)">forEach</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token parameter">obj</span><span class="token plain"> </span><span class="token arrow operator" style="color:rgb(137, 221, 255)">=></span><span class="token plain"> </span><span class="token punctuation" style="color:rgb(199, 146, 234)">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> </span><span class="token keyword control-flow" style="font-style:italic">if</span><span class="token plain"> </span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token function" style="color:rgb(130, 170, 255)">omitBadObject</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token plain">obj</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"> </span><span class="token punctuation" style="color:rgb(199, 146, 234)">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> finalArray</span><span class="token punctuation" style="color:rgb(199, 146, 234)">.</span><span class="token method function property-access" style="color:rgb(130, 170, 255)">push</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token function" style="color:rgb(130, 170, 255)">transformObj</span><span class="token punctuation" style="color:rgb(199, 146, 234)">(</span><span class="token plain">obj</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"> </span><span class="token punctuation" style="color:rgb(199, 146, 234)">}</span><span class="token plain"></span><br></span><span class="token-line" style="color:#bfc7d5"><span class="token plain"></span><span class="token punctuation" style="color:rgb(199, 146, 234)">}</span><span class="token punctuation" style="color:rgb(199, 146, 234)">)</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg class="copyButtonIcon_y97N" 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_LjdS" 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></div><p>This code will skip another loop of items.</p></div><footer class="theme-doc-footer docusaurus-mt-lg"><div class="theme-doc-footer-edit-meta-row row"><div class="col"><a href="https://github.com/foomo/foomo-docs/tree/main/foomo/docs/frontend/performance.md" target="_blank" rel="noreferrer noopener" class="theme-edit-this-page"><svg fill="currentColor" height="20" width="20" viewBox="0 0 40 40" class="iconEdit_Z9Sw" aria-hidden="true"><g><path d="m34.5 11.7l-3 3.1-6.3-6.3 3.1-3q0.5-0.5 1.2-0.5t1.1 0.5l3.9 3.9q0.5 0.4 0.5 1.1t-0.5 1.2z m-29.5 17.1l18.4-18.5 6.3 6.3-18.4 18.4h-6.3v-6.2z"></path></g></svg>Edit this page</a></div><div class="col lastUpdated_vwxv"></div></div></footer></article><nav class="pagination-nav docusaurus-mt-lg" aria-label="Docs pages navigation"><a class="pagination-nav__link pagination-nav__link--prev" href="/docs/frontend/stack"><div class="pagination-nav__sublabel">Previous</div><div class="pagination-nav__label">Stack</div></a><a class="pagination-nav__link pagination-nav__link--next" href="/docs/frontend/typescript/objects"><div class="pagination-nav__sublabel">Next</div><div class="pagination-nav__label">Objects</div></a></nav></div></div><div class="col col--3"><div class="tableOfContents_bqdL thin-scrollbar theme-doc-toc-desktop"><ul class="table-of-contents table-of-contents__left-border"><li><a href="#js" class="table-of-contents__link toc-highlight">JS</a><ul><li><a href="#extensive-use-of-map-filter" class="table-of-contents__link toc-highlight">Extensive use of .map, .filter</a></li></ul></li></ul></div></div></div></div></main></div></div><footer class="footer"><div class="container container-fluid"><div class="row footer__links"><div class="col footer__col"><div class="footer__title">github</div><ul class="footer__items clean-list"><li class="footer__item"><a href="https://github.com/foomo" target="_blank" rel="noopener noreferrer" class="footer__link-item">https://github.com/foomo</a></li></ul></div><div class="col footer__col"><div class="footer__title">legal</div><ul class="footer__items clean-list"><li class="footer__item"><a class="footer__link-item" href="/etc/imprint">Imprint</a></li></ul></div></div><div class="footer__bottom text--center"><div class="footer__copyright">© 2023 bestbytes</div></div></div></footer></div>
|
||
<script src="/assets/js/runtime~main.339c949d.js"></script>
|
||
<script src="/assets/js/main.4cf1833b.js"></script>
|
||
</body>
|
||
</html> |