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<!DOCTYPE html>  <html lang="en"> <head> <meta charset="utf-8"> <title>CanJS - id</title> <meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1, user-scalable=no"> <link rel="stylesheet" type="text/css" href="./static/bundles/bit-docs-site/static.css"> <link rel="shortcut icon" sizes="16x16 24x24 32x32 48x48 64x64" href="/docs/images/canjs_favicon.ico"> <link rel="apple-touch-icon" sizes="57x57" href="../docs/images/canjs_favicon_57x57.png"> <link rel="apple-touch-icon-precomposed" sizes="57x57" href="../docs/images/canjs_favicon_57x57.png"> <link rel="apple-touch-icon" sizes="72x72" href="../docs/images/canjs_favicon_72x72.png"> <link rel="apple-touch-icon" sizes="114x114" href="../docs/images/canjs_favicon_114x114.png"> <link rel="apple-touch-icon" sizes="120x120" href="../docs/images/canjs_favicon_128x128.png"> <link rel="apple-touch-icon" sizes="144x144" href="../docs/images/canjs_favicon_144x144.png"> <link rel="apple-touch-icon" sizes="152x152" href="../docs/images/canjs_favicon_152x152.png"> <meta content="yes" name="apple-mobile-web-app-capable"> <meta name="apple-mobile-web-app-status-bar-style" content="white-translucent"> <script> (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){ (i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o), m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m) })(window,document,'script','https://www.google-analytics.com/analytics.js','ga'); ga('create', 'UA-2302003-11', 'auto'); ga('send', 'pageview'); </script> </head> <body> <input type="checkbox" id="nav-trigger" class="nav-trigger"/> <label for="nav-trigger">Menu</label> <div id="everything"> <div id="left" class="column"> <div class="top-left"> <div class="brand"> <div class="logo"> <a href="../index.html" alt="CanJS"></a> <div class="dropdown project-dropdown"> <a href="https://donejs.com/">DoneJS</a> <a href="http://stealjs.com/">StealJS</a> <a href="http://jquerypp.com/">jQuery ++</a> <a href="https://funcunit.com/">FuncUnit</a> <a href="http://documentjs.com/">DocumentJS</a> </div> </div> <div class="version"> <div class="version-number"> 3.0.0 </div> <div class="dropdown version-dropdown"> <a href="https://v2.canjs.com">2.3.27</a> </div> </div> </div> <div class="search-bar"> <p>   </p> </div> </div> <div class="bottom-left"> <div class="social-side-container"> <ul class="social-side"> <li> <a class="header-mobile github" href="https://github.com/canjs/canjs" target="_blank"><img class="social-icon-small" src="../docs/images/github.png">Github</a> </li> <li> <a class="header-mobile twitter" href="https://twitter.com/canjs" target="_blank"><img class="social-icon-small" src="../docs/images/twitter.png">Twitter</a> </li> </ul> <ul class="social-side"> <li> <a class="header-mobile" href="https://gitter.im/canjs/canjs" target="_blank">Chat</a> </li> <li> <a class="header-mobile" href="http://forums.donejs.com/c/canjs" target="_blank">Forum</a> </li> </ul> </div> <ul> <li class=" "> <a class="page" href="guides.html" title="Welcome to CanJS! 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This is the default sorted property if no <a href="can-set.props.sort.html" title="Defines the sortable property and behavior.">sort</a> is provided.</p> <pre><code class="language-js">var algebra = new set.Algebra(set.props.id("_id")); algebra.index( {sortBy: "name desc"}, [{name: "Meyer"}], {name: "Adams"}) //-> 1 algebra.index( {sortBy: "name"}, [{name: "Meyer"}], {name: "Adams"}) //-> 0 </code></pre> <div class="parameters"> <h3 class="parameters-title">Parameters</h3> <ol> <li><b>prop</b> <code>{String}</code>: <p>The property name that defines the unique property id.</p> </li> </ol> </div> <div class="returns"> <h3 class="returns-title">Returns</h3> <p> <code>{<a href="can-set.compares.html" title="An object of property names and prop functions. { // return `true` if the values should be considered the same: lastName: function(aValue, bValue){ return (""+aValue).toLowerCase() === (""+bValue).toLowerCase(); } }">Compares</a>}</code>: <p>Returns a compares that can be used to create a <code>set.Algebra</code>.</p> </p> </div> </div> <script type="text/javascript"> var docObject = {"type":"function","name":"can-set.props.id","parent":"can-set.props","src":{"line":341,"codeLine":370,"path":"node_modules/can-set/src/props.js"},"description":"Defines the identify property. \n","title":"id","signatures":[{"code":"set.props.id(prop)","description":"\n\nDefines the property name on items that uniquely\nidentifies them. This is the default sorted property if no\n[can-set.props.sort] is provided.\n\n```js\nvar algebra = new set.Algebra(set.props.id(\"_id\"));\nalgebra.index(\n {sortBy: \"name desc\"},\n [{name: \"Meyer\"}],\n {name: \"Adams\"}) //-> 1\n\nalgebra.index(\n {sortBy: \"name\"},\n [{name: \"Meyer\"}],\n {name: \"Adams\"}) //-> 0\n```\n","params":[{"types":[{"type":"String"}],"name":"prop","description":"The property name that defines the unique property id."}],"returns":{"types":[{"type":"can-set.compares"}],"description":"Returns a compares that can be used to create\na `set.Algebra`.\n "}}],"_curParam":{"types":[{"type":"String"}],"name":"prop","description":"The property name that defines the unique property id."},"_curReturn":{"types":[{"type":"can-set.compares"}],"description":"Returns a compares that can be used to create\na `set.Algebra`.\n "},"pathToRoot":".."}; </script> </article> <footer><p>CanJS is part of <a href="http://donejs.com" target="_blank">DoneJS</a>. 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