JavaScript Map.groupBy() 方法

课程表

JS 参考手册

JavaScript

Window

HTML DOM

Web API

HTML Obhekyto

</a></li> <li><a href="/tl/jsref/dom_obj_time.html" title="HTML DOM Time Obheto"><time></a></li> <li><a href="/tl/jsref/dom_obj_title.html" title="HTML DOM Title Obheto"><title></a></li> <li><a href="/tl/jsref/dom_obj_track.html" title="HTML DOM Track Obheto"><track></a></li> <li><a href="/tl/jsref/dom_obj_u.html" title="HTML DOM Underline Obheto"><u></a></li> <li><a href="/tl/jsref/dom_obj_ul.html" title="HTML DOM Ul Obheto"><ul></a></li> <li><a href="/tl/jsref/dom_obj_var.html" title="HTML DOM Variable Obheto"><var></a></li> <li><a href="/tl/jsref/dom_obj_video.html" title="HTML DOM Video Obheto"><video></a></li> </ul> <h2>其他参考手册</h2> <ul> <li><a href="/tl/jsref/obj_cssstyledeclaration.html" title="CSSStyleDeclaration Obheto">CSSStyleDeclaration</a></li> <li><a href="/tl/jsref/jsref_type_conversion.html" title="JavaScript 类型转换">JS 类型转换</a></li> </ul> </div> <div><h3><center> 选修课 </center><h3> <h2>课程推荐：</h2> <ul> <li><a href="/tl/howto/index.html" title="CodeW3C.com 百宝箱">CodeW3C.com 百宝箱</a></li> </ul> </div> </div> <div id="maincontent"> <div class="idea"> <a href="/"><button>English</button></a> <a href="/zh/"><button>中文</button></a> <a href="/oldzh/"><button>繁體中文</button></a> <a href="/ru/"><button>Русский</button></a> <a href="/fr/"><button>Français</button></a> <a href="/de/"><button>Deutsch</button></a> <a href="/es/"><button>Español</button></a> <a href="/pt/"><button>Português</button></a> <a href="/ja/"><button>日本語</button></a> <a href="/ko/"><button>한국어</button></a> <a href="/it/"><button>Italiano</button></a> <a href="/ar/"><button>عربي</button></a> <a href="/hi/"><button>हिंदी</button></a> <a href="/bn/"><button>বাংলা</button></a> <a href="/ms/"><button>Bahasa Malaysia</button></a> <a href="/my/"><button>မြန်မာ</button></a> <a href="/vi/"><button>Tiếng Việt</button></a> <a href="/th/"><button>ภาษาไทย</button></a> <a href="/lo/"><button>ລາວ</button></a> <a href="/id/"><button>Bahasa Indonesia</button></a> <a href="/ur/"><button>اردو</button></a> <a href="/ha/"><button>Hausa</button></a> <a href="/pl/"><button>Język polski</button></a> <a href="/pa/"><button>ਪੰਜਾਬੀ</button></a> <a href="/sv/"><button>Svenska</button></a> <a href="/da/"><button>Dansk</button></a> <a href="/nl/"><button>Nederlands</button></a> <a href="/tr/"><button>Türkçe</button></a> <a href="/fi/"><button>suom.</button></a> <a href="/el/"><button>Ελληνικά</button></a> <a href="/fa/"><button>فارسی</button></a> <a href="/sw/"><button>Kiswahili</button></a> <a href="/te/"><button>తెలుగు</button></a> <a href="/tl/"><button>wikang Galu</button></a> </div> <h1>JavaScript Map.groupBy()</h1> <div class="prenextnav-ref"> <ul> <li> 上一页 <a href="/tl/jsref/jsref_map_get.html" title="JavaScript Map get() 方法">get()</a></li> <li> 下一页 <a href="/tl/jsref/jsref_map_has.html" title="JavaScript Map has() 方法">has()</a></li> <li> 返回上一层 <a href="/tl/jsref/jsref_obj_map.html" title="Manwal ng Reference ng JavaScript Map">Manwal ng Reference ng JavaScript Map</a></li> </ul> </div> <section> <h2>定义和用法</h2> <p><code>Map.groupBy()</code> 方法根据回调函数返回的字符串值对对象的元素进行分组。</p> <p><code>Map.groupBy()</code> 方法不会改变原始对象。</p> </section> <section> <h2>实例</h2> <pre class="language-js"> // 创建一个数组 const fruits = [ {name:"apples", quantity:300}, {name:"bananas", quantity:500}, {name:"oranges", quantity:200}, {name:"kiwi", quantity:150} // Function na gagamitin para sa paggrupong elemento function myCallback({ quantity }) { return quantity > 200 ? "ok" : "low"; } // Paggrupong ayon sa dami const result = Map.groupBy(fruits, myCallback); </pre> <p class="tiy"><a target="_blank" href="/tl/tiy/t.html?f=jsref_map_groupby">Subukan nang personal</a></p> </section> <section class="note"> <h2>Babala</h2> <p>Ang mga elemento sa orihinal na object at sa ibinabalik na object ay magkapareho.</p> <p>Ang pagbabago sa anumang object ay makikita sa ibang object.</p> </section> <section> <h2>Ang pagkakaiba ng Object.groupBy() at Map.groupBy()</h2> <p><code>Object.groupBy()</code> at <code>Map.groupBy()</code> ang pagkakaiba nito ay:</p> <p><code>Object.groupBy()</code> I-group ang mga elemento sa isang JavaScript object.</p> <p><code>Map.groupBy()</code> I-group ang mga elemento sa isang Map object.</p> </section> <section> <h2>pahayag</h2> <pre class="language-js"> Map.groupBy(<i>iterable</i>, <i>callback</i>) </pre> <h3>parameter</h3> <table class="parameter"> <tr> <th style="width: 25%;">parameter</th> <th>paglalarawan</th> </tr> <tr> <td><i>iterable</i></td> <td>Mandahil. Isang maaari mapasukan na array o Map.</td> </tr> <tr> <td><i>callback</i></td> <td> <p>Mandahil. Ang function na gagawin para sa bawat elemento.</p> <p>Ang function na ito ay dapat ibalik ang pangalan ng grupo ng elemento.</p> </td> </tr> </table> <h3>baling sabihin</h3> <table class="technical-details"> <tr> <th style="width: 25%;">uri</th> <th>paglalarawan</th> </tr> <tr> <td>Object</td> <td>kasama ang Map na may elementong panggrupong elemento.</td> </tr> </table> </section> <section> <h2>sumusuporta ng browser</h2> <p><code>Map.groupBy()</code> ay katangian ng ES2024.</p> <p>mula 2024 Marso, lahat ng modernong browser ay ganap na sumusuporta sa:</p> <table class="browser-support"> <tr> <th class="bsChrome">Chrome</th> <th class="bsEdge">Edge</th> <th class="bsFirefox">Firefox</th> <th class="bsSafari">Safari</th> <th class="bsOpera">Opera</th> </tr> <tr> <td>Chrome 117</td> <td>Edge 117</td> <td>Firefox 119</td> <td>Safari 17.4</td> <td>Opera 103</td> </tr> <tr> <td>2023 年 9 月</td> <td>2023 年 9 月</td> <td>2023 年 10 月</td> <td>2024 年 10 月</td> <td>2023 年 5 月</td> </tr> </table> </section> <div class="prenextnav-ref"> <ul> <li> 上一页 <a href="/tl/jsref/jsref_map_get.html" title="JavaScript Map get() 方法">get()</a></li> <li> 下一页 <a href="/tl/jsref/jsref_map_has.html" title="JavaScript Map has() 方法">has()</a></li> <li> 返回上一层 <a href="/tl/jsref/jsref_obj_map.html" title="Manwal ng Reference ng JavaScript Map">Manwal ng Reference ng JavaScript Map</a></li> </ul> </div><div style="background-color:#fcfdf8; padding:0;"> </div> </div>  <div id="sidebar"> <div><h3><center> 工具箱 </center><h3> <h5 id="tools_reference"><a href="/tl/jsref/index.html">Manwal ng Reference ng JavaScript at HTML DOM</a></h5> <h5 id="tools_example"><a href="/tl/js/js_examples.html">JavaScript 实例</a></h5> <h5 id="tools_quiz"><a href="/tl/js/js_quiz.html">JavaScript 测验</a></h5> <h5 id="tools_tutorial"><a href="/tl/js/index.html">JavaScript 教程</a></h5> </div> <div><h3><center> 赞助商链接 </center><h3> <div id="sbtg"> <script src="/myjs/zzsr.js"></script> </div> </div> </div> <div id="footer"> <p id="p1"> CodeW3C.com 提供的内容仅用于培训和测试，不保证内容的正确性。通过使用本站内容随之而来的风险与本站无关。版权所有，保留一切权利。 </p> <p id="p2"> <a href="/tl/about/index.html" title="关于 CodeW3C.com">关于 CodeW3C.com</a> <a href="/tl/about/about_helping.html" title="帮助 CodeW3C.com">帮助 CodeW3C.com</a> <a href="/tl/about/about_use.html" title="关于使用">使用条款</a> <a href="/tl/about/about_privacy.html" title="关于隐私">隐私条款</a> <a href="http://www.comfortsoftwaregroup.com/" target="_blank"><img src="/comfortsoftwaregroup.png"></a> <a href="http://www.ce4e.com/" target="_blank"><img src="/poweredby.png" alt="Pangangasiwa ng Ce4e.com"></a> </p> </div> </div>  <script src="/myjs/tongji.js"></script> </body> </html>