---
title: Map.prototype.keys()
slug: Web/JavaScript/Reference/Global_Objects/Map/keys
translation_of: Web/JavaScript/Reference/Global_Objects/Map/keys
---
<div>{{JSRef}}</div>

<div>O método <code><strong>keys()</strong></code> retorna um novo objeto do tipo <code><strong>Iterator</strong></code> que contem uma chave para cada elemento dentro do objeto <code>Map </code>na ordem que foram inseridos.</div>

<p> </p>

<h2 id="Sintaxe">Sintaxe</h2>

<pre class="syntaxbox"><code><em>myMap</em>.keys()</code></pre>

<h3 id="Tipo_de_Retorno">Tipo de Retorno</h3>

<p>Um novo objeto {{jsxref("Map")}}.</p>

<h2 id="Exemplos">Exemplos</h2>

<h3 id="Usando_keys()">Usando <code>keys()</code></h3>

<pre class="brush:js">var myMap = new Map();
myMap.set("0", "foo");
myMap.set(1, "bar");
myMap.set({}, "baz");

var mapIter = myMap.keys();

console.log(mapIter.next().value); // "0"
console.log(mapIter.next().value); // 1
console.log(mapIter.next().value); // Object
</pre>

<h2 id="Especificações">Especificações</h2>

<table class="standard-table">
 <tbody>
  <tr>
   <th scope="col">Specification</th>
   <th scope="col">Status</th>
   <th scope="col">Comment</th>
  </tr>
  <tr>
   <td>{{SpecName('ES6', '#sec-map.prototype.keys', 'Map.prototype.keys')}}</td>
   <td>{{Spec2('ES6')}}</td>
   <td>Definição inicial.</td>
  </tr>
  <tr>
   <td>{{SpecName('ESDraft', '#sec-map.prototype.keys', 'Map.prototype.keys')}}</td>
   <td>{{Spec2('ESDraft')}}</td>
   <td> </td>
  </tr>
 </tbody>
</table>

<h2 id="Compatibilidade_com_navegadores">Compatibilidade com navegadores</h2>

<p>{{CompatibilityTable}}</p>

<div id="compat-desktop">
<table class="compat-table">
 <tbody>
  <tr>
   <th>Feature</th>
   <th>Chrome</th>
   <th>Firefox (Gecko)</th>
   <th>Internet Explorer</th>
   <th>Opera</th>
   <th>Safari</th>
  </tr>
  <tr>
   <td>Basic support</td>
   <td>38</td>
   <td>{{CompatGeckoDesktop("20")}}</td>
   <td>{{CompatNo}}</td>
   <td>25</td>
   <td>7.1</td>
  </tr>
 </tbody>
</table>
</div>

<div id="compat-mobile">
<table class="compat-table">
 <tbody>
  <tr>
   <th>Feature</th>
   <th>Android</th>
   <th>Chrome for Android</th>
   <th>Firefox Mobile (Gecko)</th>
   <th>IE Mobile</th>
   <th>Opera Mobile</th>
   <th>Safari Mobile</th>
  </tr>
  <tr>
   <td>Basic support</td>
   <td>{{CompatNo}}</td>
   <td>38</td>
   <td>{{CompatGeckoMobile("20") }}</td>
   <td>{{CompatNo}}</td>
   <td>{{CompatNo}}</td>
   <td>8</td>
  </tr>
 </tbody>
</table>
</div>

<h2 id="Veja_também">Veja também</h2>

<ul>
 <li>{{jsxref("Map.prototype.entries()")}}</li>
 <li>{{jsxref("Map.prototype.values()")}}</li>
</ul>