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+---
+title: Symbol.hasInstance
+slug: Web/JavaScript/Reference/Global_Objects/Symbol/hasInstance
+tags:
+  - Propriedade
+  - Referencia
+translation_of: Web/JavaScript/Reference/Global_Objects/Symbol/hasInstance
+---
+<div>{{JSRef}}</div>
+
+<p>O symbol bem-conhecido <strong><code>Symbol.hasInstance</code></strong> é usado para determinar se um objecto construtor reconhece um objecto como de sua instância. O comportamento do operador {{jsxref("Operators/instanceof", "instanceof")}} pode ser customizado por este symbol.</p>
+
+<div>{{js_property_attributes(0,0,0)}}</div>
+
+<h2 id="Exemplos">Exemplos</h2>
+
+<p>Tu podes implementar o comportamento customizado do seu <code>instanceof</code> deste jeito; por exemplo:</p>
+
+<pre class="brush: js">class MyArray {
+  static [Symbol.hasInstance](instance) {
+    return this.prototype.isPrototypeOf(instance) ||
+           Array.isArray(instance);
+  }
+}
+
+console.log([] instanceof MyArray); // true
+console.log(new MyArray instanceof MyArray); // true
+console.log(new Image instanceof MyArray); // false
+
+class MySubArray extends MyArray {}
+console.log(new MySubArray instanceof MySubArray); // true
+console.log(new MySubArray instanceof MyArray); // true
+console.log(new MyArray instanceof MySubArray); // false</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-symbol.hasinstance', 'Symbol.hasInstance')}}</td>
+   <td>{{Spec2('ES6')}}</td>
+   <td>Initial definition.</td>
+  </tr>
+  <tr>
+   <td>{{SpecName('ESDraft', '#sec-symbol.hasinstance', 'Symbol.hasInstance')}}</td>
+   <td>{{Spec2('ESDraft')}}</td>
+   <td> </td>
+  </tr>
+ </tbody>
+</table>
+
+<h2 id="Compatibilidade_com_os_navegadores">Compatibilidade com os 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>{{CompatChrome(51)}}</td>
+   <td>{{ CompatGeckoDesktop(50) }}</td>
+   <td>{{CompatNo}}</td>
+   <td>{{CompatUnknown}}</td>
+   <td>{{CompatUnknown}}</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>{{CompatUnknown}}</td>
+   <td>{{CompatUnknown}}</td>
+   <td>{{ CompatGeckoMobile(50) }}</td>
+   <td>{{CompatNo}}</td>
+   <td>{{CompatUnknown}}</td>
+   <td>{{CompatUnknown}}</td>
+  </tr>
+ </tbody>
+</table>
+</div>
+
+<h2 id="Veja_também">Veja também</h2>
+
+<ul>
+ <li>{{jsxref("Operators/instanceof", "instanceof")}}</li>
+ <li>{{jsxref("Global_Objects/Object/isPrototypeOf", "isPrototypeOf()")}}</li>
+</ul>