files/zh-cn/web/javascript/reference/operators/unsigned_right_shift_assignment/index.html


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---
title: Unsigned right shift assignment (>>>=)
slug: Web/JavaScript/Reference/Operators/Unsigned_right_shift_assignment
translation_of: Web/JavaScript/Reference/Operators/Unsigned_right_shift_assignment
---
<div>{{jsSidebar("Operators")}}</div>

<p>The unsigned right shift assignment operator (<em><code>&gt;&gt;&gt;=</code></em>) moves the specified amount of bits to the right and assigns the result to the variable.</p>

<div>{{EmbedInteractiveExample("pages/js/expressions-unsigned-right-shift-assignment.html")}}</div>


<h2 id="语法">语法</h2>

<pre class="syntaxbox"><strong>Operator:</strong> x &gt;&gt;&gt;= y
<strong>Meaning:</strong>  x    = x &gt;&gt;&gt; y</pre>

<h2 id="例子">例子</h2>

<h3 id="Using_unsigned_right_shift_assignment">Using unsigned right shift assignment</h3>

<pre class="brush: js">let a = 5; //   (00000000000000000000000000000101)
a &gt;&gt;&gt;= 2;  // 1 (00000000000000000000000000000001)

let b = -5; // (-00000000000000000000000000000101)
b &gt;&gt;&gt;= 2;   // 1073741822 (00111111111111111111111111111110)</pre>

<h2 id="规范">规范</h2>

<table class="standard-table">
 <tbody>
  <tr>
   <th scope="col">Specification</th>
  </tr>
  <tr>
   <td>{{SpecName('ESDraft', '#sec-assignment-operators', 'Assignment operators')}}</td>
  </tr>
 </tbody>
</table>

<h2 id="浏览器兼容性">浏览器兼容性</h2>


<p>{{Compat("javascript.operators.unsigned_right_shift_assignment")}}</p>

<h2 id="参见">参见</h2>

<ul>
 <li><a href="/en-US/docs/Web/JavaScript/Guide/Expressions_and_Operators#Assignment">Assignment operators in the JS guide</a></li>
 <li><a href="/en-US/docs/Web/JavaScript/Reference/Operators/Unsigned_right_shift">Unsigned right shift operator</a></li>
</ul>