---
title: Exponentiation assignment (**=)
slug: Web/JavaScript/Reference/Operators/Exponentiation_assignment
translation_of: Web/JavaScript/Reference/Operators/Exponentiation_assignment
---
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<p>The exponentiation assignment operator (<code>**=</code>) raises the value of a variable to the power of the right operand.</p>

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<h2 id="语法">语法</h2>

<pre class="syntaxbox notranslate"><strong>Operator:</strong> x **= y
<strong>Meaning:</strong>  x  = x ** y</pre>

<h2 id="Examples">Examples</h2>

<h3 id="Using_exponentiation_assignment">Using exponentiation assignment</h3>

<pre class="brush: js notranslate">// Assuming the following variable
//  bar = 5

bar **= 2     // 25
bar **= 'foo' // NaN</pre>

<h2 id="Specifications">Specifications</h2>

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<h2 id="Browser_compatibility">Browser compatibility</h2>



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

<h2 id="See_also">See also</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/Exponentiation">Exponentiation operator</a></li>
</ul>

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