commas)
    7. [ Deprecated features ](/en-US/docs/Web/JavaScript/Reference/Deprecated_and_obsolete_features)

##  In this article

  * Try it 
  * Syntax 
  * Description 
  * Examples 
  * Specifications 
  * Browser compatibility 
  * See also 

#  Exponentiation assignment (**=)

The **exponentiation assignment (` **= ` ) ** operator performs [
exponentiation ](/en-
US/docs/Web/JavaScript/Reference/Operators/Exponentiation) on the two operands
and assigns the result to the left operand.

##  Try it

##  Syntax

js

    
    
    x **= y
    

##  Description

` x **= y ` is equivalent to ` x = x ** y ` , except that the expression ` x `
is only evaluated once.

##  Examples

###  Using exponentiation assignment

js

    
    
    let bar = 5;
    
    bar **= 2; // 25
    bar **= "foo"; // NaN
    
    let foo = 3n;
    foo **= 2n; // 9n
    

##  Specifications

Specification  
---  
[ ECMAScript Language Specification  
#  sec-assignment-operators  ](https://tc39.es/ecma262/multipage/ecmascript-
language-expressions.html#sec-assignment-operators)  
  
##  Browser compatibility

BCD tables only load in the browser  with JavaScript enabled. Enable
JavaScript to view data.

##  See also

  * [ Assignment operators in the JS guide ](/en-US/docs/Web/JavaScript/Guide/Expressions_and_operators#assignment_operators)
  * [ Exponentiation ( ` ** ` ) ](/en-US/docs/Web/JavaScript/Reference/Operators/Exponentiation)

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