The exponentiation operator (**
) returns the result of raising the first operand to the power of the second operand. It is equivalent to Math.pow
, except it also accepts BigInts as operands.
Exponentiation (**)
Try it
Syntax
x ** y
Description
The exponentiation operator is right-associative: a ** b ** c
is equal to a ** (b ** c)
.
In most languages, such as PHP, Python, and others that have an exponentiation operator (**
), the exponentiation operator is defined to have a higher precedence than unary operators, such as unary +
and unary -
, but there are a few exceptions. For example, in Bash, the **
operator is defined to have a lower precedence than unary operators.
In JavaScript, it is impossible to write an ambiguous exponentiation expression. That is, you cannot put a unary operator (+/-/~/!/delete/void/typeof
) immediately before the base number; doing so will cause a SyntaxError.
-2 ** 2; // 4 in Bash, -4 in other languages. // This is invalid in JavaScript, as the operation is ambiguous. -(2 ** 2); // -4 in JavaScript and the author's intention is unambiguous.
Note that some programming languages use the caret symbol ^ for exponentiation, but JavaScript uses that symbol for the bitwise logical XOR operator.
Examples
Basic exponentiation
2 ** 3 // 8 3 ** 2 // 9 3 ** 2.5 // 15.588457268119896 10 ** -1 // 0.1 NaN ** 2 // NaN
Associativity
2 ** 3 ** 2 // 512 2 ** (3 ** 2) // 512 (2 ** 3) ** 2 // 64
Usage with unary operators
To invert the sign of the result of an exponentiation expression:
-(2 ** 2) // -4
To force the base of an exponentiation expression to be a negative number:
(-2) ** 2 // 4
Specifications
Specification |
---|
ECMAScript Language Specification # sec-exp-operator |
Browser compatibility
Desktop | Mobile | Server | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | WebView Android | Chrome Android | Firefox for Android | Opera Android | Safari on IOS | Samsung Internet | Deno | Node.js | |
Exponentiation |
52
|
14
|
52
|
No
|
39
|
10.1
|
51
|
52
|
52
|
41
|
10.3
|
6.0
|
1.0
|
7.0.0
6.5.0
|
See also
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Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Exponentiation