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Exponentiation (**)

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.

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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.

For example, -2 ** 2 is 4 in Bash, but is -4 in other languages (such as Python). This is invalid in JavaScript, as the operation is ambiguous. You have to parenthesize either side — for example, as -(2 ** 2) — to make the intention 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

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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https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Exponentiation