/JavaScript

# 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.

## Syntax

```Operator: var1 ** var2
```

## 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
```

## Browser compatibilityUpdate compatibility data on GitHub

Desktop
Chrome Edge Firefox Internet Explorer Opera Safari
Exponentiation (`**`) 52 14 52 No 39 10.1
Mobile
Android webview Chrome for Android Firefox for Android Opera for Android Safari on iOS Samsung Internet
Exponentiation (`**`) 51 52 52 41 10.3 6.0
Server
Node.js
Exponentiation (`**`) 7.0.0
7.0.0
6.5.0
Disabled
Disabled From version 6.5.0: this feature is behind the `--harmony` runtime flag.