Math.pow() - JavaScript 编辑

The Math.pow() function returns the base to the exponent power, that is, baseexponent.

The source for this interactive example is stored in a GitHub repository. If you'd like to contribute to the interactive examples project, please clone https://github.com/mdn/interactive-examples and send us a pull request.

The source for this interactive example is stored in a GitHub repository. If you'd like to contribute to the interactive examples project, please clone https://github.com/mdn/interactive-examples and send us a pull request.

Syntax

Math.pow(base, exponent)

Parameters

base

The base number.

exponent

The exponent used to raise the base.

Return value

A number representing the given base taken to the power of the given exponent.

Description

The Math.pow() function returns the base to the exponent power, that is, baseexponent, the base and the exponent are in decimal numeral system.

Because pow() is a static method of Math, you always use it as Math.pow(), rather than as a method of a Math object you created (Math has no constructor). If the base is negative and the exponent is not an integer, the result is NaN.

Examples

Using Math.pow()

// simple
Math.pow(7, 2);    // 49
Math.pow(7, 3);    // 343
Math.pow(2, 10);   // 1024
// fractional exponents
Math.pow(4, 0.5);  // 2 (square root of 4)
Math.pow(8, 1/3);  // 2 (cube root of 8)
Math.pow(2, 0.5);  // 1.4142135623730951 (square root of 2)
Math.pow(2, 1/3);  // 1.2599210498948732 (cube root of 2)
// signed exponents
Math.pow(7, -2);   // 0.02040816326530612 (1/49)
Math.pow(8, -1/3); // 0.5
// signed bases
Math.pow(-7, 2);   // 49 (squares are positive)
Math.pow(-7, 3);   // -343 (cubes can be negative)
Math.pow(-7, 0.5); // NaN (negative numbers don't have a real square root)
// due to "even" and "odd" roots laying close to each other,
// and limits in the floating number precision,
// negative bases with fractional exponents always return NaN
Math.pow(-7, 1/3); // NaN

Specifications

Specification
ECMAScript (ECMA-262) The definition of 'Math.pow' in that specification.

Browser compatibility

BCD tables only load in the browser

See also

• Math.cbrt()
• Math.exp()
• Math.log()
• Math.sqrt()
• Exponentiation operator