mozilla
Your Search Results

    Math.abs()

    The Math.abs() function returns the absolute value of a number, that is

    Math.abs(x)=|x|={xifx>00ifx=0-xifx<0{\mathtt{\operatorname{Math.abs}(x)}} = {|x|} = \begin{cases} x & \text{if} \quad x \geq 0 \\ -x & \text{if} \quad x < 0 \end{cases}

    Syntax

    Math.abs(x)

    Parameters

    x
    A number.

    Description

    Because abs() is a static method of Math, you always use it as Math.abs(), rather than as a method of a Math object you created (Math is not a constructor).

    Examples

    Behavior of Math.abs()

    Passing a non-numeric string or undefined/empty variable returns NaN. Passing null returns 0.

    Math.abs('-1');     // 1
    Math.abs(-2);       // 2
    Math.abs(null);     // 0
    Math.abs('string'); // NaN
    Math.abs();         // NaN
    

    Specifications

    Specification Status Comment
    ECMAScript 1st Edition (ECMA-262) Standard Initial definition. Implemented in JavaScript 1.0.
    ECMAScript 5.1 (ECMA-262)
    The definition of 'Math.abs' in that specification.
    Standard  
    ECMAScript 2015 (6th Edition, ECMA-262)
    The definition of 'Math.abs' in that specification.
    Standard  

    Browser compatibility

    Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
    Basic support (Yes) (Yes) (Yes) (Yes) (Yes)
    Feature Android Chrome for Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
    Basic support (Yes) (Yes) (Yes) (Yes) (Yes) (Yes)

    See also

    Document Tags and Contributors

    Last updated by: fscholz,