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    isFinite()

    Summary

    The global isFinite() function determines whether the passed value is a finite number. If needed, the parameter is first converted to a number.

    Syntax

    isFinite(testValue)

    Parameters

    testValue
    The value to be tested for finiteness.

    Description

    isFinite is a top-level function and is not associated with any object.

    You can use this function to determine whether a number is a finite number. The isFinite function examines the number in its argument. If the argument is NaN, positive infinity, or negative infinity, this method returns false; otherwise, it returns true.

    Examples

    isFinite(Infinity);  // false
    isFinite(NaN);       // false
    isFinite(-Infinity); // false
    
    isFinite(0);         // true
    isFinite(2e64);      // true
    
    
    isFinite("0");       // true, would've been false with the 
                         // more robust Number.isFinite("0")
    

    Specifications

    Specification Status Comment
    ECMAScript 2nd Edition. Standard Initial definition.
    ECMAScript 5.1 (ECMA-262)
    The definition of 'isFinite' in that specification.
    Standard  
    ECMAScript 2015 (6th Edition, ECMA-262)
    The definition of 'isFinite' 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

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    Last updated by: imsaar,
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