The Number.isInteger() method determines whether the passed value is an integer.

Syntax

Number.isInteger(value)

Parameters

value
The value to be tested for being an integer.

Return value

A Boolean indicating whether or not the given value is an integer.

Description

If the target value is an integer, return true, otherwise return false. If the value is NaN or infinite, return false.

Examples

Number.isInteger(0);         // true
Number.isInteger(1);         // true
Number.isInteger(-100000);   // true
Number.isInteger(99999999999999999999999); // true

Number.isInteger(0.1);       // false
Number.isInteger(Math.PI);   // false

Number.isInteger(NaN);       // false
Number.isInteger(Infinity);  // false
Number.isInteger(-Infinity); // false
Number.isInteger('10');      // false
Number.isInteger(true);      // false
Number.isInteger(false);     // false
Number.isInteger([1]);       // false

Polyfill

Number.isInteger = Number.isInteger || function(value) {
  return typeof value === 'number' && 
    isFinite(value) && 
    Math.floor(value) === value;
};

Specifications

Specification Status Comment
ECMAScript 2015 (6th Edition, ECMA-262)
The definition of 'Number.isInteger' in that specification.
Standard Initial definition.
ECMAScript Latest Draft (ECMA-262)
The definition of 'Number.isInteger' in that specification.
Draft  

Browser compatibility

Update compatibility data on GitHub
DesktopMobileServer
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidSafari on iOSSamsung InternetNode.js
Basic supportChrome Full support YesEdge Full support YesFirefox Full support 16IE No support NoOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 16Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yesnodejs Full support 0.12

Legend

Full support  
Full support
No support  
No support

See also

  • The Number object it belongs to.

Document Tags and Contributors

Last updated by: wbamberg,