freeCodeCamp/guide/english/javascript/standard-objects/number/number-isfinite/index.md

title
Number isFinite

Number isFinite

Description

The Number.isFinite() method checks if the value passed into it is a finite number. This method was introduced in ES6

Syntax

Number.isFinite(val)

Parameters

val - value to check for finiteness

Return value

A Boolean indicating whether the value is a finite number or not.

Description

Number.isFinite is different from the global isFinite() method, it doesn’t convert the tested value into a number. This means the value needs to be a number and finite to return true.

Examples

Number.isFinite(Infinity)     // false
Number.isFinite(-Infinity)    // false

Number.isFinite(1234)         // true
Number.isFinite(-1.11)        // true
Number.isFinite(0)            // true
Number.isFinite(3g55)         // true

Number.isFinite('1234')       // false
Number.isFinite('Hi')         // false
Number.isFinite('2005/12/12') // false

Number.isFinite('0');         // false, would've been true with
                              // global isFinite('0')
                         
Number.isFinite(null);        // false, would've been true with
                              // global isFinite(null)

More Information:

ECMA 2015 Docs
Number.isFinite() MDN Web Docs