The Number.isFinite() static method determines whether the passed value is a finite number — that is, it checks that a given value is a number, and the number is neither positive Infinity, negative Infinity, nor NaN.
Number.isFinite()
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Syntax
js
Number.isFinite(value)
Parameters
-
value -
The value to be tested for finiteness.
Return value
The boolean value true if the given value is a finite number. Otherwise false.
Examples
Using isFinite()
js
Number.isFinite(Infinity); // false
Number.isFinite(NaN); // false
Number.isFinite(-Infinity); // false
Number.isFinite(0); // true
Number.isFinite(2e64); // true
Difference between Number.isFinite() and global isFinite()
In comparison to the global isFinite() function, this method doesn't first convert the parameter to a number. This means only values of the type number and are finite return true, and non-numbers always return false.
js
isFinite("0"); // true; coerced to number 0
Number.isFinite("0"); // false
isFinite(null); // true; coerced to number 0
Number.isFinite(null); // false
Specifications
| Specification |
|---|
| ECMAScript Language Specification # sec-number.isfinite |
Browser compatibility
| Desktop | Mobile | Server | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chrome | Edge | Firefox | Opera | Safari | Chrome Android | Firefox for Android | Opera Android | Safari on IOS | Samsung Internet | WebView Android | Deno | Node.js | ||
isFinite |
19 | 12 | 16 | 15 | 9 | 25 | 16 | 14 | 9 | 1.5 | 4.4 | 1.0 | 0.10.0 | |
See also
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https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number/isFinite