Number.isFinite()

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 {{jsxref("Infinity")}}, negative Infinity, nor {{jsxref("NaN")}}.

{{InteractiveExample("JavaScript Demo: Number.isFinite()")}}

```js interactive-example console.log(Number.isFinite(1 / 0)); // Expected output: false

console.log(Number.isFinite(10 / 5)); // Expected output: true

console.log(Number.isFinite(0 / 0)); // Expected output: false

## Syntax

```js-nolint
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()#

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 {{jsxref("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.

isFinite("0"); // true; coerced to number 0
Number.isFinite("0"); // false
isFinite(null); // true; coerced to number 0
Number.isFinite(null); // false

Specifications#

{{Specifications}}

Browser compatibility#

{{Compat}}

See also#

• Polyfill of Number.isFinite in core-js
• es-shims polyfill of Number.isFinite
• {{jsxref("Number")}}
• {{jsxref("isFinite()")}}