NumberConstructor.isNumber method

NumberConstructor › isNumber

Official

Type guard to check if a value is a number.

Signature:

isNumber(obj: unknown): obj is number

Parameters:

Parameter	Type	Description
obj	unknown	The value to check.

Returns: obj is number — true if the value is a number, false otherwise.

Remarks:

Regarding NaN see: https://forum.obsidian.md/t/bug-number-isnumber-definition/98104.

Example:

console.log(Number.isNumber(123)); // true
console.log(Number.isNumber('123')); // false
console.log(Number.isNumber(NaN)); // true
console.log(Number.isNumber(Infinity)); // true
console.log(Number.isNumber(-Infinity)); // true