Skip to content

@technobuddha > library > Object > Type Guards

Function: isNumber() ​

ts
function isNumber(value: unknown): value is number;

Defined in: is-number.ts:16

Determines whether the provided value is a number or a Number object.

Parameters ​

ParameterTypeDescription
valueunknownThe value to test.

Returns ​

value is number

True if the value is a number or a Number object; otherwise, false.

Example ​

typescript
isNumber(42); // true
isNumber(new Number(42)); // true
isNumber(NaN); // true
isNumber('42'); // false
isNumber(null); // false