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isNumber

INFO

This function is only available in es-toolkit/compat for compatibility reasons. It either has alternative native JavaScript APIs or isn’t fully optimized yet.

When imported from es-toolkit/compat, it behaves exactly like lodash and provides the same functionalities, as detailed here.

Checks if a given value is a number.

This function can also serve as a type predicate in TypeScript, narrowing the type of the argument to number.

Signature

typescript
function isNumber(value?: unknown): value is number;

Parameters

  • value (unknown): The value to check if it is a number.

Returns

(value is number): Returns true if value is a number, else false.

Examples

typescript
const value1 = 123;
const value2 = 'abc';
const value3 = true;

console.log(isNumber(value1)); // true
console.log(isNumber(value2)); // false
console.log(isNumber(value3)); // false

Released under the MIT License.