---
title: "isNumber"
description: "A TypeScript type guard that checks whether a value is a finite number, excluding NaN, so numeric logic stays safe and predictable."
canonical_url: "https://core.mhaibaraai.cn/en/docs/validators/is-number"
---
# isNumber

> A TypeScript type guard that checks whether a value is a finite number, excluding NaN, so numeric logic stays safe and predictable.

## Usage

Check whether a value is a number, excluding `NaN`. This is a TypeScript type guard function.

```ts
import { isNumber } from '@movk/core'

isNumber(123) // => true
isNumber(0) // => true
isNumber(Number.NaN) // => false
isNumber('123') // => false
```

## API

`isNumber(value: any): value is number`

### Parameters

**value** (`any`) *required*: The value to check.

### Returns

**boolean**: Returns true if the value is a valid number (not NaN), otherwise false.

## Changelog

See commit history for [src/validators/isNumber.ts](https://github.com/mhaibaraai/movk-core/commits/main/src/validators/isNumber.ts).

---

- [GitHub](https://github.com/mhaibaraai/movk-core/blob/main/src/validators/isNumber.ts)


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