---
title: math.isNaN() function
description: The math.isNaN() function reports whether `f` is an IEEE 754 “not-a-number” value.
menu:
  v2_0_ref:
    name: math.isNaN
    parent: Math
weight: 301
---

The `math.isNaN()` function reports whether `f` is an IEEE 754 “not-a-number” value.

_**Output data type:** Boolean_

```js
import "math"

math.isNaN(f: 12.345)

// Returns false
```

## Parameters

### f
The value used in the evaluation.

_**Data type:** Float_

## Special cases
```js

```