# NaN value

The `NaN` value (abbreviation for Not-A-Number) means "not a number". This value occurs when trying to perform an invalid mathematical operation.

## Example

Let's multiply a string with letters by a number:

`console.log('aaa' * 3);`

The code execution result:

`NaN`

## Example

Let's try to divide one string by another:

`console.log('aaa' / 'bbb');`

After executing the code, we will also get `NaN`:

`NaN`

## Example

Now let's add the `NaN` value with a number:

`console.log(NaN + 3);`

The code execution result:

`NaN`

## See also

- the `isNaN` function
  that checks for `NaN`

← →
↑
en ru