# is_alnum

Checks if a string is alphanumeric.

```tql
is_alnum(x:string) -> bool
```

## Description

The `is_alnum` function returns `true` if `x` contains only alphanumeric characters and `false` otherwise.

## Examples

### Check if a string is alphanumeric

```tql
from {x: "hello123".is_alnum()}
```

```tql
{x: true}
```

## See Also

* [`is_alpha`](https://preview.docs.tenzir.com/375/375/reference/functions/is_alpha.md)
* [`is_numeric`](https://preview.docs.tenzir.com/375/375/reference/functions/is_numeric.md)
* [`is_printable`](https://preview.docs.tenzir.com/375/375/reference/functions/is_printable.md)
* [Manipulate strings](https://preview.docs.tenzir.com/375/375/guides/transformation/manipulate-strings.md)