# string_IsAlnum
Returns true if the given `string` is alphanumeric.

## Arguments
- str (string): the string to check.

## Returns
isAlnum (bool): returns `true` if `string` is alphanumeric, otherwise `false`.

## Example
### Ground
```python
call !string_IsAlnum "abc123" &isAlnum
println $isAlnum # true

call !string_IsAlnum "@$!ffasdf" &isAlnum
println $isAlnum # false

call !string_IsAlnum "1234" &isAlnum
println $isAlnum # true

call !string_IsAlnum "_" &isAlnum
println $isAlnum # false
```