How to remove all characters from a string, except the integers?

[Salih Dincer]

On Thursday, 3 March 2022 at 13:25:32 UTC, Stanislav Blinov wrote:
>	
>         auto filtered = () {
>             auto r = args[1].find!isNumber; // check if a 
> string contains integers
> ```

**When using ```find!isNumber```:**
```
0123456789
@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_
`abcdefghijklmnopqrstuvwxyz{|}~
```

**When using ```find!isAlphaNum```:**
```
0123456789
```