Check if string contains only digits

Question

I want to check if a `string` contains only digits. I used this: ``` var isANumber = isNaN(theValue) === false; if (isANumber){ .. } ``` But realized that it also allows `+` and `-`. Basically, I want to make sure an `input` contains ONLY digits and no other characters. Since `+100` and `-5` are both numbers, `isNaN()` is not the right way to go. Perhaps a regexp is what I need? Any tips?

Accepted Answer

how about

```
let isnum = /^\d+$/.test(val);
```

Check if string contains only digits

Solution

Problem