I have an array of data from which I would like to extract rows containing numbers and numbers only. Examples on rows:

15, +2, ' ', 7, 9, +21

(The ' ' represents one or more whitespaces).

In this case I would like to extract only 15, 7 and 9. I use a predicate in the following way:

```
NSString *pattern = @"[^0-9]";
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", pattern];
if (![predicate evaluateWithObject:myStringToMatch])
// Extract ...

```

I have tested my pattern using an online regex tester and found that [^0-9] does match anything but the numbers 0-9. However when I run the above code it only matches the whitespaces and not the eg +2, which I am pretty sure that it should do. Just to clarify, myStringToMatch is an NSString object.

I have no clue why it doesn't match my pattern. Can anyone give me a hint on what I'm doing wrong?

Thanks.