PHP strip punctuation

Question

Let\'s say I have this:

$hello = \"Hello, is StackOverflow a helpful website!? Yes!\";

and I want to strip punctuation so it outputs as:

Answer 1

I'd go with something like this:

$str = preg_replace('/[^\w\s]/', '', $str);

I don't know if that's more broad than you're looking for, but it sounds like what you're trying to do.

I also notice you've replaced spaces with underscores in your sample. The code I'd use for that is:

$str = preg_replace('/\s+/', '_', $str);

Note that this will also collapse multiple spaces into one underscore.