regex allow only numbers or empty string

Question

Can someone help me create this regex. I need it to check to see if the string is either entirely whitespace(empty) or if it only contains positive whole numbers. If anything el

Answer 1

Kobi has a good answer but technically you don't have to capture it (unless you're going to do something the output)

/^[\s\d]+$/

Or if you don't care if the string is completely empty (i.e. "")

/^[\s\d]*$/

To clarify I understood the original question to mean whitespace in the string should be ignored.