Question

What’s the regular expression for positive whole numbers only? (zero is not allowed)

I was able to get the regular expression for numbers only which is ^\d+$. I’ve been trying to look for one online but it’s already been an hour so I’ve decided to post it here on Stack Overflow.

matches:

1 || 2 || 444 || 9000 || 012

non-matches:

9.2 || -90

Answer 1

May be you are looking for ^[1-9]+$ pattern. It’ll match 1245, 2253 etc. But not 1003. or 0124. If you want to match the 3rd number (1003) as well use ^[1-9]\d*$ pattern.

In php you’d use

preg_match('/^[1-9]\d*$/', $subject, $matches)