正则表达式多个匹配PHP

Question

I'm trying to get all numbers from a string, having - or _ before the number and optional - _ space or the end of string at the end of the number.

So, my regex looks like this:

[-_][\d]+[-_ $]?

My problem is, I don't match numbers right after each other. From a "foo-5234_2123_54-13-20" string, I only get 5234 , 54 and 20 .

What I tried is the following regexes: (?:[-_])[\\d]+(?:[-_ $])? and [-_]([\\d]+)[-_ $]? that obviously didn't work. I'm looking for hours now and I know it can't be that hard so I hope someone can help me here.

If that makes any difference, I'm using PHP preg_match_all .

Answer 1

You just need to use look-arounds :

(?<=[-_])\d+(?=[-_ ]|$)

See demo

Fortunately, PHP supports at least fixed-width look-behinds, and we can use it here.