Javascript Regex Match the first the occurrence

Question

Hi,

I've this regex (which doesn't do what i want): /^.*\/(eu|es)(?:\/)?([^#]*).*/ which actually is the js version of: /^.*/(eu|es)(?:/)?([^#]*).*/

Well, it doesn't do what i want, of course it works. :) Given this URLs:

• http://localhost/es -> [1] = es, [2] = ''
• http://localhost/eu/bla/bla#wop -> [1] = eu, [2] = 'bla/bla'
• http://localhost/eu/bla/eubla -> [1] = eu, [2] = 'bla'

The first two urls work as i expected. The third one is not doing what i want. As "eu" is found later on the url, it does the match with the second eu instead of the first one. So I would like it to match this: [1] = 'eu', [2] = 'bla/eubla'

How must I do it?

Thank you. :)

Answer 1

I think what you want is nongreedy repetition for the first repetition character *. Try this:

/^.\*?\/(eu|es)(?:\/)?([^#]\*).\*/

The only difference is the question mark ? after the first *. If this is missing, the * will match as many characters as possible, leading to the undesired behaviour in your third example.

Answer 2

Make the first * ungreedy

/^.\*?\/(eu|es)(?:\/)?([^#]\*).\*/

Btw, do you really need to escape * in javascript? Won't this work?

/^.*?\/(eu|es)(?:\/)?([^#]*).*/

Answer 3

The above answers re the greedy versus non-greedy are fine, but why bother matching the start of the URL anyway? Just start your expression with:

/\/(eu|es)

and it will match the first one found on the line.