Question

I wrote a regex for finding id values of html elements:

<.+ id\s*=\s*["'](.+)["'].*/?>

For most cases it returns id values, but not for this one:

<input type="hidden" name="__EVENTTARGET" id="__EVENTTARGET" value="" />

It matches the following group value:

__EVENTTARGET" value="

instead of the expected __EVENTTARGET.

What is wrong in the regex?

Answer 1

Your expression (.+) is “greedy” — it matches as much as it can.

There are 2 solutions:

“Lazy” (non-greedy): this will match as few characters as possible

(.+?)

or a better solution, instead of matching . you should match [^'"]:

([^'"]+)