regex to separate HTML GET parameters

问题

How can I use a regular expression to separate GET parameters in a URI and extract a certain one? Specifically, I'm trying to get just the v= part of a YouTube watch URI. I've come up with youtube.com\/watch\?(\w+=[\w-]+&?)*(v=[\w-]+)&?*(\w+=[\w-]+&?)*, but that looks awfully repetitive. Is there a better (shorter?) way to do this?

回答1:

A simplified regex :

^(?:http://www.)?youtube.[^/]+?/watch?(.?)(v=([^&]+))(.)$

回答2:

I know there are a lot of similar questions out there, but none has quite what I wanted. I'm looking for something capable of pulling out just the video ID—regardless of whether it's first in the parameter list, last, or buried in between others. Nothing I've seen has worked quite like that yet.

For reference, I'm using this web app for testing, and this set of test URIs:

http://www.youtube.com/watch?v=XXXXXXXXXXX
http://www.youtube.com/watch?v=XXXXXXXXXXX&feature=results_video&playnext=1&list=XXXXXXXXXXXXXXXXXX
http://www.youtube.com/watch?feature=player_embedded&v=XXXXXXXXXXX#!
http://www.youtube.com/watch?annotation_id=annotation_xxxxxx&feature=iv&src_vid=XXXXXXXXXXX&v=XXXXXXXXXX

Fellow Stack Exchangers, I propose the following regular expression to solve this:
youtube.com\/watch\?(\S*)v=([\w-]+)

来源：https://stackoverflow.com/questions/12812985/regex-to-separate-html-get-parameters