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Regex and replacing groups

Tim Patton

Joined: Oct 17, 2006
Posts: 7
I'm trying to figure out how to replace just part of a match using the java regex classes (or some other set). Say I have a regex like this:


It will match strings like this: 4-3 100-5656 1-1

I would like to use string replace on the 2nd group, but I am not sure how.

If I use string.replace(, ....) then it will not work correctly in the case of 1-1. I can't use backreferences in string.replace since the '-' isn't included in a group (other than 0). Is this possible with any regex api for java? I know I could include everything in a group, but for my real world usage that could get too complicated.
Jim Yingst

Joined: Jan 30, 2000
Posts: 18671
I can't tell what you're trying to do here. Replace with what? Can you show an example of what you want the result to look like?

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subject: Regex and replacing groups
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