Beefy Boxes and Bandwidth Generously Provided by pair Networks
We don't bite newbies here... much

Re: Reading Reg Exp

by dasgar (Priest)
on Aug 11, 2010 at 13:16 UTC ( #854363=note: print w/replies, xml ) Need Help??

in reply to Reading Reg Exp

If you're wanting to learn about regular expressions, I'd recommend checking out Mastering Regular Expressions. The author not only explains regular expressions, but also discusses how regular expression engines work and how that impacts the regular expression syntax. It's a good reference book to have handy.

As for your question on (?=\d), that's a zero width look ahead. Basically your second regular expression is looking for the first occurrence of the word 'man' that is immediately followed by a digit and then replaces 'man' with 'cat'. That's assuming that you didn't accidentally forget to include modifiers after the last / in your post.

For example, if your string was man mantis man1 man2 man15, the second regular expression that you provided would change that to man mantis cat1 man2 man15.

Log In?

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://854363]
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others imbibing at the Monastery: (3)
As of 2021-05-13 09:21 GMT
Find Nodes?
    Voting Booth?
    Perl 7 will be out ...

    Results (134 votes). Check out past polls.