Beefy Boxes and Bandwidth Generously Provided by pair Networks
Perl Monk, Perl Meditation
 
PerlMonks  

Re: How do I pass $1 to s///?

by Happy-the-monk (Abbot)
on Jan 06, 2006 at 16:54 UTC ( #521536=note: print w/ replies, xml ) Need Help??


in reply to How do I pass $1 to s///?

backreferences in perlre are used to be written \1, \2 ... tweetiepooh informs me that my perldoc used was outdated... and ikegami again corrects that.

Update: your programme prints "This is fish".
What did you expect it to print? "This is fish 1"?

Further update: see ikegami's solution below.

Third and then fourth update - in italics

Cheers, Sören


Comment on Re: How do I pass $1 to s///?
Re^2: How do I pass $1 to s///?
by Anonymous Monk on Jan 06, 2006 at 17:03 UTC
    > your programme prints "This is fish".
    ...and gives a warning about $1 being uninitialised :(

    > What did you expect it to print? "This is fish 1"?
    Yeah. I've tried "fish \1", "fish \\1", "fish \\\1" as well though with no more luck!
Re^2: How do I pass $1 to s///?
by tweetiepooh (Friar) on Jan 06, 2006 at 17:09 UTC
    \1,\2

    If warnings are on using these lead to
    \1 better written as $1

    There is a section in perlre about it.
Re^2: How do I pass $1 to s///?
by ikegami (Pope) on Jan 06, 2006 at 17:42 UTC

    Still not quite right.

    Backreferences are \1, \2, etc in the LHS (regexp part) of the substitution.
    Backreferences are $1, $2, etc in the RHS (substitituion part) of the substitution.

    Lastest perlre (via [doc://perlre])

Log In?
Username:
Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://521536]
help
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others surveying the Monastery: (6)
As of 2015-07-07 01:48 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    The top three priorities of my open tasks are (in descending order of likelihood to be worked on) ...









    Results (86 votes), past polls