Re^2: capture value from two patterns (updated)

It's also ambiguous if all matches fail:

c:\@Work\Perl\monks>perl -wMstrict -le
"for (qw(a X b)) {
   /(a)/ or /(b)/;
   my $id = $1;
   print qq{'$_' -> '$id'};
   }
"
'a' -> 'a'
'X' -> 'a'
'b' -> 'b'
[download]

Update 1: Something like
my $id = $1 // $2 if m!/key/(\d+)|/(\d+)-\d+!;
(if you avoid the problem of the conditionally declared lexical!) does not suffer this:

c:\@Work\Perl\monks>perl -wMstrict -le
"for (qw(a X b)) {
   /(a)|(b)/ or next;
   my $id = $1 // $2;
   print qq{'$_' -> '$id'};
   }
"
'a' -> 'a'
'b' -> 'b'
[download]

Update 2: Slight wording change to first sentence.

Give a man a fish: <%-{-{-{-<

Comment on Re^2: capture value from two patterns (updated) Select or Download Code

Replies are listed 'Best First'.
Re^3: capture value from two patterns (updated) by LanX (Saint) on Aug 20, 2020 at 23:37 UTC
good point, $1 sticks to the last successful match so always check before accessing it `for (qw(a X b)) { my $id = $1 if /(a)/ or /(b)/; print qq{'$_' -> '$id'\n}; }` [download] `C:/Perl_524/bin\perl.exe -w d:/exp/pm_or_regex.pl Use of uninitialized value $id in concatenation (.) or string at d:/ex +p/pm_or_regex.pl line 5. 'a' -> 'a' 'X' -> '' 'b' -> 'b'` [download] I kept the warning in intentionally. Cheers Rolf _{(addicted to the Perl Programming Language :) Wikisyntax for the Monastery}	[reply] [d/l] [select]

Replies are listed 'Best First'.

Re^3: capture value from two patterns (updated)
by LanX (Saint) on Aug 20, 2020 at 23:37 UTC

so always check before accessing it

for (qw(a X b)) {
    my $id = $1
      if /(a)/ or /(b)/;

   print qq{'$_' -> '$id'\n};

}
[download]

C:/Perl_524/bin\perl.exe -w d:/exp/pm_or_regex.pl Use of uninitialized value $id in concatenation (.) or string at d:/ex +p/pm_or_regex.pl line 5. 'a' -> 'a' 'X' -> '' 'b' -> 'b'
[download]

I kept the warning in intentionally.

Cheers Rolf
_{(addicted to the Perl Programming Language :)

Wikisyntax for the Monastery}

[reply]
[d/l]
[select]