in reply to matching the + character

+ is a special character in regular expressions that means match one or more of what is before me... your regexp will match one or more a's followed by a b... i.e. aaab ab aaaaaab, to match a plus you must escape it, using a \ so \+ will match a plus... see perlre

Update Doh, my eyes skipped the lower text... :)

you need the \\ because "" interploates data, thus converting \+ to + before it gets to the regexp... if you use single quotes 'a\+b' then you will be ok.

                - Ant
                - Some of my best work - Fish Dinner

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Re: Re: matching the + character
by Anonymous Monk on Aug 06, 2001 at 22:10 UTC 
     use strict;
      3 my $var1 = "a+b";
      4 my $var2 = "a+b";
      5 if ($var1 =~ /\Q$var2\E/) {
      6     print "hey it matches \n";
      7 }
      8
      9 print "hey here  \n";
     10

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Re: Re: matching the + character
by jalebie (Acolyte) on Aug 06, 2001 at 21:48 UTC
    I know that thats i even tried matching by setting 
    use strict;

my $var1 = "a+b";
my $var2 = "a\+b";
if ($var1 =~ /$var2/) {
    print "hey it matches \n";
}

print "hey here  \n";

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    but it doesn't work. AGAIN the only thing that works is 
    $var2 = "a\\+b";

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    please explain Waris
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