using m// while iterating through an array

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

I'm having a problem with the following code (the if() statement never executes):

foreach (@banned_channels) {
	if ($channels =~ /$_/i) {
		IRC::print "match: $_";
	}
}

The @banned_channels are loaded from a file (I've verified that this is working fine). I've also made sure that the values of $channel and $_ are both correct on each iteration of the loop. Still, no matches are being made. Am I making some newbie mistake in my use of $_ as a regexp? Oh, if it helps the value of $channels usually looks something like "#help #blah #irc". I suppose I could also post the full source code if the problem seems to be elsewhere. Thanks.

Comment on using m// while iterating through an array

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Re: using m// while iterating through an array by chromatic (Archbishop) on Sep 22, 2000 at 08:19 UTC
This works for me: `#!/usr/bin/perl -w use strict; chomp(my @banned_channels = <DATA>); my $channels = "#gross_people #skriptk1dd13\$ #trolls"; sub IRC::print { print "@_\n"; } foreach (@banned_channels) { if ($channels =~ /$_/i) { IRC::print "match: $_"; } } __END__ #trolls #flamers #lusers #litterbugs` [download] However, I'd use a hash: `my $channels = "#gross_people #skriptk1dd13\$ #trolls"; my %banned; @banned{split " ", $channels} = (1); foreach (@banned_channels) { if (exists($banned{$_})) { IRC::print "match: $_"; } }` [download]	[reply] [d/l] [select]
Re: using m// while iterating through an array by japhy (Canon) on Sep 22, 2000 at 15:20 UTC
If you're using a hash, you can probably speed things up by taking a hash slice with `@banned_channels` as a set of keys: `my @channels = split / /, '#perl #math #rpi #perlmonks'; my %where; @where{@channels} = @channels; @banned_in = map $_ ? $_ : (), @where{@banned};` [download] Then again, I could be off my rocker. `$_="goto+F.print+chop;\n=yhpaj";F1:eval`	[reply] [d/l]
Re: using m// while iterating through an array by Anonymous Monk on Sep 22, 2000 at 09:54 UTC
Wow, thanks for the awesome (and quick) reply. Adding chomp onto the line that reads in the array seems to have been the solution to the problem.	[reply]