To expand upon the AnonMonk's suggestion.
Maybe this helps to show what is going on?
#!/usr/bin/perl -w
use strict;

my $string = "Twinkle twinkle little star";

my @matches = $string =~ m/twinkle/ig;
print "Matches are: @matches\n";  # Matches are: Twinkle twinkle
print "Number of matches: ",scalar @matches,"\n"; 
print "\n";

# this is the same without creating @matches
# the () is a list and $n here is number of things
# in that list

#
# Without the intervening ()=, to force list context,
# you just get the "truthfulness" (0,1) of the match
# with this, you get the number of things in the list
# without having to create a named array (@matches)

my $n = () = $string =~ m/twinkle/ig;
print "Number of occurences = $n\n";

__END__
Matches are: Twinkle twinkle
Number of matches: 2

Number of occurences = 2

[download]
PS: I try to avoid assigning to $_ when possible (and sometimes this is necessary), but I figure that $_ "belongs to Perl". The expression: 
foreach ($string)
{
   s/^\s*//; #delete leading spaces
   s/\s*$//; #delete trailing spaces
}

[download]
is seen often and has this effect of assigning $string to $_. $string gets modified due to "aliasing".

In reply to Re: Error in my Regular expression pattern by Marshall
in thread Error in my Regular expression pattern by shajiindia

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