i am sorry if some has already posted this. why grep behaves differently , when we use expression and using the output of the expression directly in the place of expression 

my $t = 1;
print grep {$t^=1} qw( a b c d e );

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and using 0 directly instead using expression $t^=1 below 

my $t = 1;

print grep {0} qw( a b c d e );

my $t = 1;

print grep {$t} qw( a b c d e );

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20090717 Janitored by Corion: Added formatting, code tags, as per Writeup Formatting Tips

In reply to grep function usage by rgadireddy

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