sub is_in_list { return !!grep { $_ eq $_[0] } @_[ 1 .. $#_ ]; } print "baz is in list" if is_in_list 'baz', qw/ foo bar baz /; __output__ baz is in list #### use Data::Dumper; my $val = 'a string which evaluates to true'; print Dumper !$val; print Dumper !!$val; __output__ $VAR1 = ''; $VAR1 = '1';