#! perl -slw use strict; my @first = map int( -5 + rand 10 ), 1 .. 20; my @second = 1 .. 20; for my $i ( 0 .. $#first ) { if( $first[ $i ] > 0 ) { ## do something with $second[ $i ]; print "first[ $i ] = $first[ $i ]; second[ $i ] == $second[ $i ]"; } } __END__ C:\test>junk38 first[ 2 ] = 2; second[ 2 ] == 3 first[ 3 ] = 4; second[ 3 ] == 4 first[ 7 ] = 2; second[ 7 ] == 8 first[ 8 ] = 2; second[ 8 ] == 9 first[ 9 ] = 3; second[ 9 ] == 10 first[ 10 ] = 4; second[ 10 ] == 11 first[ 12 ] = 1; second[ 12 ] == 13 first[ 18 ] = 1; second[ 18 ] == 19 first[ 19 ] = 1; second[ 19 ] == 20