my @myMainArray = map { [ $myArray[$_] .. $myArray[$_+4] ] } grep { !($_ % 5) } 0 .. $#myArray; #### my @myMainArray = map { exists $myArray[ $_+4 ] ? [ $myArray[$_] .. $myArray[$_+4] ] : [ $myArray[$_] .. $myArray[-1] ] } grep { !($_ % 5) } 0 .. $#myArray;