foreach my $i (
    sort {
### $b is a reference not an index number
###     $hash{array1}[$b][1]
        $b->[1]
        <=>
### $a is a reference not an index number
###     $hash{array1}[$a][1] 
        $a->[1]
    }
    @{$hash{array1}}
) {
    print @$i[1], "\n";
}