I did a little playing with this, to try to learn something.
%h = (1 => 2, a=>"b", c => 2);
%h = reverse (%x = reverse %h);
foreach my $n (keys %h) {
print "$n $h{$n}\n";
}
Yeah, I know. Anyway, here's what I get:
2
1 2
a b
As if a duplicate element were eliminated by making the key null. But if I do
%h = (1 => 2, a=>"b", c => 2);
%x = reverse %h;
%h = reverse %x;
foreach my $n (keys %h) {
print "$n $h{$n}\n";
}
I get
1 2
a b
which is what I'd expect. Now, here's yet another thing: if I create another duplicate, d => 2 (at the end of the list), I still get the same end result; that duplicate is eliminated. In fact, in the first bit of code, I still get three lines of output. If there are duplicates, it doesn't seem to be guaranteed which one is eliminated by the reverse. I just looked at reverse in my Camel book and it doesn't mention anything about duplicates, so I suspect the order can't be relied upon. Typical for a hash.