Can I copy a hash without resetting its “each” iterator?

Question

I am using each to iterate through a Perl hash:

while (my ($key,$val) = each %hash) {
   ...
}

Then something interesting happ

Answer 1

Let's not forget that keys %hash is already defined when you enter the while loop. One could have simply saved the keys into an array for later use:

my @keys = keys %hash;

while (my ($key,$val) = each %hash) {

    if (something_interesting_happens()) {

        print "$_ => $hash{$_}\n" for @keys;
    }
}

Downside:

• It's less elegant (subjective)
• It won't work if %hash is modified (but then why would one use each in the first place?)

Upside:

• It uses less memory by avoiding hash-copying