Perl, convert hash to array

Question

If I have a hash in Perl that contains complete and sequential integer mappings (ie, all keys from from 0 to n are mapped to something, no keys outside of this), is there a mean

Answer 1

This will leave keys not defined in %hashed_keys as undef:

# if we're being nitpicky about when and how much memory
# is allocated for the array (for run-time optimization):
my @keys_arr = (undef) x scalar %hashed_keys;

@keys_arr[(keys %hashed_keys)] =
    @hashed_keys{(keys %hashed_keys)};

And, if you're using references:

@{$keys_arr}[(keys %{$hashed_keys})] = 
    @{$hashed_keys}{(keys %{$hashed_keys})};

Or, more dangerously, as it assumes what you said is true (it may not always be true … Just sayin'!):

@keys_arr = @hashed_keys{(sort {$a <=> $b} keys %hashed_keys)};

But this is sort of beside the point. If they were integer-indexed to begin with, why are they in a hash now?