Re: Sorting a hash by value, and displaying the key

[Timothy Kimball]

David Michael wrote:
:     I have a hash that needs to be displayed in a certain order. I tried
:     
:     foreach $key (sort (keys %HASH)) {
:         print $key;
:     }
: 
:     that sorts alphabetically. I need it in the order it was inserted, so I made the 
:value a number that increased for each key. I need to sort by the value, but display 
:the key. Any ideas ?

You can provide sort() with a subroutine that prescribes how to do the
pairiwse comparisons:

        foreach $key (sort { $HASH{$a} <=> $HASH{$b} } keys %HASH ) {
                print $key;
        }

Or you can use the Tie::IxHash module- available on CPAN- which allows
you to create hashes that preserve the order in which the keys were
created:

        use Tie::IxHash;
        tie %HASH => tie 'Tie::IxHash';
        foreach $key (sort keys %HASH) {
                print $key;
        }

Then it doesn't matter what the %HASH values are.

-- tdk