Re: sorting hash ref

cool_jr256's post explains what's wrong with your code, so the following is a relatively minor point. There's no need to follow a the sort with reverse. Just reverse the order of the $a/$b comparison:

foreach my $sorted_url ( sort { $hash{$b}->{'hits'} <=>
                                $hash{$a}->{'hits'} ) keys %hash ) {
[download]

Update: Revised wording slightly.

the lowliest monk

Comment on Re: sorting hash ref Download Code

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Re^2: sorting hash ref by salva (Canon) on Jun 10, 2005 at 14:43 UTC
`reverse sort { my_cmp($a, $b) } @foo # (1)` [download] and `sort { my_cmp($b, $a) } @foo # (2)` [download] are not strictly equivalent: order is reversed for terms comparing as equal. For instance: `@u = map { [$_, $i++] } (0,0,3,2,2); $" = '-'; print( (map {$_->[1]} reverse sort { $a->[0] <=> $b->[0] } @u), "\n", (map {$_->[1]} sort { $b->[0] <=> $a->[0] } @u), "\n" );` [download] prints `24310 23401` [download] though I believe that most of the times, the correct solution is actually the second one or it just doesn't mind at all!	[reply] [d/l] [select]
Re^3: sorting hash ref by halley (Prior) on Jun 10, 2005 at 14:59 UTC
Your assertion about stable sort ordering is true, though I'd add that you cannot depend on ANY sort order when iterating through the keys of a normal hash. Even two successive runs using the same hash full of data may give different ordering, since (1) it may be influenced by insertion order, and (2) it may be influenced by insertion attack protections, and (3) it may be influenced by other changes in the algorithms between versions of perl. -- `[ e d @ h a l l e y . c c ]`	[reply]