Re^2: sorting hash by a certain value (that it is in an array)

this is not about sorting an array, it's about sorting an hash that has arrays in it. the example by brx created a new sorted array @sorted_books. I need the %books hash to be sorted as so:

%books=(
   '54' => ['enlgish', 'bob falicas', 17], 
   '34' => ['enlgish', 'dani M. rod', 54],
   '24' => ['spanish', 'ramk rovale', 41],
);
[download]

I don't see how the example by brx gives me that. when I print out the %books hash using this:

while (my($key, $value) = each(%books)){
    print "$key: $value\n";
}
[download]

I get the same unsorted result.

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Re^3: sorting hash by a certain value (that it is in an array) by Corion (Patriarch) on Jul 17, 2012 at 13:34 UTC
A hash cannot be sorted, as its keys have no order. You need to generate your list from the hash, then sort that list. This is a FAQ. Please (again!) read perlfaq4, this time on How do I sort a hash (optionally by value instead of key)?.	[reply]
Re^3: sorting hash by a certain value (that it is in an array) by jethro (Monsignor) on Jul 17, 2012 at 13:35 UTC
A hash is a different data structure than an array. Its advantage is that it allows arbitrary strings as keys instead of just a number. The disadvantage is that it can't be sorted. Read about "hash tables" on wikipedia if you want to know why.	[reply]
Re^3: sorting hash by a certain value (that it is in an array) by clueless newbie (Curate) on Jul 17, 2012 at 16:06 UTC
Perhaps you could use Tie::IxHash? `my %unordered=(...); tie my %ordered, "Tie::IxHash"; for my $key (sort {$unordered{$a}[1] cmp $unordered{$b}[1]} keys %$ +unordered) { $ordered{$key}=$unordered->{$key}; };` [download]	[reply] [d/l]
Re^3: sorting hash by a certain value (that it is in an array) by brx (Pilgrim) on Jul 17, 2012 at 15:50 UTC
I don't see how the example by brx gives me that. See my update at Re: sorting hash by a certain value (that it is in an array).	[reply]