Sort and Print Multidimensional Hash

[Larry]

Hi!,

I have a multi dimensional hash made up like this below:

my $global = {};
$global->{"KEY1"}->{"ID"} = k;
$global->{"KEY1"}->{"VALUE1"} = "...";
$global->{"KEY1"}->{"VALUE2"} = "...";

$global->{"KEY2"}->{"ID"} = k;
$global->{"KEY2"}->{"VALUE1"} = "...";
$global->{"KEY2"}->{"VALUE2"} = "...";

Now I'd like to sort it by ID (0..1) then print it, is there an easy way to
do that?

thanks

 

[Jürgen Exner]

Hi!,

I have a multi dimensional hash made up like this below:

my $global = {};
$global->{"KEY1"}->{"ID"} = k;
$global->{"KEY1"}->{"VALUE1"} = "...";
$global->{"KEY1"}->{"VALUE2"} = "...";

$global->{"KEY2"}->{"ID"} = k;
$global->{"KEY2"}->{"VALUE1"} = "...";
$global->{"KEY2"}->{"VALUE2"} = "...";

Now I'd like to sort it by ID (0..1) then print it, is there an easy way to
do that?

No, the way you stated your question it is impossible because hashes do
not have an order and therefore cannot be sorted.

However, if you rephrase your question in a more meaningful way like
e.g. "how can I sort the keys of %global such that they are sorted by
the value of ID", then the challenge becomes trivial to solve:
Just sort() the keys() of %global, using {$global->$_->'ID'} as the
compare function for sort().

And then loop through the the sorted keys and print the associated hash
elements in that order.

jue

 

[Jürgen Exner]

No, the way you stated your question it is impossible because hashes do
not have an order and therefore cannot be sorted.

However, if you rephrase your question in a more meaningful way like
e.g. "how can I sort the keys of %global such that they are sorted by
the value of ID", then the challenge becomes trivial to solve:
Just sort() the keys() of %global, using {$global->$_->'ID'} as the
compare function for sort().

Actually, this is very poorly worded, let me rephrase:
.... comparing $global->$a->'ID' and $global->$b->'ID' in the compare
function for sort().

jue