You can sort the keys of a hash by value also. You can even sort them by value and by key:

my %h;
while (<DATA>) {
    chomp;
    my ($v, $k) = split;
    $h{$k} = $v;
}
print "$h{$_} $_\n" for sort { $h{$a} <=> $h{$b} || $a cmp $b } keys %
+h;
__DATA__
1 Flu
1 Cold
2 Diabetics
4 Impatience
3 Laziness
2 Hubris
3 Typhoid
4 Measle
1 Procrastination
[download]

Output:

1 Cold
1 Flu
1 Procrastination
2 Diabetics
2 Hubris
3 Laziness
3 Typhoid
4 Impatience
4 Measle
[download]

Hello,

The Perl hast How-To may be of use. A hash of arrays would solve the problem of having a hash of priorities with multiple diseases each having the same priority. But, an array of arrays would as well.

What's in the database? Knowing how that data is presented might be helpful.

EDIT:

I think I might have a better idea of what you're looking for. You could try something like this:

#!/usr/bin/perl -w
use strict;

my @diseases = ();

$diseases[0] = ['flu','cold'];
$diseases[1] = ['Diabetics'];
$diseases[2] = ['Typhoid'];
$diseases[3] = ['Measels'];

for(my $priority = 0;$priority < scalar(@diseases);$priority++){
    print "Priority $priority diseases:\n";
    foreach(@{$diseases[$priority]}){
        print "\t$_\n";
    }
}
[download]

Priority 0 diseases:
        flu
        cold
Priority 1 diseases:
        Diabetics
Priority 2 diseases:
        Typhoid
Priority 3 diseases:
        Measels
[download]

EDIT #2: Just noticed; you need to add 1 to $priority when printing to make it display properly, since your priority list starts with '1' and not '0'.

Hi, Thanks for your suggestion. But when printing the results from the database it prints in the same order as it fetches. Also, I have two sets of diseases. Say: disease_1:

1 flu
1 cold
2 measles
[download]


and another set of disease like:

1 diabetes
2 typhoid
[download]


Those two sets are distinguished based on the process they go for. there may be some disease which appears in both the sets.
The diseases are not the exact names but an example of it. The Query fetches different process that the disease has passed through. But I think that doesn't matter us much(!) here. The problem is I am having the same problem again that is ,the order of the disease is not in the order that I have got in the array but IT comes randomly as it fetches in the database. for example:


XXX:measles  45  35  67  1000
XXX:flu      67  35  45  7000
XXX:typhoid  56  78  89  1000
[download]


Note the XXX:disease is the way the disease is stored inthe database.
What I need to have is the exact order and priority number along with the exact names that I have stored in the array.
Thanks for your suggestions.

The sane approach would be to store the priority in the database with the rest of the information and obtain the list sorted by the priority.

If you can't do that, save the priorities in a hash, but reverse to what you show in your post:

%priority = (
  Flu => 1,
  Cold => 1,
...
[download]

I was doing that way before posting here and sorted that with the value: something like this:

foreach my $pri(sort {$prior{$a} <=> $prior{$b}} keys 
%prior)
 print $pri, $prior{$pri}, "\n";
[download]



where 'prior' is the hash and I had them getting sorted if I print them right after sorting. But after getting the data from the database I would like to get them in the same order as I have initialized them in the hash/array. My problem is to get them sorted in the net report I am going to print by the priority. Also, I have two different sets of disease with the same disease repeating in both the sets.

As in your suggestion, you mean @sorted as a new array which sorts by priority of the array obtained from the database? Could any one make me clear whether I have understand the point clearly?
once again,Thanks for your suggestions

Update: Sorry I tried through your suggestion and it gives an error message with


Can't use string ("XXXX2: Multiple sclerosis") as an ARRAY ref while "
+strict refs" in use at dna_reportertest line 139
[download]

I cant really understand why is that so.. when it goes through all the other disease (nearly 5 before)? Any comments? Thanks

Simply strech the priority numbers so that no collisions exist anymore, so Flu=> 1, Cold => 2, Diabetes =>3.... If nobody told you in which order the Flu and Cold records should be printed, they might as well be printed ordered. Then you can simply store the names in an array and loop through the array

If the method above is not possible: Store the names in an array, but because of the collisions either use an Array of Arrays, or, if you are uncomfortable with that, concatenate names with equal priority : "Flu,Cold". The concatenated values can be extracted again with split