Re: Printing a Hash Slice problem

this should do the trick:

use strict;
use warnings;

my $HoA_ref = {'GAT' => [2, ['ttt',-3,1],['ttc',-3,3],['ccc',-1,2]],
               'AAA' => [13,['aaa',-1,2],['atg',-2,2]],
               'TTT' => [11,['tta',-2,1],['atc',-3,3]]
               };


sub print_zHoA {
    my ($HoA) = shift;
    my $mc = (sort {$$HoA{$a}[0] <=> $$HoA{$b}[0]} keys %$HoA)[-1];
    print "$mc $$HoA{$mc}[0]:\n";
    for my $i ( 1 .. $#{$$HoA{$mc}} ) {
        print join( ',', @{$$HoA{$mc}[$i]} ), "\n";
    }
}


print_zHoA($HoA_ref);
[download]

Comment on Re: Printing a Hash Slice problem Download Code

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Re^2: Printing a Hash Slice problem by monkfan (Curate) on Mar 02, 2005 at 07:28 UTC
Dear Taumarill, Thanks for answering. Just a question regarding your code above: `my $mc = (sort {$$HoA{$a}[0] <=> $$HoA{$b}[0]} keys %$HoA)[-1];` [download] 1. What does '-1' means here? 2. Why '=' sign? Basically what does the statement above means? How does it work? Regards, Edward	[reply] [d/l]
Re^3: Printing a Hash Slice problem by jhourcle (Prior) on Mar 03, 2005 at 01:18 UTC
`[-1]` is a negative array index, which lets you count from the other end of an array. `$array[-1]` is the same as `[reverse @array]->[0]` or `$array[$#array]` `<=>` is a comparison operator for numbers, similar to `cmp` for strings. (see perlop or the sort documentation)	[reply] [d/l] [select]