Sort Multidimensional Hash By Column

Here's a quick little subroutine that I wrote awhile back that I use a fair amount. It will sort a multidimensional hash by the value of whatever "column" you specify and throw the sorted keys back to you.

BTW, I sometimes use this more than once in a script to filter results down...that is why I pass an array ref as the last arg (so I can filter if need be).

Was able to remove the temp hash based on what Juerd wrote...Could have sworn I tried formatting the compare that way.

$hash{'1'}->{"person"} = "Me";
$hash{'1'}->{"age"} = "27";
$hash{'2'}->{"person"} = "Wife";
$hash{'2'}->{"age"} = "26";
$hash{'3'}->{"person"} = "Dad";
$hash{'3'}->{"age"} = "54";
$hash{'4'}->{"person"} = "Brother";
$hash{'4'}->{"age"} = "24";


my @sortedKeys = sortHashByColumn(\%hash,"age","desc",[keys %hash]);
        
foreach my $sortedKey(@sortedKeys){
    print "$sortedKey: " . $hash{$sortedKey}->{'age'} . " " . $hash{$s
+ortedKey}->{'person'} . "\n";
}





sub sortHashByColumn{
    my($hashRef,$sortColumn,$sortDirection,$keysAR) = @_;
    my @sortedKeys;
    my $sortType;
    # VERIFY THAT THIS IS A VALID COLUMN
    if(! defined $hashRef->{$$keysAR[0]}->{$sortColumn}){
        print "sortHashByColumn Error: $sortColumn is not a column in 
+this hash.\n";
        exit(0);
    # VALID COLUMN, FIGURE OUT IF IT IS A NUMERIC COLUMN OR ALPHA
    } else {
        if($hashRef->{$$keysAR[0]}->{$sortColumn} =~ /^\d+/){
            $sortType = "numeric";
        } else {
            $sortType = "alpha";
        }
    }
    
    if($sortType eq "numeric"){
        if($sortDirection =~ /asc/i){
            @sortedKeys = sort { $hashRef->{$a}{$sortColumn} <=> $hash
+Ref->{$b}{$sortColumn} } @$keysAR;
        } else {
            @sortedKeys = sort { $hashRef->{$b}{$sortColumn} <=> $hash
+Ref->{$a}{$sortColumn} } @$keysAR;
        }
    } else {
        if($sortDirection =~ /asc/i){
            @sortedKeys = sort { $hashRef->{$a}{$sortColumn} cmp $hash
+Ref->{$b}{$sortColumn} } @$keysAR;
        } else {
            @sortedKeys = sort { $hashRef->{$b}{$sortColumn} cmp $hash
+Ref->{$a}{$sortColumn} } @$keysAR;
        }
    }


    return @sortedKeys;
}
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Comment on Sort Multidimensional Hash By Column Download Code

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Re: Sort Multidimensional Hash By Column by Juerd (Abbot) on Dec 20, 2001 at 03:08 UTC
I'd never create a sub for that. `%h = ( pizza => { foo => 14, bar => 29 }, shoarma => { foo => 2, bar => 53 }, gyros => { foo => 10, bar => 35 }, ); @keys_sorted_foo_ascn = sort { $h{$a}{foo} <=> $h{$b}{foo} } keys %h; @keys_sorted_foo_desc = sort { $h{$b}{foo} <=> $h{$a}{foo} } keys %h; @keys_sorted_bar_ascn = sort { $h{$a}{bar} <=> $h{$b}{bar} } keys %h; @keys_sorted_bar_desc = sort { $h{$b}{bar} <=> $h{$a}{bar} } keys %h;` [download] I find this a LOT easier than using a sub. `2;0 juerd@ouranos:~$ perl -e'undef christmas' Segmentation fault 2;139 juerd@ouranos:~$` [download]	[reply] [d/l] [select]

Replies are listed 'Best First'.

Re: Sort Multidimensional Hash By Column
by Juerd (Abbot) on Dec 20, 2001 at 03:08 UTC

%h = (
 pizza   => { foo => 14, bar => 29 },
 shoarma => { foo =>  2, bar => 53 },
 gyros   => { foo => 10, bar => 35 },
);

@keys_sorted_foo_ascn = sort { $h{$a}{foo} <=> $h{$b}{foo} } keys %h;
@keys_sorted_foo_desc = sort { $h{$b}{foo} <=> $h{$a}{foo} } keys %h;
@keys_sorted_bar_ascn = sort { $h{$a}{bar} <=> $h{$b}{bar} } keys %h;
@keys_sorted_bar_desc = sort { $h{$b}{bar} <=> $h{$a}{bar} } keys %h;
[download]

2;0 juerd@ouranos:~$ perl -e'undef christmas'
Segmentation fault
2;139 juerd@ouranos:~$
[download]

[reply]
[d/l]
[select]