accessing hash of arrays

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

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Re: accessing hash of arrays by arun_kom (Monk) on Aug 21, 2009 at 07:26 UTC
If you can store the values of the hash in a list, then you can access its elements by their indices. `my %hash = ( 4 => [10, "mango"] , 2 => [04, "banana"] , 3 => [20, "apple"], ); foreach (keys %hash){ print "$_: $hash{$_}[0]\n"; }` [download]	[reply] [d/l]
Re^2: accessing hash of arrays by tmharish (Friar) on Aug 21, 2009 at 07:52 UTC
Ya! ... My mistake.	[reply]
Re: accessing hash of arrays by jwkrahn (Abbot) on Aug 21, 2009 at 07:30 UTC
`$ perl -le' my %hash = ( 4 => [ 10, "mango" ], 2 => [ 04, "banana" ], 3 => [ 20, " +apple" ] ); for my $array ( values %hash ) { print $array->[ 0 ]; } ' 10 20 4` [download]	[reply] [d/l]
Re^2: accessing hash of arrays by Anonymous Monk on Aug 21, 2009 at 07:39 UTC
I understood. we can print that by loop. But I want to access like an array. I wanted to sort those numbers. For this I can store all these numbers and I can pass. But I want to pass all those numbers to sort without storing.	[reply]
Re^3: accessing hash of arrays by rovf (Priest) on Aug 21, 2009 at 08:20 UTC
my %hash = ( 4 => 10, "mango" , 2 => 04, "banana" , 3 => 20, "apple" ); You use values to turn your hash into an array of array references. Then you use map to turn this array into an list of the numbers. Finally you use sort to sort that list. -- Ronald Fischer <ynnor@mm.st>	[reply] [d/l]
Re: accessing hash of arrays by tmharish (Friar) on Aug 21, 2009 at 07:22 UTC
Your hash structure does not look too clear to me. But from what I understand it should be: `%hash = ( 4 => \( 4, 'mango' ) ... )` [download] If this is indeed the structure you can access 10,04, ... as follows: `@{ $hash[4] }[0] will give 10 @{ $hash[4] }[1] will give Mango @{ $hash[2] }[0] will give 04 @{ $hash[3] }[0] will give 20 and so on ...` [download] If you can tell us how you initialized your Hash, maybe things could be clearer.	[reply] [d/l] [select]
Re^2: accessing hash of arrays by rovf (Priest) on Aug 21, 2009 at 07:26 UTC
4 => \( 4, 'mango' ) I guess you mean `4 => [4, 'mango']` [download] ? -- Ronald Fischer <ynnor@mm.st>	[reply] [d/l]
Re: accessing hash of arrays by sanku (Beadle) on Aug 21, 2009 at 09:49 UTC
hi, You can able to get the values of 10,04,20 by using the following code. But before that one more thing is you have to mention the hash as we have declared in the below code i mean u have to mention the each and every hash element values as anonymous array. `my %hash = ( 4 => [10, "mango"] , 2 => [04, "banana"] , 3 => [20, " +apple"] ); while(($key,$value) = each (%hash)){ print @$value[0]; }` [download]	[reply] [d/l]
Re: accessing hash of arrays by AnomalousMonk (Archbishop) on Aug 21, 2009 at 16:54 UTC
Pitfall Alert: The notation `04` in the example code in the OP will be evaluated as an octal number! Consider: `>perl -wMstrict -le "my $s; $s = 04; print $s; $s = 011; print $s; " 4 9` [download]	[reply] [d/l] [select]
Re: accessing hash of arrays by bichonfrise74 (Vicar) on Aug 21, 2009 at 16:15 UTC
There are more than one way to do this. `#!/usr/bin/perl use strict; my %hash = ( 4 => [10, "mango"] , 2 => [04, "banana"] , 3 => [20, "apple"], ); for my $i ( keys %hash ) { print "$i: $hash{$i}->[0]\n"; }` [download]	[reply] [d/l]