multidimensional hash of array

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

<HTML> How can I create a hash with 2 key value pairs that also links to an array of data?
I am not sure if this is called a multidimensional hash of arrays.
Upon reading a file I need to compare 2 vaules for example Network and connection type.
If these values do not exist create the new values and store the trailing data with them.
I currently have the following which works with only one key pair, but it is over writing the
previous data because I am only comparing one field:

@str = qw( 7 house network_name 4 6); //<--example of data

if($myhash {$str2}}){  
  // if netowrk_name is found increment the values of 3 and 4 
} 

else{ 

//must be new so ad new data to hash 

}
[download]

But I need to compare and store 2 results.
example I need to store and compare 0 and 2 and then have that array of data behind it.
Can someone shed some light on this for me?
thanks, Kev
kev@kevintaylor.net </HTML>

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Re: multidimensional hash of array by davorg (Chancellor) on May 31, 2001 at 19:18 UTC
You can get a lot of good advice on complex data structures by reading `perldoc perlreftut` and `perldoc perldsc`. Here are some clues: `@str = qw( 7 house network_name 4 6); #<--example of data if ($myhash{$str[2]}{$str[0]){ # if network_name is found increment the values of 3 and 4 ($myhash{$str[2]}{$str[0]}[3])++; ($myhash{$str[2]}{$str[0]}[4])++; } else { # must be new so ad new data to hash $myhash{$str[2]}{$str[0]} = [ @str ]; }` [download] -- <http://www.dave.org.uk> "Perl makes the fun jobs fun and the boring jobs bearable" - me	[reply] [d/l]
Re: multidimensional hash of array by bwana147 (Pilgrim) on May 31, 2001 at 20:06 UTC
A simple solution is two concatenate the two keys into one with a seldom used character. In fact, that's what Perl does internally when you give several keys to index a hash: `$myhash{'key1', 'key2'};` is equivalent to: `$myhash{join("\x1c", 'key1', 'key2')};` ASCII 28 is considered a seldom used character, but you may use another one by changing `$;`. Needless to say this is widely considered dirty. davorg's suggestion of using a hash of hashes of arrays is a lot neater. HTH --bwana147	[reply] [d/l] [select]
Re: Re: multidimensional hash of array by kevyt (Scribe) on May 31, 2001 at 20:26 UTC
I would like to thank everyone for their help I currently have: foreach(@info){ $_=~ s/^\s+//; @str = split; if( $myhash{$str[2]}{$str[0]} ){ # if same connection type al +ready stored ( $myhash{$str[2]}{$str[0]}[0] ) += $str[0]; ( $myhash{$str[2]}{$str[0]}[1] ) += $str[4]; ( $myhash{$str[2]}{$str[0]}[2] ) += $str[5]; ( $myhash{$str[2]}{$str[0]}[3] ) += $str[6]; ( $myhash{$str[2]}{$str[0]}[4] ) += $str[7]; ( $myhash{$str[2]}{$str[0]}[5] ) += $str[8]; ( $myhash{$str[2]}{$str[0]}[6] ) += $str[9]; ( $myhash{$str[2]}{$str[0]}[7] ) += $str[12]; ( $myhash{$str[2]}{$str[0]}[8] ) += $str[13]; ( $myhash{$str[2]}{$str[0]}[9] ) += $str[16]; } else{# if connection type is not stored push(@temp, $str[0], $str[4], $str[5], $str[6], $str[7], +$str[8], $str[9], $str[12], $str[13], $str[16]); $myhash{$str[2]}{$str[0]} = [@temp]; #enter new data } } [download] My next step will be determining how to print, I was using the code below but I will change that `foreach my $element(sort keys %myhash){ printf OUT ("%-20s", $element); foreach (@{$myhash{$element}}){ printf OUT ("%8s", $_); } print OUT "\n"; }#foreach` [download] thanks everyone	[reply] [d/l] [select]