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Search Hash of Arrays - using Grep



sriharsha_12
Novice

Sep 25, 2013, 12:37 AM


Views: 2834
Search Hash of Arrays - using Grep
Say I've a hash (hash of arrays),
Code
%hashSample = 
( 
   1 => ["AB, "XY"], 
   2 => ["BC, "YZ"], 
   3 => ["CA, "ZX"] 
);
I need the find the key for value "AB". How do I do that using grep in PERL?


BillKSmith
Veteran

Sep 25, 2013, 10:14 AM


Views: 2823
Re: [sriharsha_12] Search Hash of Arrays - using Grep
It requires nested greps.
Code
use strict; 
use warnings; 
my %hashSample = ( 
    1 => ["AB", "XY"], 
    2 => ["BC", "YZ"], 
    3 => ["CA", "ZX"], 
    ); 
 
(my $hashkey) = grep { 
    grep {$_ eq 'AB'} @{$hashSample{$_}}} 
        keys %hashSample;     
 print $hashkey, "\n";
Note: The outer grep must be in list context even if you only want one key. If there is more than one match, this code will return the first of them.
Good Luck,
Bill


sriharsha_12
Novice

Sep 25, 2013, 11:38 PM


Views: 2812
Re: [BillKSmith] Search Hash of Arrays - using Grep
Thanx Bill. It works perfect.