Re: Ignore Case when comparing Hash Keys

When you transform the keys to lowercase for a case-insensitive lookup, keep the old name around for printing later.

#! /usr/bin/perl

%hash1 = ("John", 43, "Paul", 25, "Marie", 22);
%hash2 = ("john", 43, "Paul", 25, "marie", 22); 

my %lc_hash1 = map { lc $_ => { name => $_,
                                value => $hash1{$_} } 
                   } keys %hash1;

while (($KEY_2, $VALUE_2) = each %hash2){
    if (exists $lc_hash1{lc $KEY_2}){
         print "$KEY_2 : Matched\n";
    }
    else{
         print "$KEY_2 : Did not match\n";
    }
}
[download]

Now you can use $lc_hash1{$SOMEKEY}{name} for the original key and $lc_hash1{$SOMEKEY}{value} for the value.

Comment on Re: Ignore Case when comparing Hash Keys Download Code

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Re^2: Ignore Case when comparing Hash Keys by ctilmes (Vicar) on Nov 15, 2010 at 19:21 UTC
Or just store the original key as the value of the canonicalized (lower-cased) hash. Look up in the lower case hash to find the key, then use the value of that hash to look up the value in the original hash. `#! /usr/bin/perl %hash1 = ("John", 43, "Paul", 25, "Marie", 22); %hash2 = ("john", 43, "Paul", 25, "marie", 22); my %lc_hash1 = map { lc $_ => $_ } keys %hash1; while (($KEY_2, $VALUE_2) = each %hash2){ if (exists $lc_hash1{lc $KEY_2}){ print "$KEY_2 : Matched\n"; print "Keys are: $lc_hash1{lc $KEY_2}, $KEY_2\n"; print "Values are: $hash1{$lc_hash1{lc $KEY_2}}, $VALUE_2\n"; } else{ print "$KEY_2 : Did not match\n"; } }` [download]	[reply] [d/l]
Re^3: Ignore Case when comparing Hash Keys by avidcoder (Novice) on Nov 15, 2010 at 19:56 UTC
ctilmes --- Thanks a lot. This works great!!! Just the way I want it to. You saved me a ton of time. Thankyou all.	[reply]


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