Re: Comparing two hashes for duplicate keys with no case sensitivity

Hi, Anonymous -

I understand you want to check case-insensitively which keys in hash2 are also keys of hash1. The following solution might be a good option for large hashes as it only involves one loop:

my $string = join " ", keys %hash1;

foreach my $item ( keys( %hash2 ) ) 
{
     print "$item matches" if ( $string =~ /\b$item\b/i );
}
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Re^2: Comparing two hashes for duplicate keys with no case sensitivity by chromatic (Archbishop) on Aug 15, 2008 at 01:07 UTC
That's clever, but I count two loops (and you should probably use `\Q...\E` as well).	[reply] [d/l]
Re^3: Comparing two hashes for duplicate keys with no case sensitivity by pat_mc (Pilgrim) on Aug 15, 2008 at 16:36 UTC
Hm ... where is the second loop you're seeing, chromatic? Is the `join` operator an undercover loop as well? Clearly, if the complexity of the `join` operation is equivalent to that of a regular `for` loop we don't gain much. Cheers - Pat	[reply] [d/l] [select]
Re^4: Comparing two hashes for duplicate keys with no case sensitivity by chromatic (Archbishop) on Aug 15, 2008 at 17:08 UTC
Yes, join is `O(n)` where n in this code is the number of keys in the hash. Perl's implementation is slightly more efficient for join than Perl-side iteration, but that's why there's a join operator.	[reply] [d/l]