Rajiv has asked for the wisdom of the Perl Monks concerning the following question: ⭐ (hashes)

Perl Monks, Please Suggest: How can i find whether two hash tables have same and equal number of keys.

Originally posted as a Categorized Question.

  • Comment on How to check similarity of two hash tables

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Re: How to check similarity of two hash tables⭐
by RMGir (Prior) on Apr 09, 2002 at 14:21 UTC
    Of course, the obligatory one-liner (ok, one-expression) version: 
    my $areEqual = (keys %hash1 == keys %hash2)
     && 0 == grep {!exists $hash2{$_}} keys %hash1;

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Re: How to check similarity of two hash tables
by RMGir (Prior) on Apr 09, 2002 at 14:11 UTC
    They're equal if, as you say, they have the same number of keys AND all the keys in one are in the other. 
    my $areEqual=1;

if(keys %hash1 == keys %hash2) {
    foreach my $key(keys %hash1) {
        if(!exists $hash2{$key}) {
             $areEqual=0;
             last;
        }
    }
}

if($areEqual) {
    print "ARE ";
} 
else {
    print "ARE NOT ";
}

print "equal\n";

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