Sort and Print Hashes simultaneously

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

I used the following code to check the hash keys in 2 hashes and print the same occurring hash key and its respective value

while (((my $key1,my $value1)=each(%websites)))
{
    while (((my $key2,my $value2)=each(%newsites)))
    {
        if($key1 = $key2)
        {
            print "$key2=$value2 \n";
        }
    }
}
[download]

But, i want to sort the hash keys numerically in both the hash tables and then print the common key and the value . So how can i sort and print it simultaneously

Comment on Sort and Print Hashes simultaneously Download Code

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Re: Sort and Print Hashes simultaneously by moritz (Cardinal) on Nov 01, 2010 at 16:42 UTC
Doing linear scans over an associative array is like trying to club someone to death with a loaded Uzi. -- TimToady `for my $key (sort { $a <=> $b } keys %websites) { if (exists $newsites{$key}) { print "$key=$newsites{$key}\n"; } }` [download] See also: sort, keys, exists, perlfaq4. Perl 6 - links to (nearly) everything that is Perl 6.	[reply] [d/l]
Re^2: Sort and Print Hashes simultaneously by sundeep (Acolyte) on Nov 01, 2010 at 16:49 UTC
Thanks a lot... I really don't know that, i can do it without a linear search. Anyways, i am learning a lot from u guys.... thanks for the immediate reply....	[reply]
Re: Sort and Print Hashes simultaneously by kennethk (Abbot) on Nov 01, 2010 at 16:47 UTC
First, `$key1 = $key2` is an assignment, not a logical test (==) -- see perlop. This will return true provided the value in `$key2` evaluates to true. warnings would have issued a warning if you'd tested your code before posting. See How do I post a question effectively?. You need only loop over one hash - you can easily test if that key is present in the second hash by accessing it as a hash. You can sort the keys in the loop declaration. `for my $key (sort { $a <=> $b } keys %websites) { if (exists $newsites{$key1}) { print "$key=$newsites{$key1}\n"; } }` [download] Most of this is discussed in the Data: Hashes (Associative Arrays) section of perlfaq4.	[reply] [d/l] [select]