How can I print hash values when the keys are the values from another hash.

boat73 has asked for the wisdom of the Perl Monks concerning the following question:

Hello wise ones I have two hashes, hashA and hashB. The values in hashA are the keys in hashB. I want to loop through hashA and print all of the values in hashB. The following code is what I expected to work, but it doesn't. Could anyone smarter than me tell me why? Thanks in advance.

    while (($key, $value) = each(%hashA)){
        print "$key = ".$hashB{$hashA{"${value}"}}."\n";
    }
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Comment on How can I print hash values when the keys are the values from another hash. Download Code

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Re: How can I print hash values when the keys are the values from another hash. by ikegami (Patriarch) on Apr 06, 2006 at 17:31 UTC
First, let's get rid of an abomination. Change `"${value}"` to `$value` The values in hashA are the keys in hashB. `$value` contains a value from hashA. Just use `$value` as the key to hashB. Change `$hashB{$hashA{$value}}` to `$hashB{$value}` Maybe you were thinking of `$hashB{$hashA{$key}}` which also works.	[reply] [d/l] [select]
Re: How can I print hash values when the keys are the values from another hash. by ptum (Priest) on Apr 06, 2006 at 17:31 UTC
How about something like this (untested): `foreach (keys %hashA) { print "$_ = $hashB{$hashA{$_}} \n"; }` [download] No good deed goes unpunished. -- (attributed to) Oscar Wilde	[reply] [d/l]
Re: How can I print hash values when the keys are the values from another hash. by davido (Cardinal) on Apr 06, 2006 at 19:10 UTC
How about this?: `my %hashA = ( this => 'A', that => 'B', other => 'C' ); my %hashB = ( A => 'aye', B => 'bee', C => 'see' ); { local $" = "\n"; print "@hashB{ values( %hashA ) }\n"; }` [download] Dave	[reply] [d/l]
Re: How can I print hash values when the keys are the values from another hash. by TedPride (Priest) on Apr 06, 2006 at 19:51 UTC
`print "$_ = $hashB{$_}\n" for sort keys %hashA;`	[reply] [d/l]