See perlintro or perldata for a description of hashes. "key" and "value" are terms used together with hashes.

If you search for join files or similar keywords, you'll find quite a bit of example code, for example join mutiple files on first column and join - join two files according to a common key.

Perl 6 - the future is here, just unevenly distributed

In reply to Re^3: Compare 2 CSV files and create a new CSV file out of comparision by moritz
in thread Compare 2 CSV files and create a new CSV file out of comparision by slayedbylucifer

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