http://www.perlmonks.org?node_id=267583


in reply to adding key/value pairs to a hash.

$key = 'd';
$value = 4;
$hash{$key} = $value;

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That's all you need to do.
Update:
Just wanted to say that hashes can be used for so many different things, internal (e.g. %ENV, %INC, %main) and external, in perl; you will want to master them. If you're not getting enough from the 'camel' book, try the Black Book and perldoc -q hash.

In Section Seekers of Perl Wisdom