You seem to pose a new and usually very basic question so ofter that the pace that suggests you haven't (and are not) studying Perl in any systematic (nor much of any other) manner.

And one wonders (well, /me wonders) if you learned anything from answers to one of your questionsw yesterday, Dereferencing array of hashes. It's really not a stretch to read the replies, understand them and the references they offer, and to have thus avoided this thread.

Try reading "Learning Perl" ( less than USD 2.00 )and the Tutorials here before asking others how to resolve each little glitch in your (minimal) effort to write the code needed to complete a project.

Surely, you've seen some of the responses to "gimme'" nodes that point out that the Monastery is an institution which aims to help you learn; NOT one that writes your code for you.