How to use hash functions when Perl scripting

This Perl Tutorial series shows you how to use has functions including:
1.)The exists, defined and delete functions.
2.)How to reverse the key/value pairs of a hash, sort hashes and merge hashes.
3.)The split and join functions.
4.)The lc, uc, lcfirst, ucfirst functions and a method to ucfirst every word in a string.
5.)The length, substr, index and rindex functions .