In a hash a key-value pair have 3 different possible statuses.
The defined function checks if a value is undef or not.
The exists function check if a key is in the hash or not.
Those two conditions create 3 valid situations.
Perl Maven Pro - screencasts with articles
As a Perl Maven Pro subscriber you will enjoy a growing library of articles and screencasts.
Two screencasts a week and all the previous screencasts!
Ad free browsing!
The articles contain topics such as Web Application Development, Object Oriented programming, testing, deployment, code walkthroughs, best practices, and many more subjects in Perl, and in related technologies.
Subscriptions include all previous pro episodes.
If you already have Perl Maven Pro subscription, you will need to login to access the articles.