It’s also sometimes very useful to use Data::Dumper to display for you exactly what a data-structure actually looks like.   Although the “actual” world of Perl only contains lists, arrays, and so-on, the presence of “references” (and a very-generous syntax which assumes you know what you want and which gives you more-than-one way to say it) can make it hard to visualize what you’re actually looking-at and/or what you’re actually going to get.   The Dumper is a good tool for, “show me...”