Do you all know of a good place I can study or learn about these short/compact functions? Is it called perl golf? What is perl golf?

Re^3: Golf code in perl (Context)

And no, please don't use "golfed" code for any other purpose than to play golf. It's simply unmaintainable in that form, write-only code in its purest form. Prefer writing longer, readable code that you (or any other maintainer) will still understand in half a year, a year, or five years. If you resort to "dirty tricks" (like string xor plus counting NUL bytes), add a comment that explains how the trick works and the requirements for that trick (e.g. strings must only contain ACGT, all upper case, both the same length, etc). Don't make your future self invent a time machine to come back and severely hurt you for the mess you will have written.

Alexander