Truthiness & Guard Clauses

Quick recap: only two falsy values

Back in module 01 you met Ruby's falsy trap: only nil and false are falsy. 0, "", and empty arrays are all truthy — the opposite of JS and Python. That one fact is why the idioms in this lesson read as clean as they do: a bare if booking genuinely means "booking is not nil and not false," nothing fuzzier.

This module is the last stop before Rails. Everything here is about reading real Ruby comfortably — the small idioms that show up in almost every method you'll open in apps/pawwalk-api.