Swift for Complete Beginners (Paul Hudson)

Paul Hudson's 'Swift for Complete Beginners', 71 short lessons and about 9 hours, the language foundation for iOS and SwiftUI development. It covers constants and variables, strings, integers, decimals and Booleans, then arrays, dictionaries, sets, enums and type annotations, conditions, switch, the ternary operator, for and while loops, functions with return values, labels, defaults and error handling, closures and trailing closures. Later lessons build structs with computed properties, observers, initializers, access control and static members, then classes, inheritance, deinitializers, protocols, opaque return types, extensions and protocol extensions, and optionals with guard, nil coalescing and optional chaining. Each section ends with a summary and a checkpoint exercise.