Adaptive skill practice — find your level, get sharper.
Swift practice
Optionals, protocols, ARC, and concurrency
The Swift language in depth, from the official language guide. Optionals and the unwrapping toolkit (if let, guard let, chaining — and why force-unwrap crashes), value versus reference semantics (structs vs classes, copy-on-write), properties and observers, closures and capture semantics (escaping, capture lists and retain cycles), protocols and protocol-oriented design, generics and associated types, enums with associated values, error handling (throws, try/try?/try!, Result), memory management (ARC, weak vs unowned), and modern concurrency (async/await, actors, tasks). Heavy on predict-the-output and spot-the-bug items so understanding is tested, not vocabulary. Every explanation names the principle, the trap, and a rule you code by. Authored from the official Swift documentation at its current stable release.
• Meets you at your level — never too easy, never too hard.
• Adapts every question to how you’re doing.
• Tracks your level over time. Skill practice, not a test.
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