...Each “day” introduces a coding problem, concept, or mini project that builds on previous days: for example, fundamentals on day 1, optionals and control flow, Swift data structures, closures, protocol programming, UI interaction, etc., culminating in more advanced topics or sample apps. Solutions, hints, or sample projects accompany many of the prompts, allowing learners to compare approaches or download runnable code. The challenge format gives structure and pacing, helping learners stay motivated and consistent. Because the repo is public, contributors can add new challenge ideas, alternative solutions, or refinements as Swift evolves.