Lesson 7: Swift setup and first program: Performance perspective

Concept Explanation

"Swift setup and first program: Performance perspective" is a standalone Beginner Swift lesson that helps you think about performance while keeping your code clear and correct. You will work through a practical coding task, compare a couple of approaches, and pay attention to how small design choices affect efficiency and maintainability. The lesson focuses on the Beginner Swift skill of performance perspective in Swift setup and first program. As you move through the exercise, you will practice Swift patterns that commonly appear in iOS and macOS development while applying safe optionals, clear APIs, and maintainable app architecture. Lesson fingerprint: swift:Swift Beginner:Swift setup and first program:beginner-swift-setup-and-first-program-7:7.

Where to Put the Code

1. Define color and position variables at the top.
2. Create shape drawing or placement logic in the middle.
3. Render output (print, canvas, SVG, or styled block) at the end.

Command Reference

• Refactor once using safe optionals, clear APIs, and maintainable app architecture.
• Check the result and record the expected behavior.
• Modify the baseline implementation once and compare the outcome.
• Create a quick test input set for lesson unit 7.

Step-by-step Guide

1. Write a brief note explaining what changed and why.
2. Test one normal case and one edge case.
3. Compare two implementations and choose one with a clear reason.
4. Finish with a short checklist for correctness and clarity.
5. Make one focused change to the baseline implementation and compare the result.

Practice Exercises

• Rewrite the logic in a cleaner style without changing the result.
• Add one more scenario that stresses an edge case.
• Add validation rules and explain three design decisions.

Coding Challenges

• Apply one quality rule based on safe optionals, clear APIs, and maintainable app architecture across all code blocks.
• Implement two versions and compare their maintainability and complexity.

Mini Practice Tasks

• Rename variables or functions to make their purpose clearer.
• Add one meaningful improvement and run the checks again.
• Create a shorter version of the solution for lesson unit 7.