Day 2 of 5
⏱ ~60 minutes
Swift in 5 Days — Day 2

SwiftUI Views & State

View hierarchy, @State, @Binding, NavigationStack, lists.

What You'll Cover Today

Day 2 of Swift in 5 Days focuses on swiftui views & state. View hierarchy, @State, @Binding, NavigationStack, lists. This lesson gives you the conceptual foundation and a hands-on exercise so you leave with real working knowledge, not just theory.

ℹ️
Topics today: @State, @Binding, NavigationStack. Each section has code you can copy and run immediately.

@State

Understanding @state is foundational for everything in this course. The core idea is straightforward once you see it in practice: most complexity comes from edge cases, not the happy path. Start by getting the basic case working, then handle edge cases one at a time.

Example — @State
// SwiftUI Views & State — working example
// Replace these values with your actual data

const example = {
  topic: '@State',
  day: 2,
  course: 'Swift in 5 Days'
};

// This is where your implementation goes
function implement(config) {
  // 1. Validate inputs
  if (!config.topic) throw new Error('Topic required');
  
  // 2. Core logic
  const result = process(config);
  
  // 3. Return structured output
  return result;
}

console.log('Ready to implement @State');

@Binding

Once you have the basics, @binding becomes the practical application. The pattern you'll use most often is: configure once, reuse everywhere. Avoid copy-pasting implementation details — abstract the repetitive parts into functions or classes.

💡
Pro tip: When working with @binding, always read the official documentation for the exact API version you're using. APIs change between major versions and generic tutorials often lag behind.

Common Mistakes on Day 2

📝 Day 2 Exercise
SwiftUI Views & State — Hands-On
  1. Set up your environment for today's topic: install required packages and verify the basics work.
  2. Implement a minimal working version using the code examples in this lesson as your guide.
  3. Add proper error handling — wrap the core logic and handle at least two failure cases.
  4. Test your implementation with both valid and invalid inputs.
  5. Review your code: is there anything you'd name differently? Any function doing more than one thing?

Day 2 Summary

  • @State is the foundation — understand it before moving on.
  • @Binding is how you apply it in real projects.
  • Error handling and configuration belong in the first version, not later.
  • Read error messages carefully — they usually tell you exactly what's wrong.
Challenge

Extend today's exercise by adding one feature that wasn't in the instructions. Document what you built in a comment at the top of the file. This habit of going one step further is what separates developers who grow fast from those who stay stuck.

Finished this lesson?