Classes and Instances

Classes and Instances

In this lesson — part of Objects and Classes — you'll learn classes and instances in Objective-C and why it matters in real work.

Why it matters

Classes bundle data and behavior together — the core of object-oriented design.

Key ideas

• Classes and instances
• Fields and methods
• Constructors
• Encapsulation

In practice

Here's the idea in pseudocode — the exact syntax varies by language:

// Objective-C: a class
class Counter {
  count = 0
  inc() { this.count += 1 }
}

Try it yourself

Exercise: In Objective-C, write a Bank Account class with deposit and withdraw methods.

Recap

You now understand classes and instances and can apply it in Objective-C. Mark this lesson complete and continue to the next one.