Interfaces

1. Welcome and Icebreaker:

• If you could define a contract for your ideal job, what would be required and what would be optional?

2. Outline the Session:

• We’ll learn about interfaces in TypeScript: how to define contracts for classes and objects.
• Learning Outcomes: Understand how interfaces enforce structure and how to implement them.
• Let’s get structured!

3. Concept Explanation:

• Interfaces define the shape of objects and contracts for classes.
• Classes and objects that implement an interface must have all its properties and methods.
• Interfaces can extend other interfaces.
• Use implements to make a class follow an interface.

4. Live Coding Demonstration:

interface Logger {
  log(message: string): void;
}

class ConsoleLogger implements Logger {
  log(message: string): void {
    console.log(`LOG: ${message}`);
  }
}

const logger = new ConsoleLogger();
logger.log("Hello, interface!");

// Interface for objects
interface Point {
  x: number;
  y: number;
}

const pt: Point = { x: 10, y: 20 };
console.log(pt);

5. Tasks:

• Short Exercise:
  1. Define an interface Vehicle with properties: make (string), model (string), and a method drive().
  2. Create a class Truck that implements Vehicle.
  3. Create an instance of Truck and call its drive() method.