Inheritance

1. Welcome and Icebreaker:

• If you could inherit any skill or trait from someone, what would it be?

2. Outline the Session:

• We’ll learn about inheritance in TypeScript: how classes can extend other classes and override methods.
• Learning Outcomes: Understand how to use inheritance to reuse and extend functionality.
• Let’s build on what we know!

3. Concept Explanation:

• Inheritance allows a class (child/subclass) to inherit properties and methods from another class (parent/superclass).
• Use the extends keyword to create a subclass.
• Subclasses can override methods from the parent class.
• Use super() to call the parent class constructor or methods.

4. Live Coding Demonstration:

class Vehicle {
  make: string;
  constructor(make: string) {
    this.make = make;
  }
  drive() {
    console.log(`${this.make} is driving.`);
  }
}

class Car extends Vehicle {
  model: string;
  constructor(make: string, model: string) {
    super(make);
    this.model = model;
  }
  drive() {
    console.log(`${this.make} ${this.model} is zooming!`);
  }
}

const myCar = new Car("Toyota", "Corolla");
myCar.drive(); // Toyota Corolla is zooming!

5. Tasks:

• Short Exercise:
  1. Create a class Employee with properties: name (string) and salary (number).
  2. Create a subclass Manager that adds a property department (string) and overrides a method to print a custom message.
  3. Create an instance of Manager and call its method.