Lära Method Overriding and super | Inheritance and Class Hierarchies


              123456789101112131415161718
            
class Animal {
  makeSound() {
    console.log("Some generic animal sound");
  }
}

class Dog extends Animal {
  makeSound() {
    super.makeSound();
    console.log("Woof!");
  }
}

const myDog = new Dog();
myDog.makeSound();
// Output:
// Some generic animal sound
// Woof!

When you create a derived class in TypeScript, you can override methods from the base class to change or extend their behavior. This is called method overriding. To override a method, you simply define a method with the same name in the derived class. If you want to use the original implementation from the base class as part of your new method, you can call it using the super keyword. The super keyword refers to the parent class and allows you to access its methods or constructor.

By calling super.methodName(), you can invoke the base class version of a method before or after adding extra logic in your derived class. This is especially useful when you want to extend the functionality rather than completely replace it. Overriding methods and using super helps you build flexible and maintainable class hierarchies, where shared behavior is defined once in a base class, and specialized behavior is added in derived classes.

Var allt tydligt?

Tack för dina kommentarer!

Avsnitt 5. Kapitel 2

Fråga AI

Fråga vad du vill eller prova någon av de föreslagna frågorna för att starta vårt samtal

Suggested prompts:

Can you explain more about how method overriding works in TypeScript?

What happens if I don't use the super keyword in the derived class?

Can you give another example of method overriding with different classes?

Awesome!

Completion rate improved to 5

Svep för att visa menyn


              123456789101112131415161718
            
class Animal {
  makeSound() {
    console.log("Some generic animal sound");
  }
}

class Dog extends Animal {
  makeSound() {
    super.makeSound();
    console.log("Woof!");
  }
}

const myDog = new Dog();
myDog.makeSound();
// Output:
// Some generic animal sound
// Woof!

Var allt tydligt?

Tack för dina kommentarer!

Avsnitt 5. Kapitel 2