Lära What is an Inheritance

Inheritance is another main OOP principle, which means that some classes can adopt properties of other classes, and maybe extend them.

Like, for example, we have class Rectangle which represents the rectangle instance. Then, let’s define class Square. Square is a Rectangle, too, so we can create this class from the Rectangle class. Use keyword extends:


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class Rectangle {
  height;
  width;
  constructor(height, width) {
    this.height = height;
    this.width = width;
    console.log('Rectangle created');
  }
}

class Square extends Rectangle{
}

Now Square has the same attributes and methods as Rectangle class.

The Rectangle is a base class, and Square is a derived class. Or you can say that Rectangle is a parent class and Square is a daughter class.

Square differs with sides length: height is equal to the width, unlike for Rectangle.

Usually, JavaScript classes such as an array, console, window, etc. inherit some base classes, which can inherit other classes. It is very advisable to extend existing classes, not to define similar classes again.

Uppgift

Swipe to start coding

Create Fruit and Apple class, such that Apple is a daughter class for Fruit class. Let these classes be empty for now.

Lösning

Byt till skrivbordet för praktisk övningFortsätt där du är med ett av alternativen nedan

Var allt tydligt?

Tack för dina kommentarer!

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Inheritance is another main OOP principle, which means that some classes can adopt properties of other classes, and maybe extend them.


              123456789101112
            
class Rectangle {
  height;
  width;
  constructor(height, width) {
    this.height = height;
    this.width = width;
    console.log('Rectangle created');
  }
}

class Square extends Rectangle{
}

Now Square has the same attributes and methods as Rectangle class.

The Rectangle is a base class, and Square is a derived class. Or you can say that Rectangle is a parent class and Square is a daughter class.

Square differs with sides length: height is equal to the width, unlike for Rectangle.

Uppgift

Swipe to start coding

Create Fruit and Apple class, such that Apple is a daughter class for Fruit class. Let these classes be empty for now.

Lösning

Byt till skrivbordet för praktisk övningFortsätt där du är med ett av alternativen nedan

Var allt tydligt?

Tack för dina kommentarer!

Avsnitt 4. Kapitel 1

single

Svep för att visa menyn

Inheritance is another main OOP principle, which means that some classes can adopt properties of other classes, and maybe extend them.


              123456789101112
            
class Rectangle {
  height;
  width;
  constructor(height, width) {
    this.height = height;
    this.width = width;
    console.log('Rectangle created');
  }
}

class Square extends Rectangle{
}

Now Square has the same attributes and methods as Rectangle class.

The Rectangle is a base class, and Square is a derived class. Or you can say that Rectangle is a parent class and Square is a daughter class.

Square differs with sides length: height is equal to the width, unlike for Rectangle.

Uppgift

Swipe to start coding

Create Fruit and Apple class, such that Apple is a daughter class for Fruit class. Let these classes be empty for now.

Lösning

Byt till skrivbordet för praktisk övningFortsätt där du är med ett av alternativen nedan

Var allt tydligt?

Tack för dina kommentarer!

What is an Inheritance

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Awesome!

What is an Inheritance

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Awesome!

What is an Inheritance

Lösning