Classes

Constructor

A constructor's purpose is to allocate you an object and then return immediately.

Class-related Keywords

super

The super keyword is used to access and call functions on an object's parent.

• ex. If we have Dog extend from Mammal, then calling super.get in Dog will call the get method of the Mammal class.

spec: When used in a constructor, calling super calls the constructor method of the parent.

• the super keyword appears alone and must be used before the this keyword is used.

Note that a rectangle is more generic than a square. Therefore, we can create a Square class that extends a Rectangle class, and simplify the interface of the Square.

class Rectangle {
    constructor(height, width) {
        this.height = height;
        this.width = width;
    }
}
class Square extends Rectangle {
    constructor(length) {
        super(length)
    }
}

We can call super on methods that have the static modifier.