class keyword es6

1class Rectangle {
2  constructor(height, width) {
3    this.height = height;
4    this.width = width;
5  }
6  // Getter
7  get area() {
8    return this.calcArea();
9  }
10  // Method
11  calcArea() {
12    return this.height * this.width;
13  }
14}
15
16const square = new Rectangle(10, 10);
17
18console.log(square.area); // 100

1class MyClass {
2  constructor() {
3    this.answer = 42;
4  }
5}
6
7const obj = new MyClass();
8obj.answer; // 42

1class Polygon {
2  constructor(...sides) {
3    this.sides = sides;
4  }
5  // Method
6  *getSides() {
7    for(const side of this.sides){
8      yield side;
9    }
10  }
11}
12
13const pentagon = new Polygon(1,2,3,4,5);
14
15console.log([...pentagon.getSides()]); // [1,2,3,4,5]