how to define classes in javascript code example

Example 1: javascript create class

class Person {
 constructor(name, age) {
   this.name = name;
   this.age = age;
 }
  present = () => { //or present(){
  	console.log(`Hi! i'm ${this.name} and i'm ${this.age} years old`) 
  }
}
let me = new Person("tsuy", 15);
me.present();
// -> Hi! i'm tsuy and i'm 15 years old.

Example 2: javascript class

class Rectangle {
  constructor(height, width) {
    this.height = height;
    this.width = width;
  }
  // Getter
  get area() {
    return this.calcArea();
  }
  // Method
  calcArea() {
    return this.height * this.width;
  }
}

const square = new Rectangle(10, 10);

console.log(square.area); // 100