polymorphism.js

class User {
  constructor(name) {
    this.name = name;
  }
  
  sayHi() {
    console.log(`Hi, ${this.name}`);
  }
}

class Admin extends User {
  constructor(name) {
    super(name);
    this.isAdmin = true;
  } 
  sayHi() {
    console.log(`Hi, my name is Admin ${this.name}`);   
  }
}
let admin = new Admin('Mohanad');
admin.sayHi(); // Hi, my name is Admin Mohanad