class People {
  constructor(newname, newage) {
    this.name = newname;
    this.age = newage;
  }
  showname() {
    alert(this.name);
  }
  changename(newname) {
    this.name = newname;
  }
}
class Badge extends People {
  showbadge() {
    alert(this.name + ": " + this.age);
  }
}
const badge = new Badge("Robert", 52);
badge.showbadge();