JavaScript - 构造函数

<script>
class Employee {
  constructor() {
    this.id=101;
    this.name = "Martin Roy";
  } 
}
var emp = new Employee();
document.writeln(emp.id+" "+emp.name);
</script>

<script>
class CompanyName
{
  constructor()
  {
    this.company="Learnfk";
  }
}
class Employee extends CompanyName {
  constructor(id,name) {
   super();
    this.id=id;
    this.name=name;
  } 
}	
var emp = new Employee(1,"John");
document.writeln(emp.id+" "+emp.name+" "+emp.company);
</script>