console-1628868212250.log

class Person{
constructor(name, age){
    this.name = name;
    this.age = age;
}
print(){
console.log(`Name ${this.name} Age ${this.age}`);
}
}
class Student extends Person{
constructor(rollno, marks, name, age){
    super(name, age); // Parent Cons Call
    this.rollno = rollno;
    this.marks = marks;
}
print(){
super.print();// call parent
console.log(`Rollno ${this.rollno} Marks ${this.marks}`);
}
}
class Employee extends Student{
constructor(id, salary, rollno, marks, name, age){
super(rollno, marks, name,age); // call parent constructor
this.id = id;
this.salary = salary;
}
printEmp(){
super.print(); // call parent print
console.log(`Id ${this.id} Salary ${this.salary}`);
}
}
var ram = new Employee(1001, 9000,2,90,"Ram",21);
ram.printEmp();

VM1129:7 Name Ram Age 21
VM1129:18 Rollno 2 Marks 90
VM1129:29 Id 1001 Salary 9000
undefined
typeof Employee;
"function"
typeof Student;
"function"
Employee.prototype;
Student {constructor: ƒ, printEmp: ƒ}
Employee.prototype.__proto__;
Person {constructor: ƒ, print: ƒ}
Employee.prototype.__proto__ == Student.prototype;
true
ram;
Employee {name: "Ram", age: 21, rollno: 2, marks: 90, id: 1001, …}
ram.__proto__ === Employee.prototype;
true
Employee.prototype.__proto__ == Student.prototype
true
Student.prototype.__proto__ === Person.prototype;
true