034-Class-Inheritance.js

/*
 * Author : Jaydatt Patel

Inheritance :

- You can derive new class from base or super class using 'extends' keyword. 
- You can inhetits all Properties of super class but private properties can not be inherit. 
- You can access method or variable of super class in derived class using 'super' keyword. 
- You can also add prototype for class same as constructor function.

syntax: 
        class derived_class extends base_class{
            ....
        }

 */

class Person {
  #type = "person";
  constructor(name, age, gender) {
    this.name = name;
    this.age = age;
    this.gender = gender;
  }

  show() {
    return `${this.name}, ${this.age}, ${this.gender}`;
  }
}

class Student extends Person {
  constructor(roll, course, name, age, gender) {
    super(name, age, gender); //calling base class constructor
    this.roll = roll;
    this.course = course;
    // this.#type = 'student'; // Error: Private variable of base class
  }

  show() {
    // calling base class method which is overridden
    return super.show() + `, ${this.roll}, ${this.course}`;
  }
}

console.log("-------------------------------");
var st1 = new Student(101, "Computer", "Amit", 22, "Male");
console.log(st1.show());
console.log(st1);