Classes

class Student{
//initialising an object
    constructor(roll,name){
        this.roll=roll;
        this.name=name;
    }
    //method
    display(){
        console.log(this.roll," -> ",this.name);
    }
}
let s1=new Student(101,"Ravi");
s1.display();
let s2=new Student(102,"Raj");
s2.display();

• Console

Prototype

Common property of all the objects of a common class.

To add properties to class after creation of object of class.

let std1=new Student(101,"Ravi");
let std2=new Student(102,"Raj");
Student.prototype.clg="PVP";
console.log(std1);
console.log(std2);
console.log(std1.__proto__);
console.log(std1.toString());

• Console

We can create a base object with generic props that can be used in other objects, the use prototype concept to inherit those props to child objects.

We can use static method *Object.setPrototypeOf( childName, baseName );*

let stud={
    college:"PVP",
    city:"Vijayawa
    da",
    ph:1234567890,
    display:function(){
        console.log(this.college," -> ",this.city," -> ",this.ph);
    }
}
let st1={
    name:"Ravi",
    age:21
};
let st2={
    name:"Raj",
    age:22
};
Object.setPrototypeOf(st1,stud);
Object.setPrototypeOf(st2,stud);
console.log(st1);

• Console

Class Inheritance vs Prototype Inheritance

// class inheritance
class Parent{
    college="PVP";
    city="Vijayawada";
    ph=1234567890;
}
class Child extends Parent{
    name="Pavan";
    age=18;
}
let c=new Child();
console.log(c);
//prototype inheritance
function Parent1(){
    this.college="PVP";
    this.city="Vijayawada";
    this.ph=1234567890;
}
function Child1(){
    this.name="Pavan";
    this.age=18;
}
Child1.prototype=new Parent1();
let c1=new Child1();
console.log(c1);

• Console