Difference Between Objects and Prototypes in JavaScript

Last Updated : 11 Dec, 2023

Objects in JavaScript

The Objects in JavaScript are instances of the class or constructors and they can hold properties and methods. These properties and methods can be unique to the object or inherited from the prototypes. The Objects can be created using the constructor functions, object literals, or Object constructors.

Syntax:

const person = {
      name: 'Kumar',
      age: 20,
      greet: function() {
     // code
  }
};

Example: In this Example, a car object might have properties like "make" and "model" and methods for starting the engine or changing gears.

JavaScript

car1 = { make: 'Toyota', model: 'Camry' };

// Adding a method to object
car1.start = function () {
    console.log('Engine started');
};

// Using the object and its method
car1.start();

Output

Engine started

Prototypes in JavaScript

The Prototypes in JavaScript are template objects that provide shared properties and methods to the other objects. Every object has a built-in property that is called its prototype. and prototype is an object itself so it also has its own prototype. They are not created explicitly as prototypes but exist as a blueprint for the objects of the specific type. The Prototypes facilitate inheritance by allowing the objects to inherit their properties and methods.

Syntax:

function Person(name, age) {
  this.name = name;
  this.age = age;
}
Person.prototype.greet = function() {
// code
}

Example: In this example, a Cars constructor function is defined to create car objects with make and model properties, and a shared start method is added to the Cars prototype for initiating the engine.

JavaScript

function Cars(make, model) {
    this.make = make;
    this.model = model;
}
// Adding a shared method to Car prototype
Cars.prototype.start = function () {
    console.log('Engine started');
};
// Creating car objects
const myCars = new Cars('Toyota', 'Camry');
const anotherCars = new Cars('TATA', 'Accord');
// Using the shared method from prototype
myCars.start();
anotherCars.start();

Output

Engine started
Engine started