Objects in JavaScript: Understanding OOP Concepts and Examples

Objects in Javascript

• An object in JavaScript is an entity with property and type.
• A property is a variable attached to the object.
• These properties define the characteristics of the object.
• For example, car can be an object with properties color, model, etc.
• You can access the object's property using dot operator.
• In this example, car is an object with model as property

Example

var car = new Object();
car.model = 'Ford';
console.log(car.model);

Methods to Create Object

• Create an empty object and then add properties to the object: Example:

var obj={};
obj.prop1="Hello";
obj.prop2="World";
console.log(obj.prop1 + ' ' + obj.prop2);

• By using Object Literal ie. Name value pair: Example:

var student = {Name:"Ben",  age:20};
console.log(student);

• By using keyword new Example:

var obj= new Object();
obj.prop1="Hello";
obj.prop2="World";
console.log(obj.prop1 + ' ' + obj.prop2);

Nested Objects

• We can also have an object nested inside another object, i.e., an object will have another object as its property, which in turn has separate properties of its own.
• Just like the normal objects, these inner objects can also be accessed using dot operator.

Example:

var student = { Name:"Ben",  age:20 , degree: {class:"B.Tech",section:"A"}};

We can access the inner object, class by

console.log(student.degree.class);