How to associate functions with objects using JavaScript?

In JavaScript you can associate functions with objects. Here we will demonstrate how the constructor creates the object and assigns properties.

Object is a standalone entity, with properties and type in JavaScript. JavaScript objects can have properties, that define their characteristics.

Objects and properties:

An object in JavaScript has properties associated with this. So, a property of an object can be explained as a variable which is attached to an object. Thus, object properties are mostly the same as simple JavaScript variables, except for the attachment to objects.

JavaScript has a number of predefined objects. So, in addition, you can create your own objects.

Inheritance:

Objects in JavaScript are inherited from at least one other object.
So, the object which is being inherited from is known as a prototype, and the inherited properties can be found in the prototype object of a constructor.

Example,

var myCar = new Object();
myCar.make = "Nissan";
myCar.model = "N-54";
myCar.year = 1972;

Let’s now create a custom “toString()” method for our user object. We can embed the function directly in the object like this:

<script type="text/javascript">
function user(name, email) {
this.name = name;
this.email = email;
this.toString = function userToString() {
return("Name: "+this.name+" Email: "+this.email);
}
}
var obj = new user("John Doe","john.doe@example.com");
document.write(obj.toString());
</script>

This produces:
Name: John Doe Email: john.doe@example.com