JavaScript prototype Property: Number Object


The prototype property is used to add new properties and methods to a number object.


Implemented in JavaScript 1.1


myobj.prototype.name = value 

myobj: The name of the constructor function object you want to change.

name: The name of the property or method to be created.

value: The value initially assigned to the new property or method. If you add a property to the prototype for an object, then all objects created with that object's constructor function will have that new property, even if the objects existed before you created the new property.


The following web document demonstrates how the prototype property can be used.

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<meta http-equiv="content-type" content="text/html; charset=iso-8859-1" />
<title>JavaScript Number object - prototype property example</title>
<h1 style="color: red">JavaScript Number object : prototype property</h1>
<hr />
<script type="text/javascript">
//This is done to make the following JavaScript code compatible to XHTML. <![CDATA[
var mynum = new Number();
function square(x){
var numsqr;
numsqr = (x * x);
return numsqr;
Number.prototype.sqrcal = square;
document.write("sqaure of 202 is: " +mynum.sqrcal(202) + "<br>");

View the example in the browser

Supported Browser

Internet Explorer 7 Firefox 3.6 Google Chrome 7 Safari 5.0.1 Opera 10
Yes Yes Yes Yes Yes

See also:

JavaScript Core objects, methods, properties.

Previous: JavaScript POSITIVE_INFINITY Property: Number Object
Next: JavaScript toSource Method: Number Object

Test your Programming skills with w3resource's quiz.

Follow us on Facebook and Twitter for latest update.