Javascript TUTORIAL
Javascript Objects - Object Template
In the last page we looked at how to define a single Circle Object. In practice we would like to define a template for the cicle object. We should be able to create the instances of the circle as many times as possible.
The example below defines a template of the circle object and creates three instances of it.
Example - A circle object with properties
<html> <head> <script type="text/javascript"> <!-- /* ******************************************************** Example Circle Object Template and instances ******************************************************** */ /* ******************************************************** Let us define the structure of the object circle. ******************************************************** */ function circle(x,y,r) { this.xcoordinate=x; this.ycoordinate=y; this.radius=r; } /* ******************************************************** Let us create 3 instances of object circle ******************************************************** */ circle1 =new circle(0,0,10); circle2 =new circle(5,5,20); circle3 =new circle(10,10,30); document.write("The radius of the 1st circle is " + circle1.radius + " <p>"); document.write("The radius of the 2nd circle is " + circle2.radius + " <p>" ); document.write("The radius of the 3rd circle is " + circle3.radius + " <p>" ); //--> </script> </head> <body> </html> |
Note the template to create an instance of an object
Circle=new Object(); |
You can try the example at the link below which will open in a new window
Example - Circle Object Template
In the next page we will create methods on the object circle. We will see how to create area and circumference of the circle by writing methods.