Lesson 5: Object's Properties and Methods
Object
An object
is a collection of data that includes the properties, other objects,
and associated function (methods) of the object. Your web page is an
example of an object. Any table, image, button or form is also an object.
In the Java statement from lesson 1 below, document is the object.
document.writeln
('This text is written with Java code<br>');
PROPERTIES
Each object has certain properties. When you change the details about
something which already exists you are changing its properties. For
example the background color of your document is written: document.bgcolor.
To change your background to the color red you would write the line:
document.bgcolor="red".
METHODS
Whenever
you need to DO something, like write text to the screen in lesson
1, you are using a method. Most objects have a certain collection
of things they can do. Just as a a door can open or close, different
objects can do different things. A new document is opened with the method
document.open(). You can write "Java is
Fun" into a document by typing document.write("JavaScript
is Fun") In these examples open() and write() are both methods
of the object: document.
Some
other important JavaScript objects include: String Object, Array Object,
Date Object, Math Object, Window Object, Frame Object, Form Object
Browser Object. For more information on these goto: http://www.w3schools.com/js/default.asp
