This section provides a quick description of the 'this' keyword, which represents the current object in object method. A tutorial example is provided on how to access properties and methods of the current object.
While defining a function to be used as a method for objects,
you can use the keyword "this" to represent the current object the method is called against.
The "this" keyword in JavaScript has the same usage as in Java.
Here is tutorial example of using "this" keyword to access properties and methods of the current project:
<html>
<!-- Object_this_Keyword.html
Copyright (c) 2008 by Dr. Herong Yang, http://www.herongyang.com/
-->
<head>
<title>"this" Keyword in Object Methods</title>
</head>
<body>
<pre>
<script type="text/javascript">
// Using "this" to get the properties
function myToString() {
return '"'+this.title + '" by '+this.author;
}
// Using "this" to get the "toString" method
function showAll() {
window.alert(this.toString());
}
// Preparing one of "Object" type
var myBook = new Object();
myBook.author = "Herong Yang";
myBook.title = "JavaScript Tutorials";
// Adding a new method to one object only
myBook.print = showAll;
// Overriding "toString()" on one object only
myBook.toString = myToString;
// Calling the method on "myBook"
myBook.print();
</script>
</pre>
</body>
</html>
If you run this "this" keyword example, you will get an alert box with the message of: "JavaScript Tutorials" by Herong Yang.
