JavaScript Tutorials - Herong's Tutorial Examples - 2.33, by Herong Yang
Objects with Indexed Properties
This section provides a quick description of indexed properties and indexed methods. A tutorial example is provided on how to create and access indexed properties and indexed methods.
JavaScript also supports objects with indexed properties with the following features:
Here is a tutorial example on how to define and access object's indexed properties and indexed methods in two formats: array format and associate array format:
<html> <!-- Object_Indexed_Properties.html Copyright (c) 2008 HerongYang.com. All Rights Reserved. --> <head> <title>Objects with Indexed Properties</title> </head> <body> <pre> <script type="text/javascript"> // Using "this" to get the properties function myToString() { return '"'+this.title + '" by '+this.author; } // Using object literal format var myBook = { author: "Herong Yang", title: "JavaScript Tutorials", 3: 2008, price: "Free", 4: myToString }; // Adding a new indexed property myBook[9] = "Programming"; // An index property can not be accessed with (.) // document.writeln("myBook.3: "+myBook.3); // Getting indexed property values document.writeln("myBook[3]: "+myBook[3]); document.writeln("myBook['3']: "+myBook['3']); document.writeln("myBook[4]: "+myBook[4]); document.writeln("myBook[9]: "+myBook[9]); // Checking property data types document.writeln(); document.writeln(myBook[4]()); </script> </pre> </body> </html>
The output of this tutorial example matches my expectation:
myBook[3]: 2008 myBook['3']: 2008 myBook[4]: function myToString() { return "\"" + this.title + "\" by " + this.author; } myBook[9]: Programming "JavaScript Tutorials" by Herong Yang
Table of Contents
ECMAScript Language Specification and JavaScript Dialects
Data Types, Variables and Expressions
Creating, Accessing, and Manipulating Arrays
Defining and Calling Functions
Web Browser Supporting JavaScript
Server-Side and Client-Side Web Scripting
Adding and Deleting Object Own Properties
Adding and Deleting Object Own Methods
Using "this" Keyword to Represent Current Object
Object Literals of the "Object" Type
►Objects with Indexed Properties
Differences between "Object" and "Array"
Using "Array" Objects as "Object" Objects
Defining Your Own Object Types
Inheritance of Properties and Methods through the Prototype Object Chain
'jrunscript' - JavaScript Shell Command from JDK
Using Functions as "Function" Objects
Introduction to Built-in Object Types
W3C's Document Object Model (DOM) Specifications