JavaScript Tutorials - Herong's Tutorial Examples - 2.33, by Herong Yang
Object Literals of the "Object" Type
This section provides a quick description of object literals or initializers for creating new objects of the 'Object' type. A tutorial example is provided on how to initialize an object with two properties and two methods.
In previous sections we learned that objects of "Object" type can be created with the constructor function "new Object()".
JavaScript also support a simpler way to create objects of "Object" type using object literals in the format of:
{property1: value1, property2: value2, ...}
where "property1" and "property2" are property or method names. In JavaScript language, properties and methods in an object are really managed in an identical way.
An object literal is also called object initializer, because it allows you to create a new object and to initialize it with properties and methods in a single operation.
Using an object literal to create an object has the same result as using the constructor. But object literals are much easier to use. The following two code segments are identical. But the first one is much simpler:
// Creating an object with an object literal var obj = {property1: value1, property2: value2, ...}; // Creating an object with the constructor var obj = new Object(); obj.property1 = value1; obj.property2 = value2; ...;
Here is a tutorial example of creating an object of the "Object" type with an object literal, or initializer:
<html> <!-- Object_Literal.html Copyright (c) 2008 HerongYang.com. All Rights Reserved. --> <head> <title>Object Literals of "Object" Type</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()); } // Using object literal format var myBook = { author: "Herong Yang", title: "JavaScript Tutorials", print: showAll, toString: myToString }; // Calling the method on "myBook" myBook.print(); </script> </pre> </body> </html>
If you run this tutorial example, you will get the same result as the example in the previous section: "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