The Navigator Object

Using the navigator object we can retrieve information about the capabilities and nature of the browser that is executing our code. If we'd like to execute different code for different browsers, this is the object for us.

Properties

Instead of describing what each of the properties do, it's easier to use some and demonstrate them by querying some of the recent release of Microsoft and Netscape browsers using this JavaScript code:

alert(navigator.appName);
alert(navigator.appVersion);
alert(navigator.appCodeName);
alert(navigator.userAgent);
alert(navigator.cookieEnabled);

The following table shows the values that IE4 returned:

Property Value
appName Microsoft Internet Explorer
appVersion 4.0 (compatible; MSIE 4.0; Windows NT)
appCodeName Mozilla
userAgent Mozilla/4.0 (compatible; MSIE 4.0; Windows NT)
cookieEnabled True

For comparison here's the Navigator 4.02 values:

Property Value
appName Netscape
appVersion 4.02 [en] (WinNT; I; Nav)
appCodeName Mozilla
userAgent Mozilla/4.02 [en] (WinNT; I; Nav)
cookieEnabled undefined

The values for Navigator 3.01:

Property Value
appName Netscape
appVersion 3.01 (WinNT; I)
appCodeName Mozilla
userAgent Mozilla/3.01 (WinNT; I)
cookieEnabled True

And also the values for Internet Explorer 3.01:

Property Value
appName Microsoft Internet Explorer
appVersion 2.0 (compatible; MSIE 3.01; Windows NT)
appCodeName Mozilla
userAgent Mozilla/2.0 (compatible; MSIE 3.01; Windows NT)
cookieEnabled True

The appName and userAgent properties (and their derivatives appVersion and appCodeName) reflect the browser that is executing the script code.

In case you haven't heard the explanation behind the Mozilla code name yet… it goes like this: Marc Andreesen who helped to develop the Mosaic browser while in college, once he left, founded Netscape, and started work on a browser that should 'beat its chest and smash Mosaic.' Mosaic + Godzilla = Mozilla. Get it?

Methods

There are two methods of the navigator object.

Methods Description
javaEnabled Returns true or false depending on whether a Java VM is installed or not
taintEnabled Returns false, included for compatibility with Netscape Navigator – the title seems to be Microsoft's little joke!

Collections

There are two collections of the navigator object as well.

Collections Description
plugins An alias for the collection of all the <EMBED>ded objects in the page
mimeTypes Collection of all the document and file types supported by the browser

© 1997 by Wrox Press. All rights reserved.