Mastering JavaScript

Chapter 8
DOM
window.onload= function() {
var greeting = document.getElementById("greeting");
alert(greeting.innerHTML); //shows "Hello World" alert
}
Hello World!
Earthlings
What we discussed so far was the basics of DOM traversal in JavaScript. When
the DOM gets complex and you want sophisticated operations on the DOM, these
traversal and access functions seem limiting. With this basic knowledge with us, it's
time to get introduced to a fantastic library for DOM traversal (among other things)
called jQuery.
jQuery is a lightweight library designed to make common browser operations easier.
Common operations such as DOM traversal and manipulation, event handling,
animation, and Ajax can be tedious if done using pure JavaScript. jQuery provides
you with easy-to-use and shorter helper mechanisms to help you develop these
common operations very easily and quickly. jQuery is a feature-rich library, but as
far as this chapter goes, we will focus primarily on DOM manipulation and events.
You can add jQuery to your HTML by adding the script directly from a content
delivery network (CDN) or manually downloading the file and adding it to the
script tag. The following example shows you how to download jQuery from Google's
CDN:
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