Head Rush Ajax

236

Chapter 4

if (someNode.nodeType == Node.ELEMENT_NODE) {

// Do something with the element node

} else if (someNode.nodeType == Node.TEXT_NODE) {

// Do something with the text node

}

I like most of this DOM stuff so far, but all

this null value and undened stuff kind of

freaks me out. Can’t I just ask the node if it’s

an element, or text, or whatever?

Every node has a property called nodeType,

along with the nodeName and nodeValue

proeprties that you’ve already seen. The

nodeType property returns a number, and that

number maps to a value stored in the Node class.

There’s a value for each type of node, so you can

use these values to gure out exactly what kind

of node you’re working with, like this:

You can! (well, sort of)

Here’s the nodeType property.

It returns a number...

...that you can compare to the

numbers dened in the Node class.

There are numbers dened

for all the node types,

including elements, text,

and attributes.

Once you know what type

of node you have, you can

avoid using properties that

would return null values.

node types