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The NodeList Object/Interface

The NodeList object/interface is an ordered collection of nodes. Ordered means that they have a numbered place in a sequence.

The childNodes property of the Node object returns a NodeList, as shown in Listing 16.4.

Listing 16.4 A Property of an Object Returning a NodeList Object

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1:  //var docroot holds the root element of the document
2:  var children = docRoot.childNodes;

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Table 16.5 gives an overview of the NodeList object properties.

Table 16.5 NodeList Attributes/Properties
Name	Value
length	The number of nodes in the NodeList

Listing 16.6 shows a JavaScript example using this property.

Listing 16.6 Getting the Length of a NodeList

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1:  //children holds the NodeList Object with the child nodes
2:  var nrofchildren = children.length;

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Table 16.6 gives an overview of the NodeList object methods.

Table 16.6 NodeList Methods
Name	Returns
item(n)	The nth item (node) of the collection

Listing 16.7 shows a JavaScript example using this method.

Listing 16.7 Using the nth Item of a NodeList

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1:  //children holds the NodeList Object with the child nodes
2:  var i;
3:  for (i=0, i < children.length, i++) //loop over all child nodes
4:       return children.item(i).nodeName; //return the names

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We use a variable, I, for iterating over all the items of a NodeList containing the list of children.

In line 4 we return the name for every child (the tag name if the child is an element, the attributename if an attribute, and so on.

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