Name
NodeList — a read-only array of nodes
Availability
DOM Level 1 Core
Properties
-
readonly unsigned long length The number of nodes in the array.
Methods
-
item( ) Returns the specified element of the array.
Description
The NodeList interface defines a read-only ordered list (i.e., an
array) of Node objects. The length property
specifies how many nodes are in the list, and the item( ) method allows you to obtain the node at a specified
position in the list. The elements of a NodeList are always valid
Node objects: NodeLists never contain null
elements.
In JavaScript, NodeList objects behave like JavaScript arrays, and
you can query an element from the list using square-bracket array
notation instead of calling the item( ) method.
However, you cannot assign new nodes to a NodeList using square
brackets. Since it is always easier to think of a NodeList object as
a read-only JavaScript array, this book uses the notation
Node[] (i.e., a Node array) instead of NodeList.
See Element.getElementsByTagName( ), for example, which
is listed as returning a Node[] instead of a
NodeList object. Similarly, the childNodes
property of the Node object is technically a NodeList object, but the
“Node” reference page defines it as a
Node[], and the property itself is usually
referred to as “the childNodes[]
array.”
Note that NodeList objects are “live”: they are not static, but immediately reflect changes to the document tree. For example, if you have a NodeList that represents the children of a specific ...