December 30, 1999 - The DOM's Properties

Yehuda Shiran December 30, 1999
The DOM's Properties
Tips: December 1999

Yehuda Shiran, Ph.D.
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The Document Object Model provides a set of properties that you can use to navigate, access, and update the document tree with. The following table shows the read-only properties:

DOM's PropertyReturnsComments
firstChildThe first child node.An [object]. All children are included in childNodes collection.
lastChildThe last child node.An [object]. All children are included in childNodes collection.
nextSiblingThe next child of the node's parent.An [object].
nodeNameThe HTML Tag.Examples: P, FONT, UL.
nodeTypeWhether the node is a tag, text, or attribute.Returns 1 for tag, 2 for attribute, and 3 for text.
parentNodeA reference to the parent node.An [object].
previousSiblingA reference to the previous child of the node's parent.An [object].
specifiedWhether an attribute value is set.Boolean

The following table shows the read-write properties:

DOM's PropertyReturnsComments
dataThe value of a text node.A string. Returns undefined for all other nodes. Can be set as well.
nodeValueThe value of a text node.A string. Returns null for all other nodes. Can be set as well.

And finally, here are the collections defined for the DOM:

DOM's PropertyReturnsComments
attributesA collection of the node's attributes.Access by name. Example:attributes.id.
childNodesA collection of the node's children.Access by index. Example:childNodes[2].

Learn all about the DOM in Column 40, The DOM, Part I: Analysis.