The NodeIterator interface represents an iterator to traverse nodes of a DOM subtree in document order.

A NodeIterator can be created using the Document.createNodeIterator() method, as follows:

const nodeIterator = document.createNodeIterator(root, whatToShow, filter);

This interface doesn't inherit any property.

NodeIterator.root Read only

Returns a Node representing the root node, as specified when the NodeIterator was created.

NodeIterator.whatToShow Read only

Returns an unsigned long bitmask that describes the types of Node to be matched. Non-matching nodes are skipped, but relevant child nodes may be included.

The possible bitmask values are constants from the NodeFilter interface:

Constant	Numerical value	Description
NodeFilter.SHOW_ALL	4294967295 (that is the max value of unsigned long)	Shows all nodes.
NodeFilter.SHOW_ATTRIBUTE Deprecated	2	Shows attribute Attr nodes. This is meaningful only when creating a NodeIterator with an Attr node as its root; in this case, it means that the attribute node will appear in the first position of the iteration or traversal. Since attributes are never children of other nodes, they do not appear when traversing over the document tree.
NodeFilter.SHOW_CDATA_SECTION Deprecated	8	Shows CDATASection nodes.
NodeFilter.SHOW_COMMENT	128	Shows Comment nodes.
NodeFilter.SHOW_DOCUMENT	256	Shows Document nodes.
NodeFilter.SHOW_DOCUMENT_FRAGMENT	1024	Shows DocumentFragment nodes.
NodeFilter.SHOW_DOCUMENT_TYPE	512	Shows DocumentType nodes.
NodeFilter.SHOW_ELEMENT	1	Shows Element nodes.
NodeFilter.SHOW_ENTITY Deprecated	32	Legacy, no longer used.
NodeFilter.SHOW_ENTITY_REFERENCE Deprecated	16	Legacy, no longer used.
NodeFilter.SHOW_NOTATION Deprecated	2048	Legacy, no longer used.
NodeFilter.SHOW_PROCESSING_INSTRUCTION	64	Shows ProcessingInstruction nodes.
NodeFilter.SHOW_TEXT	4	Shows Text nodes.

NodeIterator.filter Read only

Returns a NodeFilter used to select the relevant nodes.

NodeIterator.referenceNode Read only Experimental

Returns the Node to which the iterator is anchored.

NodeIterator.pointerBeforeReferenceNode Read only

Returns a boolean indicating whether or not the NodeIterator is anchored before the NodeIterator.referenceNode. If false, it indicates that the iterator is anchored after the reference node.

This interface doesn't inherit any method.

NodeIterator.detach() Deprecated

This is a legacy method, and no longer has any effect. Previously it served to mark a NodeIterator as disposed, so it could be reclaimed by garbage collection.

NodeIterator.previousNode()

Returns the previous Node in the document, or null if there are none.

NodeIterator.nextNode()

Returns the next Node in the document, or null if there are none.

• The creator method: Document.createNodeIterator().
• Related interface: TreeWalker