NodeIterator

NodeIterator is an interface in the Document Object Model (DOM) that allows for traversal through a node tree. It provides a way to iterate over a set of nodes that match certain criteria, such as a specific tag name or attribute.

The NodeIterator interface offers several methods to control the traversal. The most fundamental of these is nextNode(), which returns the next node in the iteration sequence. If there are no more nodes to visit, nextNode() returns null. The previousNode() method allows for backward traversal, returning the previous node in the sequence or null if there are no preceding nodes.

Other methods associated with NodeIterator include detach(), which releases the iterator and any associated resources, and skip(), which advances the iterator past a specified number of nodes.

NodeIterator is typically created using the document.createNodeIterator() method. This method takes a root node, a whatToShow filter, and an entity reference expansion callback as arguments. The whatToShow argument is a bitmask that specifies which types of nodes should be included in the iteration. The entity reference expansion callback is a function that determines how entity references are handled.

NodeIterator is a powerful tool for DOM manipulation and querying, enabling efficient navigation and processing of XML and HTML documents. It is particularly useful for tasks such as finding all elements with a specific attribute or collecting all text nodes within a document fragment.