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Interface TreeWalker

The TreeWalker object represents the nodes of a document subtree and a position within them.

MDN Reference

interface TreeWalker {
    currentNode: Node;
    filter: NodeFilter | null;
    root: Node;
    whatToShow: number;
    firstChild(): Node | null;
    lastChild(): Node | null;
    nextNode(): Node | null;
    nextSibling(): Node | null;
    parentNode(): Node | null;
    previousNode(): Node | null;
    previousSibling(): Node | null;
}
Index
currentNode filter root whatToShow
firstChild lastChild nextNode nextSibling parentNode previousNode previousSibling
currentNode: Node

The TreeWalker.currentNode property represents the Node which the TreeWalker is currently pointing at.

MDN Reference

filter: NodeFilter | null

The TreeWalker.filter read-only property returns the NodeFilter associated with the TreeWalker.

MDN Reference

root: Node

The TreeWalker.root read-only property returns the root Node that the TreeWalker traverses.

MDN Reference

whatToShow: number

The TreeWalker.whatToShow read-only property returns a bitmask that indicates the types of nodes to show. Non-matching nodes are skipped, but their children may be included, if relevant.

MDN Reference

  • The TreeWalker.firstChild() method moves the current Node to the first visible child of the current node, and returns the found child. If no such child exists, it returns null and the current node is not changed.

    MDN Reference

    Returns Node | null

  • The TreeWalker.lastChild() method moves the current Node to the last visible child of the current node, and returns the found child. If no such child exists, it returns null and the current node is not changed.

    MDN Reference

    Returns Node | null

  • The TreeWalker.nextNode() method moves the current Node to the next visible node in the document order, and returns the found node. If no such node exists, it returns null and the current node is not changed.

    MDN Reference

    Returns Node | null

  • The TreeWalker.nextSibling() method moves the current Node to its next sibling, if any, and returns the found sibling. If there is no such node, it returns null and the current node is not changed.

    MDN Reference

    Returns Node | null

  • The TreeWalker.parentNode() method moves the current Node to the first visible ancestor node in the document order, and returns the found node. If no such node exists, or if it is above the TreeWalker's root node, it returns null and the current node is not changed.

    MDN Reference

    Returns Node | null

  • The TreeWalker.previousNode() method moves the current Node to the previous visible node in the document order, and returns the found node. If no such node exists, or if it is before that the root node defined at the object construction, it returns null and the current node is not changed.

    MDN Reference

    Returns Node | null

  • The TreeWalker.previousSibling() method moves the current Node to its previous sibling, if any, and returns the found sibling. If there is no such node, it returns null and the current node is not changed.

    MDN Reference

    Returns Node | null

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