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.
previousNode()None.
A Node object or null.
const treeWalker = document.createTreeWalker(
document.body,
NodeFilter.SHOW_ELEMENT,
{
acceptNode(node) {
return NodeFilter.FILTER_ACCEPT;
},
},
false,
);
const node = treeWalker.previousNode(); // returns null as there is no parentTreeWalker interface it belongs to.