The read-only invalidIteratorState property of the XPathResult interface signifies that the iterator has become invalid. It is true if XPathResult.resultType is UNORDERED_NODE_ITERATOR_TYPE or ORDERED_NODE_ITERATOR_TYPE and the document has been modified since this result was returned.
A boolean value indicating whether the iterator has become invalid.
The following example shows the use of the invalidIteratorState property.
<div>XPath example</div>
<p>Iterator state: <output></output></p>
const xpath = "//div";
const result = document.evaluate(
xpath,
document,
null,
XPathResult.ANY_TYPE,
null,
);
document.querySelector("div").remove();
document.querySelector("output").textContent = result.invalidIteratorState
? "invalid"
: "valid";