NodeIterator.detach() is a no-op kept only for backward compatibility. Per MDN, it once invalidated the iterator; today it does nothing useful.
Pass the required arguments shown below. Check return values and browser support before you rely on the result.
Call iterator.detach. Start with this line.
nodeIterator.detach()| Call | What it does |
|---|---|
nodeIterator.detach() | Primary signature. |
iterator.detach(...) | Call with the arguments your case needs. |
Built into the browser. Call detach(...) on a NodeIterator — no import required.
nodeIterator.detach()This member has no parameters beyond those shown in the signature.
| Return Value | Description |
|---|---|
| * | undefined |
undefineddetach() completes but gives no useful value.
const it = document.createNodeIterator(
document.querySelector("#box"),
NodeFilter.SHOW_ELEMENT
);
const result = it.detach();
console.log(result); // undefined#box, show elements only.detach(). No arguments.undefined.nextNode() After detach()In modern browsers the iterator keeps working (no-op).
const it = document.createNodeIterator(
document.querySelector("#box"),
NodeFilter.SHOW_ELEMENT
);
it.detach();
const node = it.nextNode();
console.log(node ? node.nodeName : "null");nextNode(). Modern engines still return a node.DIV).detach() instead of testing it.MDN’s old example expected INVALID_STATE_ERR; modern browsers usually do not throw.
const nodeIterator = document.createNodeIterator(
document.querySelector("#box"),
NodeFilter.SHOW_ELEMENT,
{ acceptNode() { return NodeFilter.FILTER_ACCEPT; } }
);
nodeIterator.detach();
let threw = false;
try {
nodeIterator.nextNode();
} catch (e) {
threw = true;
}
console.log("threw INVALID_STATE_ERR? " + threw);detach(). No-op today.nextNode(). Catch any exception.false. Modern browsers do not invalidate the iterator.typeof detachThe method still exists as a function for compatibility.
const it = document.createNodeIterator(
document.querySelector("#box"),
NodeFilter.SHOW_ELEMENT
);
console.log(typeof it.detach); // "function"typeof it.detach.detach()Modern pattern: finish the loop and let the iterator go out of scope.
function collectTagNames(root) {
const it = document.createNodeIterator(root, NodeFilter.SHOW_ELEMENT);
const names = [];
let node;
while ((node = it.nextNode())) names.push(node.nodeName);
return names; // no detach() — just return
}
console.log(JSON.stringify(
collectTagNames(document.querySelector("#box"))
));it lives inside the function.nextNode. Collect element tag names.NodeIterator.detach() is marked Deprecated on MDN. The method still exists in browsers as a no-op for compatibility. It is a browser DOM API — not a Node.js built-in.
Present across modern browsers for compatibility, but do not use it in new projects.
Bottom line: Do not call detach() in new code. Walk with nextNode/previousNode, then drop the iterator reference.
Walk forward through the nodes your iterator accepts.
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