There are several ways to serialize JavaScript objects to XML, but one of the most commonly used methods is to use the XMLSerializer object in the browser.

Here’s an example code snippet that demonstrates how to use XMLSerializer to serialize a JavaScript object to XML:

const obj = {
  name: "John Doe",
  age: 30,
  city: "New York"
};

const serializer = new XMLSerializer();
const xmlString = serializer.serializeToString(objToXml(obj));

console.log(xmlString);

function objToXml(obj) {
  const xml = document.createElement("object");

  for (const [key, value] of Object.entries(obj)) {
    const element = document.createElement(key);
    element.textContent = value;
    xml.appendChild(element);
  }

  return xml;
}

In this example, we define a JavaScript object obj with some properties. We then define a function objToXml that converts the object to an XML document using document.createElement() and document.createTextNode() to create XML elements and text nodes. Finally, we use XMLSerializer to convert the resulting XML document to a string.

Note that this example assumes that all of the values in the JavaScript object are strings. If the values can be other types, such as numbers or booleans, you will need to convert them to strings before serializing them to XML.