JavaScript를 사용하여 웹페이지에서 탐색 변경 사항을 어떻게 감지하고 처리할 수 있습니까?

<code class="javascript">var oldHref = document.location.href;

window.onload = function() {
    var bodyList = document.querySelector('body');

    var observer = new MutationObserver(function(mutations) {
        if (oldHref != document.location.href) {
            oldHref = document.location.href;
            /* Changed ! your code here */
        }
    });
    
    var config = {
        childList: true,
        subtree: true
    };
    
    observer.observe(bodyList, config);
};</code>

<code class="javascript">const observeUrlChange = () => {
  let oldHref = document.location.href;
  const body = document.querySelector('body');
  const observer = new MutationObserver(mutations => {
    if (oldHref !== document.location.href) {
      oldHref = document.location.href;
      /* Changed ! your code here */
    }
  });
  observer.observe(body, { childList: true, subtree: true });
};

window.onload = observeUrlChange;</code>