Working with Checkboxes, Radio Buttons, and Dropdowns

What problem does this code solve for dynamic select elements?

const observer = new MutationObserver(mutations => {
  mutations.forEach(mutation => {
    if (mutation.type === 'childList') {
      updateSelectUI(mutation.target);
    }
  });
});

observer.observe(select, { childList: true });

Performance optimization
Event handling
Dynamic UI updates
This code uses MutationObserver to handle dynamic changes to select elements. Benefits: 1) Automatically detects when options are added or removed, 2) Allows UI updates in response to dynamic content changes, 3) Works with both script-driven and framework-driven changes, 4) More efficient than polling for changes, 5) Handles asynchronous option updates reliably. This pattern is essential for select elements that have their options updated dynamically through various means.
Form validation

Next Question (21/22)