효율적인 DOM 순회 기법

<div id="container">
  <ul id="myList">
    <li>Item 1</li>
    <li class="active">Item 2</li>
    <li>Item 3</li>
  </ul>
  <p>Some other text</p>
  <ul id="anotherList">
    <li>Item A</li>
    <li>Item B</li>
  </ul>
</div>

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.7.1/jquery.min.js"></script>
<script>
  $(document).ready(function() {
    // Find all <li> elements within #myList
    $('#myList').find('li').css('background-color', 'lightgreen');

    // You can also chain with specific selectors
    $('#myList').find('.active').css('font-weight', 'bold');
  });
</script>

<div class="grandparent">
  <div class="parent">
    <p>Some text here</p>
    <button id="myButton">Click Me</button>
  </div>
</div>

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.7.1/jquery.min.js"></script>
<script>
  $(document).ready(function() {
    $('#myButton').on('click', function() {
      // Find the closest ancestor div and add a border
      $(this).closest('div').css('border', '2px solid blue');
    });
  });
</script>

<ul id="menu">
  <li>Home</li>
  <li class="current">About</li>
  <li>Services</li>
  <li>Contact</li>
</ul>

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.7.1/jquery.min.js"></script>
<script>
  $(document).ready(function() {
    $('#menu li').on('click', function() {
      // Remove highlight from previously selected siblings
      $('#menu li').css('background-color', '');
      // Highlight the clicked item's siblings
      $(this).siblings().css('background-color', 'lightyellow');
      // Highlight the clicked item itself (optional)
      $(this).css('background-color', 'lightblue');
    });
  });
</script>

<div class="body-wrapper">
  <div class="container">
    <div class="row">
      <section>
        <article>
          <p>Hello <span>World!</span></p>
        </article>
      </section>
    </div>
  </div>
</div>

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.7.1/jquery.min.js"></script>
<script>
  $(document).ready(function() {
    // Find all parents of 'span' until the '.container' div
    $('span').parentsUntil('.container').css('border', '1px dashed orange');
  });
</script>