html
<body> <nav class="navbar navbar-light bg-light"> <div class="container-fluid"> <span class="navbar-brand">Navbar</span> <button class="navbar-toggler" type="button"> <span class="navbar-toggler-icon"></span> </button> </div> </nav> <ul class="list-group"> <li class="list-group-item">An item</li> <li class="list-group-item">A second item</li> <li class="list-group-item">A third item</li> <li class="list-group-item">A fourth item</li> <li class="list-group-item">And a fifth one</li> </ul> <script> document.getElementsByClassName('navbar-toggler')[0].addEventListener('click',function(){ document.getElementsByClassName('list-group')[0].classList.add('show'); }) </script> </body>css
.list-group{ display: none; } .show{ display: block; }
확장
<script> document.getElementsByClassName('navbar-toggler')[0].addEventListener('click',function(){ document.getElementsByClassName('list-group')[0].classList.toggle('show'); }) </script>
위와 같이 사용하면 클래스명이 있으면 제거 없으면 붙여준다.
querySelector()
<ul class="list-group"> <li class="list-group-item">An item</li> <li class="list-group-item">A second item</li> <li class="list-group-item">A third item</li> <li class="list-group-item">A fourth item</li> <li class="list-group-item">And a fifth one</li> </ul>
여기서
.document.querySelector('.list-group')
.document.querySelector('.list-group-item')
->
<li class="list-group-item">An item</li>
.document.querySelectorALL('list-group-item)
-> 모든 요소
.document.querySelector('.list-group-item').[2]
->
<li class="list-group-item">A third item</li>