# 3 列表切換  ~~~ <ul> <li class="one">1</li> <li class="one">2</li> <li class="one">3</li> </ul> <script> // query /* HTMLCollection --元素節點 NodeList */ var lis = document.querySelectorAll(".one"); console.log(lis); for(var i = 0;i < lis.length;i++){ lis[i].onclick = function(){ for(let i = 0;i<lis.length;i++){ lis[i].style.color="#333"; } this.style.color="#54bb47"; } } </script> ~~~