<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<button>按钮1</button>
<button>按钮2</button>
<button>按钮3</button>
<button>按钮4</button>
<button>按钮5</button>
<script>
var btns = document.querySelectorAll('button');
for(var i = 0;i < btns.length; i++){
btns[i].onclick = function() { //按钮绑定循环事件
//（1）我们先把所有的背景颜色去掉
for(var i = 0 ; i<btns.length ; i++)
{
btns[i].style.backgroundColor = '';
}
//（2）然后才让当前元素背景颜色为pink
this.style.backgroundColor = 'pink';
}
}
</script>
</body>
</html>