案例：表格隔行变色(鼠标划过背景色恢复)
<!DOCTYPE html>
<html>
<head lang="en">
<meta charset="UTF-8">
<title></title>
<style>
* {
padding: 0;
margin: 0;
}
.wrap {
width: 500px;
margin: 100px auto 0;
}
table {
border-collapse: collapse;
border-spacing: 0;
border: 1px solid #c0c0c0;
width: 500px;
cursor: pointer;
}
th,
td {
border: 1px solid #d0d0d0;
color: #404060;
padding: 10px;
text-align: center;
}
th {
background-color: #09c;
font: bold 16px "微软雅黑";
color: #fff;
}
td {
font: 14px "微软雅黑";
}
tbody tr {
background-color: pink;
}
</style>
</head>
<body>
<div class="wrap">
<table>
<thead>
<tr>
<th>序号</th>
<th>姓名</th>
<th>课程</th>
<th>成绩</th>
</tr>
</thead>
<tbody id="j_tb">
<tr>
<td>
1
</td>
<td>柳岩</td>
<td>语文</td>
<td>100</td>
</tr>
<tr>
<td>
2
</td>
<td>苍老师</td>
<td>日语</td>
<td>100</td>
</tr>
<tr>
<td>
3
</td>
<td>凤姐</td>
<td>营销学</td>
<td>100</td>
</tr>
<tr>
<td>
4
</td>
<td>芙蓉姐姐</td>
<td>数学</td>
<td>10</td>
</tr>
<tr>
<td>
5
</td>
<td>佐助</td>
<td>英语</td>
<td>100</td>
</tr>
<tr>
<td>
6
</td>
<td>卡卡西</td>
<td>体育</td>
<td>100</td>
</tr>
<tr>
<td>
7
</td>
<td>乔峰</td>
<td>体育</td>
<td>100</td>
</tr>
</tbody>
</table>
</div>
<script src="common.js"></script>
<script>
//获取所以的行
var trs = my$("j_tb").getElementsByTagName("tr");
for (var i = 0; i < trs.length; i++) {
trs[i].style.backgroundColor = i % 2 == 0 ? "white" : "skyblue";
//鼠标进入
trs[i].onmouseover = mouseoverHandle;
//鼠标离开
trs[i].onmouseout = mouseoutHandle;
}
//鼠标进入的时候，先把设置后的颜色保存，等到鼠标离开再恢复即可
var lastColor = "";
function mouseoverHandle() {//鼠标进入
lastColor = this.style.backgroundColor;
this.style.backgroundColor = "pink";
}
function mouseoutHandle() {//鼠标进入
this.style.backgroundColor = lastColor;
}
</script>
</body>
</html>