动态表格的添加和删除（优化简单写法）
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>动态表格</title>
<style>
table{
border: 1px solid;
margin: auto;
width: 500px;
}
td,th{
text-align: center;
border: 1px solid;
}
div{
text-align: center;
margin: 50px;
}
</style>
</head>
<body>
<div>
<input type="text" id="id" placeholder="请输入编号">
<input type="text" id="name" placeholder="请输入姓名">
<input type="text" id="gender" placeholder="请输入性别">
<input type="button" value="添加" onclick="addtr()">
</div>
<table id="tab">
<caption>学生信息表</caption>
<tr>
<th>编号</th>
<th>姓名</th>
<th>性别</th>
<th>操作</th>
</tr>
<tr>
<td>1</td>
<td>葫芦娃</td>
<td>男</td>
<td><a href="javascript:void (0)" onclick="deltr(this)">删除</a></td>
</tr>
<tr>
<td>2</td>
<td>爷爷</td>
<td>男</td>
<td><a href="javascript:void (0)" onclick="deltr(this)">删除</a></td>
</tr>
<tr>
<td>3</td>
<td>妖精</td>
<td>?</td>
<td><a href="javascript:void (0);" onclick="deltr(this)">删除</a></td>
</tr>
</table>
<script>
//添加一行的方法
function addtr() {
var tab = document.getElementById("tab");
var vid = document.getElementById("id").value;
var vname = document.getElementById("name").value;
var vgender = document.getElementById("gender").value;
//获取table
//var tab = document.getElementsByTagName("table")[0];
tab.innerHTML +="<tr>\n" +
" <td>"+vid+"</td>\n" +
" <td>"+vname+"</td>\n" +
" <td>"+vgender+"</td>\n" +
" <td><a href=\"javascript:void (0)\" onclick='deltr(this)'>删除</a></td>\n" +
" </tr>"
}
//删除一行的方法
function deltr(obj) {
//第一个爹是td,爷爷是tr，太爷是table
var tab = obj.parentNode.parentNode.parentNode;
//删除
tab.removeChild(obj.parentNode.parentNode);
}
</script>
</body>
</html>