<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>作业5-2</title>
</head>
<body>
<div id="list1">
第一章
</div>
<button onclick="add()">添加章节</button>
<button onclick="del()">删除章节</button>
<script>
var i=1;
var addch1=document.getElementById("addch1");
var list1=document.getElementById("list1");
1
function add(obj){
var parent=obj.parentNode;
var s="   第"+i+"节";
var node=document.createElement("div");
node.innerHTML=s;
parent.appendChild(node);
i++;
event.stopPropagation();
node.appendChild(parentNode)
addch1.appendChild(node)
}
function del(obj){
var parent=obj.parentNode;
parent.removeChild(parent.childNodes[parent.childNodes.length-1]);
i--;
}
</script>
</body>
</html>
```javascript
```