下面的HTML段落，在书名和价格输入错误的情况下，无法进行修改。添加一个按钮，对已经输入的信息进行修改。
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
<style>
tr{
height: 60px;
}
td ,th{
width: 150px;
text-align: center;
border: 1px solid red;
}
</style>
<script>
function addNode(){
var tab = document.getElementById ("tab");
var tr = document.createElement("tr");
var td = document.createElement("td");
td.innerHTML = '<input type="Text"/ size="10px" οnblur="saveVal(this)" />';
var td2 = document.createElement("td");
td2.innerHTML = '<input type="Text" size="10px" οnblur="saveVal(this)" />';
var td3 = document.createElement("td");
td3.innerHTML = '<input type="button" value="添加" οnclick="addNode()" />'+
'<Input type="button" Value="删除" οnclick="removeNode(this)" />';
tab.appendChild(tr);
tr.appendChild(td);
tr.appendChild(td2);
tr.appendChild(td3);
}
function saveVal(thi){
var td =thi.parentNode;
td.innerText = thi.value;
}
function removeNode(abc){
var tr =abc.parentNode.parentNode;
tr.remove();
}
</script>
</head>
<body>
<table id="tab" border="1px" align="center">
<tr>
<th>图书名称</th>
<th>图书价格</th>
<th>操作</th>
</tr>
<tr>
<td>javaSE</td>
<td>19</td>
<td>
<input type="button" name="" id="" value="添加" οnclick="addNode()" />
<input type="button" name="" id="" value="删除" οnclick="removeNode(this)" />
</td>
</tr>
<tr>
<td>javaEE</td>
<td>29</td>
<td>
<input type="button" name="" id="" value="添加" οnclick="addNode()" />
<input type="button" name="" id="" value="删除" οnclick="removeNode(this)"/>
</td>
</tr>
</table>
</body>
</html>
修改后的段落如下：
<!DOCTYPE html>
<html><head><meta charset="utf-8"><title></title><style>tr{height: 60px;}td ,th{width: 150px;text-align: center;border: 1px solid red;}</style><script>function addNode(){var tab = document.getElementById ("tab");var tr = document.createElement("tr");var td = document.createElement("td");td.innerHTML = '<input type="Text"/ size="10px" οnblur="saveVal(this)" />';var td2 = document.createElement("td");td2.innerHTML = '<input type="Text" size="10px" οnblur="saveVal(this)" />';var td3 = document.createElement("td");td3.innerHTML = '<input type="button" value="添加" οnclick="addNode()" />'+'<input type="button" value="删除" οnclick="removeNode(this)" />'+'<input type="button" value="修改" οnclick="editNode(this)" />'; // 添加修改按钮tab.appendChild(tr);tr.appendChild(td);tr.appendChild(td2);tr.appendChild(td3);}function saveVal(thi){var td = thi.parentNode;td.innerText = thi.value;}function removeNode(abc){var tr = abc.parentNode.parentNode;tr.remove();}function editNode(btn) {var tr = btn.parentNode.parentNode;var tds = tr.getElementsByTagName('td');for (var i = 0; i < 2; i++) { // 前两列是书名和价格var td = tds[i];var value = td.innerText;td.innerHTML = '<input type="Text" size="10px" value="' + value + '" οnblur="saveVal(this)" />';}}</script></head><body><table id="tab" border="1px" align="center"><tr><th>图书名称</th><th>图书价格</th><th>操作</th></tr><tr><td>javaSE</td><td>19</td><td><input type="button" name="" id="" value="添加" οnclick="addNode()" /><input type="button" name="" id="" value="删除" οnclick="removeNode(this)" /><input type="button" name="" id="" value="修改" οnclick="editNode(this)" /> <!-- 添加修改按钮 --></td></tr><tr><td>javaEE</td><td>29</td><td><input type="button" name="" id="" value="添加" οnclick="addNode()" /><input type="button" name="" id="" value="删除" οnclick="removeNode(this)" /><input type="button" name="" id="" value="修改" οnclick="editNode(this)" /> <!-- 添加修改按钮 --></td></tr></table></body>
</html>
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