是哪里出错了？为什么当前行号是空值？

Question

//1.js

var action="<a href=# onclick=deleterow(this)>删除</a> <a href=# onclick=modify(this)>修改</a>"
var selme="<input type=checkbox name=sme onclick=selectMe()>";  //选择框
var title=new Array("选择","学号","姓名","性别","年龄","操作");//单元格标题
var selall="<input type=checkbox id=sall onclick=selectAll()>"; 
var sall=new Array(selall,"全部选择");
var student=new Array();
student[0]=new Array(selme,"0817","zhangqiling","男","180",action);
student[1]=new Array(selme,"0305","wuxie","男","40",action);
student[2]=new Array(selme,"0187","heixiazi","男","180",action);
var oldvalue;//将原有数据保存起来
//输出表格
document.write("<table border=2 align='center' rules=all id=student");
document.write("<tr>");   //单元格标题开始
for(var i=0;i<title.length;i++)
{
    document.write("<th>"+title[i]+"</th>");   //th为单元格标题
}
document.write("</tr>");    //单元格标题结束
document.write("<tr>");        //输出全选一行
document.write("<th>"+sall[0]+"</th>");
document.write("<th>"+sall[1]+"</th>");
document.write("</tr>");
for(var r=0;r<student.length;r++)
{
    document.write("<tr>");        //每输出一行换行
    for(var c=0;c<student[r].length;c++)
    {
        document.write("<th>"+student[r][c]+"</th>");
    }
    document.write("</tr>");
}
document.write("</table>");   //表格结束
function selectAll()
{
    var selall=document.getElementById("sall");
    var selme=document.getElementsByName("sme");
    //判断有没有选中
    if(selall.checked)
    {
        for(var i=0;i<selme.length;i++)
        {
            selme[i].checked=true;
        }
    }
    else
    {
        for(var i=0;i<selme.length;i++)
        {
            selme[i].checked=false;
        }
    }
}
function selectMe()
{
    var selme=document.getElementsByName("sme");
    var selall=document.getElementById("sall");
    var flag;
    for(var j=0;j<selme.length;j++)
    {
        if(!selme[j].checked)
        {
            flag=false;
            break;
        }
        flag=true;
    }
    selall.checked=flag;
}
function deleterow(that)
{
    var curRow=that.parentNode.parentNode.rowindex;
    var ObjTable=document.getElementById("student");
    if(confirm("是否确认删除该行数据"))
    {
        ObjTable.deleteRow(curRow);
    }
}
function modify(that)
{
    var tdstr="<a href=# onclick=save(this)>保存</a> ";
    tdstr+="<a href=# onclick=cancel(this)>取消</a>";
    var curRowIndex=that.parentNode.parentNode.rowIndex; //获取当前行号
    var ObjTable=document.getElementById("student");
    var ObjTr=ObjTable.rows[curRowIndex];   //通过行序号获得当前行对象
    var myTd5=ObjTr.cells.item(4);            //年龄单元格
    alert(curRowIndex);
    alert(myTd5);
}

Answer 1

首先打印一下ObjTable，看看这个对象里有没有rows这个属性。
如果有，你试试ObjTable['rows'][curRowIndex];这种方式取值。