                        課程
                    
                        /前端開發(fā)
                        
                            /JavaScript
                        
                        /JavaScript進(jìn)階篇

刪除函數(shù)deleteRow()中，為什么要獲取到最后一個(gè)節(jié)點(diǎn)，不太明白。

<!DOCTYPE?html>
<html>
?<head>
??<title>?new?document?</title>??
??<meta?charset='utf-8'/>???
??<script?>??
?????window.onload?=?function(){
????????Highlight();
?????}??
?????function?addOne(obj){?
????????var?tbody?=?document.getElementById('table').lastChild;??
????????var?tr?=?document.createElement('tr');??
?????????
?????????var?td?=?document.createElement("td");
?????????td.innerHTML?=?"<input?type='text'/>";
?????????tr.appendChild(td);
?????????
?????????td?=?document.createElement("td");?????
?????????td.innerHTML?=?"<input?type='text'/>";
?????????tr.appendChild(td);
?????????
?????????td?=?document.createElement("td");????
?????????td.innerHTML?=?"<a?href='javascript:;'?onclick='deleteRow(this)'>刪除</a>";
?????????tr.appendChild(td);???
?????????
?????????tbody.appendChild(tr);???
????????Highlight();
????????}

?????function?deleteRow(obj){
????????var?tbody?=?document.getElementById('table').lastChild;//最后的節(jié)點(diǎn)不是空白節(jié)點(diǎn)嗎??
????????var?tr?=?obj.parentNode.parentNode;
?????????tbody.removeChild(tr);
?????}
?????function?Highlight(){
????????var?tbody?=?document.getElementById('table').lastChild;????
????????trs?=?tbody.getElementsByTagName('tr');???
????????for(var?i?=1;i<trs.length;i++){
????????????trs[i].onmouseover?=?function(){
????????????????this.style.backgroundColor?="#f2f2f2";
????????????}?
????????????trs[i].onmouseout?=?function(){
????????????????this.style.backgroundColor?="#fff";
????????????}?
????????}??
?????}

??</script>?
?</head>?
?<body>?
???????<table?border="1"?width="50%"?id="table">
???????<tr>
????????<th>學(xué)號(hào)</th>
????????<th>姓名</th>
????????<th>操作</th>
???????</tr>??

???????<tr>
????????<td>xh001</td>
????????<td>王小明</td>
????????<td><a?href="javascript:;"?onclick="deleteRow(this)">刪除</a></td>
???????</tr>

???????<tr>
????????<td>xh002</td>
????????<td>劉小芳</td>
????????<td><a?href="javascript:;"?onclick="deleteRow(this)">刪除</a></td>
???????</tr>??

???????</table>
???????<input?type="button"?value="添加一行"?onclick="addOne()"?/>
?</body>
</html>