<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
<script type="text/javascript">
function empty(){
document.getElementById("select").options.length=0;
}
function delete(index){
document.getElementById("select").options.remove(index);
}
function add(){
var value=document.getElementById("select")
alert("添加第"+value.length+"个值是"+"刘六");
value.options[value.length] = new Option("刘六");
}
</script>
</head>
<body>
<select id="select" name="select">
<option value="0">请选择人员</option>
<option value="1">王五</option>
</select>
<br />
<input type="button" onClick="add()" value="添加"/>
<input type="button" onClick="delete(1)" value="删除第一个"/>
<input type="button" onClick="empty()" value="清空"/>
</body>
</html>
两个问题：
1.onClick属性应该写成onclick，在React中才是onClick
2.不能自定已定义delete函数，因为delete是保留关键字
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
<script type="text/javascript">
function empty(){
document.getElementById("select").options.length=0;
}
function delete1(index){
document.getElementById("select").options.remove(index);
}
function add(){
var value=document.getElementById("select")
alert("添加第"+value.length+"个值是"+"刘六");
value.options[value.length] = new Option("刘六");
}
</script>
</head>
<body>
<select id="select" name="select">
<option value="0">请选择人员</option>
<option value="1">王五</option>
</select>
<br />
<input type="button" onclick="add()" value="添加"/>
<input type="button" onclick="delete1(1)" value="删除第一个"/>
<input type="button" onclick="empty()" value="清空"/>
</body>
</html>