<html>
<head>
<title> 事件</title>
<script type="text/javascript">
function count(){
var a=document.getElementById("text1").value;
//获取第一个输入框的值
var b=document.getElementById("text2").value;
//获取第二个输入框的值
var select=document.getElementById("select").value;
//获取选择框的值
//获取通过下拉框来选择的值来改变加减乘除的运算法则
//设置结果输入框的值
var a;
switch(select){
case"+":
d=parseInt(a)+parseInt(b);
break;
case"-":
d=parseInt(a)-parseInt(b);
break;
case"*":
d=parseInt(a)*parseInt(b);
break;
case"/":
d=parseInt(a)/parseInt(b);
break;
}
document.getElementById("fruit").value=d;
}
</script>
</head>
<body>
<input type='text' id='txt1' />
<select id='select'>
<option value='+'>+</option>
<option value="-">-</option>
<option value="*">*</option>
<option value="/">/</option>
</select>
<input type='text' id='txt2' />
<input type='button' value=' = ' onclick="count()"/> <!--通过 = 按钮来调用创建的函数，得到结果-->
<input type='text' id='fruit' />
</body>
</html>
数据分析师2017-09-30 23:22:43
Master, see why this cannot be executed - PHP Chinese website Q&A - Master, see why this cannot be executed - PHP Chinese website Q&A
Take a look around and learn.
