求大佬看一下
运行不出来😓
<!DOCTYPE html>
<html>
<head>
<title> 事件</title>
<script type="text/javascript">
function count(){
var a=parseInt(document.getElementById("txt1").value);
var b=parseInt(document.getElementById("txt2").value);
var c=document.getElementById("select").value;
var result="";
switch(c){
case "+":result=a+b;
break;
case "-":result=a-b;
break;
case "*":result=a*b;
break;
case "/":result=a/b;
default:break;
document.getElementById("fruit").value=result;
}
}
</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()"/>
<input type='text' id='fruit'/>
</body>
</html>
