<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>事件</title>
<link href="css.css" rel="stylesheet" type="text/css"/>
</head> <body>
<div id="container">
<!DOCTYPE HTML>
<html >
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>数组</title>
<script type="text/javascript">
function count(){ //获取第一个输入框的值
var num1 = parseInt(document.getElementById("txt1").value);
var num2 = parseInt(document.getElementById("txt2").value);
var fu =document.getElementById("select").value;
var jisuan;
switch(fu)
{
case "+":jisuan= num1+num2;break;
case "-":jisuan= num1-num2;break;
case "*":jisuan= num1*num2;break;
case "/":jisuan= num1/num2;break;
default:break;
} document.getElementById("fruit").value = jisuan;
//获取第二个输入框的值
//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 }
</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>
</div> </body>
</html>