<?php
header("content-type:text/html;charset=utf-8");session_start();?><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml" xml:lang="zh-CN" dir="ltr"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/><title>简单计算机</title></head><body><form action="test.php" method="post">第一个数<input type="text" value="" name="num1"><br />计算符号<select name="oper"><option value="+">+</option><option value="-">-</option><option value="*">*</option><option value="/">/</option></select><br />第二个数<input type="text" value="" name="num2"><br /><input type="submit" value="计算结果"><br /></form></body></html><?php$num1=$_POST['num1'];$num2=$_POST['num2'];$oper=$_POST['oper'];$rs=0;switch($oper){ case "+":$rs=$num1+$num2;break;case "-":$rs=$num1-$num2;break;case "*":$rs=$num1*$num2;break;case "/":$rs=$num1/$num2;break;default: echo "您输入的不正确";}$_SESSION['rs']=$rs;echo '计算结果为：'.$_SESSION['rs'];?>