<html> <head> <title> php实现简单计算器 </title> <meta http-equiv="content-type" content="text/html;charset=utf-8"> </head> <?php if(isset($_get["sub"])){ $sum=0; $num1=true; $num2=true; $numa=true; $numb=true; $message=""; if($_get["num1"]==""){ $num1=false; $message="第一个参数为空"; } if($_get["num2"]==""){ $num2=false; $message="第二个参数为空"; } if(!is_numeric($_get["num1"])){ $numa=false; $message.="第一个参数不是数字!"; } if(!is_numeric($_get["num2"])){ $numb=false; $message.="第二个参数不是数字!"; } if($num1 && $num2 && $numa){ switch($_get["ysf"]){ case "+":$sum=$_get["num1"]+$_get["num2"]; break; case "-":$sum=$_get["num1"]-$_get["num2"]; break; case "*":$sum=$_get["num1"]*$_get["num2"]; break; case "/":$sum=$_get["num1"]/$_get["num2"]; break; case "%":$sum=$_get["num1"]%$_get["num2"]; break; } } } ?> <body> <table align="center" border="1" width="500"> <caption><h1>计算器</h1></caption> <form action="jsq.php"> <tr> <td> <input type="text" size="5" name="num1" value="<?php echo $_get["num1"]?>"> </td> <td> <select name="ysf"> <option value="+" <?php echo $_get["ysf"]=="+"? "selected":""?>>+</option> <option value="-" <?php echo $_get["ysf"]=="-"? "selected":""?>>-</option> <option value="*" <?php echo $_get["ysf"]=="*"? "selected":""?>>*</option> <option value="/" <?php echo $_get["ysf"]=="/"? "selected":""?>>/</option> <option value="%" <?php echo $_get["ysf"]=="%"? "selected":""?>>%</option> </select> </td> <td> <input type="text" size="5" name="num2" value="<?php echo $_get["num2"]?>"> </td> <td> <input type="submit" name="sub" value="计算"> </td> </tr> <?php if(isset($_get["sub"])){ echo '<tr><td colspan="5">'; if($num1 && $num2 && $numa&& $numb){ echo "结果是:".$_get["num1"]." ".$_get["ysf"]." ".$_get["num2"]." = ".$sum; }else{ echo $message; } echo '</td></tr>'; } ?> </form> </table> </body> </html>