一个php计算器程序 寻错
<!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"><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8" /><html> <head> <title> 计算器</title></head><body> <?php if(isset($_POST["number1"])&&isset($_POST["number2"])) { if(empty($_POST["$number1"])&&empty($_POST["number2"])) { echo"操作数不能为空"; unset($_POST["sub"]); } else { $number1=$_GET["number1"]; $number2=$_GET["number2"]; $oper=$_GET["oper"]; } } ?> <?php if(isset($_GET["sub"])){ $sum=0; switch($oper){ case"+": $sum=$_GET["number1"]+$_GET["number2"]; break; case"-": $sum=$_GET["number1"]-$_GET["number2"]; break; case"x": $sum=$_GET["number1"]*$_GET["number2"]; break; case"/": if($numebr2=="0") echo"0不能为除数"; else $sum=$_GET["number1"]/$_GET["number2"]; break; } }?>
<center><h1>计算器</h1> <table border='1'><tr><td><form action="" method="get"> <input type="text" name="number1" value="<?php if(!empty($number1)) echo $number1; ?>"></td><td> <select name="oper"> <option value ="+">+</option> <option value ="-">-</option> <option value ="*">*</option> <option value ="\">\</option> </select></td> <td> <input type="text" name="number2"value="<?php if(!empty($number2)) echo $number2; ?>"></td> <td><input name="sub" type="submit" value="计算" /></td></tr> </center>
<?php if(isset($_GET["sub"])){ echo '<tr><td colspan="4">'; echo "结果：".$_GET["number1"]." ".$_GET["oper"]." ".$_GET["number2"]."=".$sum; echo '</td></tr>'; } ?></form> </table> </body></html>
