Question

我是PHP新手。我正在为简单的Cuboid计算器编写代码。如果长度，宽度和高度为负，为空或不是数字，则必须显示错误消息。

我尝试了以下代码。当长度字段输入不正确时，它会显示出不确定的错误，包括错误和错误。

<?php
//get the data from form
$length = $_GET['length'];
$breadth=$_GET['breadth'];
$height=$_GET['height'];
//calculate volume and tsa
if($length <=0 || empty($length) || !is_numeric($length) ){
    $errlength = "You must enter valid length greater than zero";
    $volume = '';
    $tsa = '';

}
else if($breadth <=0 || empty($breadth) || !is_numeric($breadth) ){
    $errbreadth= "You must enter valid length greater than zero";
    $volume = '';
    $tsa = '';
}
else if($height <=0 || empty($height) || !is_numeric($height) ){
    $errheight = "You must enter valid length greater than zero";
    $volume = '';
    $tsa = '';
}
else{
$volume = $length*$breadth*$height;
$tsa = 2*($length*$breadth + $breadth*$height + $height*$length);
}
if(!empty($volume) || !empty($tsa))
{
    $errlength='';
    $errbreadth='';
    $errheight='';
}
     ?>


HTML>>
<html>
 <body>
     <form action = "cuboid.php" method= "get">
       Length<input type="text" name="length">
         Breadth<input type="text" name="breadth">
         Height<input type="text" name="height">
    <input type="submit" name="Volume" value="Volume">
         <input type="submit" name="TSA" value="TS">
     </form>
     <h1>Cuboid Volume Calculator</h1>
<label>Length: </label>
<span><?php echo $length?></span><span><?php echo $errlength?></span><br>
<label>Breadth: </label>
<span><?php echo $breadth?></span><span><?php echo $errbreadth?></span><br>
<label>Height: </label>
<span><?php echo $height?></span><span><?php echo $errheight?></span><br>
<label>Volume: </label>
<span><?php echo $volume?></span><br>
<label>Total Surface Area: </label>
<span><?php echo $tsa?></span><br>

 </body>
</html>

我的代码怎么了？

Answer 1

从未设置$errlength，$errbreadth和$errheight的可能性。您可以通过将以下代码添加到PHP文件顶部来解决此问题：

$errlength='';
$errbreadth='';
$errheight='';

您也可以检查是否设置了这些变量，例如上面的@Jeff所说的，但是当我知道要使用哪种类型时，我个人比较舒服。

希望这会有所帮助，

PHP中未定义的变量，怎么了？

1 个答案: