Question

我正在尝试进行表单验证并使用php将验证后的数据存储在mysql数据库中。代码工作正常，因为它应该在验证过程后将表单数据保存在mysql数据库中。问题是它显示未定义这些行中的索引错误
1。* <?php echo $error['name'];?>
2。* <?php echo $error['email']; ?>
3。<?php echo $error['website']; ?>
4。* <?php echo $error['gender'];?>。

这是我的完整代码。

<!DOCTYPE HTML>
 <html>
 <head>
<style>
.error {color: #FF0000;}
</style>
</head>
<body>

<?php
// define variables and set to empty values
$error=array();
$name = $email = $gender = $comment = $website = $data = "";
function test_input($data)
{

 $data = htmlspecialchars($data);
 return $data;
}
if ($_SERVER["REQUEST_METHOD"] == "POST")
{
if (empty($_POST["name"]))
 {$error['name']= "Name is required";}
else
 {
 $name = test_input($_POST["name"]);
 // check if name only contains letters and whitespace
 if (!preg_match("/^[a-zA-Z ]*$/",$name))
   {
   $error['name'] = "Only letters and white space allowed";
   }
 }

 if (empty($_POST["email"]))
 {$error['email'] = "Email is required";}
 else
 {
 $email = test_input($_POST["email"]);
 // check if e-mail address syntax is valid
 if (!preg_match("/([\w\-]+\@[\w\-]+\.[\w\-]+)/",$email))
   {
   $error['email'] = "Invalid email format";
   }
 }

 if (empty($_POST["website"]))
 {$website = "";}
 else
 {
 $website = test_input($_POST["website"]);
 // check if URL address syntax is valid 
 (this regular expression also allows dashes   in the URL)
 if (!preg_match("/\b(?:(?:https?|ftp):\/\/|www\.)
 [-a-z0-9+&@#\/%?=~_|!:,.;]*[-a-z0-9+&@#\/%=~_|]/i",$website))
   {
   $error['website'] = "Invalid URL";
   }
 }

if (empty($_POST["comment"]))
 {$comment = "";}
else
 {$comment = test_input($_POST["comment"]);}

if (empty($_POST["gender"]))
 {$error['gender'] = "Gender is required";}
else
 {$gender = test_input($_POST["gender"]);}
}

?>
<form method="post" action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]);?>">
Name: <input type="text" name="name" value="<?php echo $name;?>">
<span class="error">* <?php echo $error['name'];?></span>
<br><br>
E-mail: <input type="text" name="email" value="<?php echo $email;?>">
<span class="error">* <?php echo $error['email']; ?></span>
<br><br>
Website: <input type="text" name="website" value="<?php echo $website;?>">
<span class="error"><?php echo $error['website']; ?></span>
<br><br>
Comment: <textarea name="comment" rows="5" cols="40"><?php echo $comment;?></textarea>
<br><br>
Gender:
<input type="radio" name="gender" 
<?php if (isset($gender) &&  $gender=="female") 
echo "checked";?>    value="female">Female
<input type="radio" name="gender" 
<?php if (isset($gender) && $gender=="male") echo   "checked";?>  value="male">Male
<span class="error">* <?php echo $error['gender'];?></span>
<br><br>
<input type="submit" name="submit" value="Submit">
</form>
<?php
$con=mysqli_connect("localhost","root","root","my_db");
// Check connection
if (mysqli_connect_errno())
{
 echo "Failed to connect to MySQL: " . mysqli_connect_error();
 }

$sql="INSERT INTO np_appoint (Name,Email,Website,Comment,Gender)
VALUES


('$_POST[Name]','$_POST[Email]','$_POST[website]','$_POST[Comments]','$_POST[Gender]')";

if (!mysqli_query($con,$sql))
 {
 die('Error: ' . mysqli_error($con));
}
echo "1 record added";

mysqli_close($con);
?> 
</body>
</html>

Answer 1

要避免未定义的值，请使用isset().

<span class="error"> <?php if(isset($error['name']))
echo $error['name'];?></span>

Answer 2

因为如果没有错误，则$error数组未定义。

尝试在代码的开头定义代码＆gt;

$error['name'] = '';
$error['email'] = '';
$error['website'] = '';
$error['gender'] = '';

Answer 3

您的错误消息一次设置一个，但$error数组中的键未预定义。因此，如果名称有效，您将不会拥有$error['name']。这将产生一个未定义的索引NOTICE。

Answer 4

尝试访问尚未定义的数组键与访问任何其他未定义的变量相同，会产生E_NOTICE级错误消息，如undefined index

试试这个count($error)>0

 <?php if(count($error)>0){?>
   <span class="error">* <?php echo $error['name'];?></span>
<?php } ?>

OR

您可以使用foreach

<?php foreach($error as $value){?>
   <span class="error">* <?php echo $value;?></span>
<?php } ?>

Answer 5

USe isset（）函数

<span class="error">* <?php if(isset($error['name']))
echo $error['name'];?></span>

或使用@（不推荐）

的错误

<span class="error">* <?php   echo @$error['name'];?></span>

即使代码工作正常，也会发生未定义的索引错误

5 个答案: