未定义的变量和联系表中的错误 php

Question

我正在使用下面的代码向电子邮件发送简短说明。

我收到以下错误，我不明白为什么，

<?php echo "<p class='text-danger'>
                    $errName
                </p>
                ";?>

为什么会出现错误？

这里是完整的代码

<?php


if (isset($_POST['submit'])) {
$name = $_POST['name'];
$email = $_POST['email'];
$message = $_POST['message'];
$human = intval($_POST['human']);
$from = 'Demo Contact Form';
$to = 'example@domain.com';
$subject = 'Message from Contact Demo ';
$body ="From: $name\n E-Mail: $email\n Message:\n $message";
// Check if name has been entered


if (!$_POST['name']) {
$errName = 'Please enter your name';
}

// Check if email has been entered and is valid
if (!$_POST['email'] || !filter_var($_POST['email'], FILTER_VALIDATE_EMAIL)) {
$errEmail = 'Please enter a valid email address';
}
//Check if message has been entered
if (!$_POST['message']) {
$errMessage = 'Please enter your message';
}
//Check if simple anti-bot test is correct
if ($human !== 5) {
$errHuman = 'Your anti-spam is incorrect';
}
// If there are no errors, send the email
if (!$errName && !$errEmail && !$errMessage && !$errHuman) {
if (mail ($to, $subject, $body, $from)) {
$result='<div class="alert alert-success">Thank You! I will be in touch</div>';
} else {
$result='<div class="alert alert-danger">Sorry there was an error sending your message. Please try again later.</div>';
}
}
}

?>
<!DOCTYPE html>
<html lang="en">
<head>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.1/js/bootstrap.min.js"></script>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1">
<meta name="description" content="Bootstrap contact form with PHP example by BootstrapBay.com.">
<meta name="author" content="BootstrapBay.com">
<title>Bootstrap Contact Form With PHP Example</title>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.1/css/bootstrap.min.css">
</head>
<body>
<div class="container">
<div class="row">
<div class="col-md-6 col-md-offset-3">
<h1 class="page-header text-center">Contact Form Example</h1>
<form class="form-horizontal" role="form" method="post" action="index.php">
<div class="form-group">
<label for="name" class="col-sm-2 control-label">Name</label>
<div class="col-sm-10">
<input type="text" class="form-control" id="name" name="name" placeholder="First & Last Name" value="<?php if (isset($_POST['name'])){ echo htmlspecialchars($_POST['name']); } ?>">
<?php echo "<p class='text-danger'>$errName</p>";?>
</div>
</div>
<div class="form-group">
<label for="email" class="col-sm-2 control-label">Email</label>
<div class="col-sm-10">
<input type="email" class="form-control" id="email" name="email" placeholder="example@domain.com" value="<?php if (isset($_POST['email'])){ echo htmlspecialchars($_POST['email']); } ?>">
<?php echo "<p class='text-danger'>$errEmail</p>";?>
</div>
</div>
<div class="form-group">
<label for="message" class="col-sm-2 control-label">Message</label>
<div class="col-sm-10">
<textarea class="form-control" rows="4" name="message"><?php if (isset($_POST['message'])){ echo htmlspecialchars($_POST['message']); } ?></textarea>
<?php echo "<p class='text-danger'>$errMessage</p>";?>
</div>
</div>
<div class="form-group">
<label for="human" class="col-sm-2 control-label">2 + 3 = ?</label>
<div class="col-sm-10">
<input type="text" class="form-control" id="human" name="human" placeholder="Your Answer">
<?php echo "<p class='text-danger'>$errHuman</p>";?>
</div>
</div>
<div class="form-group">
<div class="col-sm-10 col-sm-offset-2">
<input id="submit"  type="submit"  name="submit" value="submit" class="btn btn-primary">
</div>
</div>
<div class="form-group">
<div class="col-sm-10 col-sm-offset-2">
<?php echo $result; ?>  
</div>
</div>
</form>
</div>
</div>
</div>

</body>
</html>

我真的很想找人帮忙如果有人能帮我的话会很有帮助

谢谢

Answer 1

您需要在 submit 之前加载时使用此处。第一次加载时，您应该将值声明为 $errName = '';

<?php
$errName = '';

if (isset($_POST['submit'])) {
$name = $_POST['name'];
$email = $_POST['email'];
$message = $_POST['message'];
$human = intval($_POST['human']);
$from = 'Demo Contact Form';
$to = 'example@domain.com';
$subject = 'Message from Contact Demo ';
$body ="From: $name\n E-Mail: $email\n Message:\n $message";
// Check if name has been entered


if (!$_POST['name']) {
$errName = 'Please enter your name';
}

// Check if email has been entered and is valid
if (!$_POST['email'] || !filter_var($_POST['email'], FILTER_VALIDATE_EMAIL)) {
$errEmail = 'Please enter a valid email address';
}
//Check if message has been entered
if (!$_POST['message']) {
$errMessage = 'Please enter your message';
}
//Check if simple anti-bot test is correct
if ($human !== 5) {
$errHuman = 'Your anti-spam is incorrect';
}
// If there are no errors, send the email
if (!$errName && !$errEmail && !$errMessage && !$errHuman) {
if (mail ($to, $subject, $body, $from)) {
$result='<div class="alert alert-success">Thank You! I will be in touch</div>';
} else {
$result='<div class="alert alert-danger">Sorry there was an error sending your message. Please try again later.</div>';
}
}
}

?>

Answer 2

您需要定义 $errName，例如 $errName=""，然后再提交，试试这个：

<?php
    $errName ="";
    $errMessage ="";
    $errHuman ="";
    $result="";
    $errEmail ="";
    if (isset($_POST['submit'])) {
    $name = $_POST['name'];
    $email = $_POST['email'];
    $message = $_POST['message'];
    $human = intval($_POST['human']);
    $from = 'Demo Contact Form';
    $to = 'example@domain.com';
    $subject = 'Message from Contact Demo ';
    $body ="From: $name\n E-Mail: $email\n Message:\n $message";
    // Check if name has been entered


    if (!$_POST['name']) {
    $errName = 'Please enter your name';
    }

    // Check if email has been entered and is valid
    if (!$_POST['email'] || !filter_var($_POST['email'], FILTER_VALIDATE_EMAIL)) {
    $errEmail = 'Please enter a valid email address';
    }
    //Check if message has been entered
    if (!$_POST['message']) {
    $errMessage = 'Please enter your message';
    }
    //Check if simple anti-bot test is correct
    if ($human !== 5) {
    $errHuman = 'Your anti-spam is incorrect';
    }
    // If there are no errors, send the email
    if (!$errName && !$errEmail && !$errMessage && !$errHuman) {
    if (mail ($to, $subject, $body, $from)) {
    $result='<div class="alert alert-success">Thank You! I will be in touch</div>';
    } else {
    $result='<div class="alert alert-danger">Sorry there was an error sending your message. Please try again later.</div>';
    }
    }
    }

    ?>

Answer 3

用这个替换相应的代码段。（类似情况调整）

if (isset($errName)) {
    echo '<p class="text-danger">'.$errName.'</p>';
}

请注意，在使用带单引号的 echo <p class='text-danger'>$errName</p> 的情况下，您需要将 $errName 与字符串的其余部分连接起来，否则它将被打印为“$errName”。

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