<!DOCTYPE HTML>
<html>
<head>
<style>
.error {
color: #FF0000;
}
</style>
</head>
<body>
<?php
// 定义变量并设置为空值
$nameErr = $emailErr = $genderErr = $websiteErr = null;
$name = $email = $gender = $comment = $website = null;
if ($_SERVER ["REQUEST_METHOD"] == "POST")
{
if (empty ( $_POST ["name"] ))
{
$nameErr = "姓名是必填的";
}
else
{
$name = test_input ( $_POST ["name"] );
// 检查姓名是否包含字母和空白字符
if (! preg_match ( "/^[a-zA-Z ]*$/", $name ))
{
$nameErr = "只允许字母和空格";
}
}
if (empty ( $_POST ["email"] ))
{
$emailErr = "电邮是必填的";
}
else
{
$email = test_input ( $_POST ["email"] );
// 检查电子邮件地址语法是否有效
if (! preg_match ( "/([w-]+@[w-]+.[w-]+)/", $email ))
{
$emailErr = "无效的 email 格式";
}
}
if (empty ( $_POST ["website"] ))
{
$website = "";
}
else
{
$website = test_input ( $_POST ["website"] );
// 检查 URL 地址语法是否有效（正则表达式也允许 URL 中的斜杠）
if (! preg_match ( "/(?:(?:https?|ftp)://|www.)[-a-z0-9+&@#/%?=~_|!:,.;]*[-a-z0-9+&@#/%=~_|]/i", $website ))
{
$websiteErr = "无效的 URL";
}
}
if (empty ( $_POST ["comment"] ))
{
$comment = "";
}
else
{
$comment = test_input ( $_POST ["comment"] );
}
if (empty ( $_POST ["gender"] ))
{
$genderErr = "性别是必选的";
}
else
{
$gender = test_input ( $_POST ["gender"] );
}
}
function test_input($data)
{
$data = trim ( $data );
$data = stripslashes ( $data );
$data = htmlspecialchars ( $data );
return $data;
}
?>
<h2>PHP 验证实例</h2>
<p>
<span class="error">* 必需的字段</span>
</p>
<form method="post" action="<?php echo htmlspecialchars($_SERVER[" PHP_SELF "]);?>">
姓名：
<input type="text" name="name"><span class="error">* <?php echo $nameErr;?></span>
<br>
<br> 电邮：
<input type="text" name="email"><span class="error">* <?php echo $emailErr;?></span>
<br>
<br> 网址：
<input type="text" name="website"><span class="error"><?php echo $websiteErr;?></span>
<br>
<br> 评论：
<textarea name="comment" rows="5" cols="40"></textarea>
<br>
<br> 性别：
<input type="radio" name="gender" value="female">女性
<input type="radio" name="gender" value="male">男性 <span class="error">* <?php echo $genderErr;?></span>
<br>
<br>
<input type="submit" name="submit" value="提交">
</form>
<?php
echo "<h2>您的输入：</h2>";
echo $name;
echo "<br>";
echo $email;
echo "<br>";
echo $website;
echo "<br>";
echo $comment;
echo "<br>";
echo $gender;
?>
</body>
</html>