1.表单验证实例
<html>
<head>
<meta charset="UTF-8">
</head>
<body>
<?php
$nameErr = $emailErr = $genderErr = $websiteErr = ""; //定义接受的数据
$name = $email = $gender = $comment = $website = ""; //定义返回的错误数据
if ($_SERVER["REQUEST_METHOD"] == "POST") { //检查发送方式是否为post
if (empty($_POST["name"])) { //是否为空
$nameErr = "姓名是必填的";
} else {
$name = test_input($_POST["name"]); //把接受到的数据进行修改
// 检查姓名是否包含字母和空白字符
if (!preg_match("/^[a-zA-Z ]*$/",$name)) { //正则表达式,对数据进行对比
$nameErr = "只允许字母和空格";
}
}
if (empty($_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("/\b(?:(?: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); // trim() 函数去除用户输入数据中不必要的字符 (如:空格,tab,换行)
$data = stripslashes($data); //stripslashes()函数去除用户输入数据中的反斜杠 (\)
$data = htmlspecialchars($data); //htmlspecialchars() 把一些预定义的字符转换为 HTML 实体
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>