PHP を使用してフォーム検証と小さなプログラムの送信処理を開発する

<?php
// 定义错误数组
$errors = [];

// 判断表单是否提交
if ($_SERVER["REQUEST_METHOD"] == "POST") {
    // 验证姓名
    if (empty($_POST["name"])) {
        $errors["name"] = "姓名不能为空！";
    } else {
        $name = $_POST["name"];
    }

    // 验证邮箱
    if (empty($_POST["email"])) {
        $errors["email"] = "邮箱不能为空！";
    } elseif (!filter_var($_POST["email"], FILTER_VALIDATE_EMAIL)) {
        $errors["email"] = "邮箱格式不正确！";
    } else {
        $email = $_POST["email"];
    }

    // 验证手机号
    if (empty($_POST["phone"])) {
        $errors["phone"] = "手机号不能为空！";
    } elseif (!preg_match("/^1[34578]d{9}$/", $_POST["phone"])) {
        $errors["phone"] = "手机号格式不正确！";
    } else {
        $phone = $_POST["phone"];
    }
}

?>

<form method="post" action="<?php echo $_SERVER["PHP_SELF"]; ?>">
    <div>
        <label for="name">姓名：</label>
        <input type="text" id="name" name="name" value="<?php echo $name ?? ''; ?>">
        <?php echo $errors["name"] ?? ''; ?>
    </div>
    <div>
        <label for="email">邮箱：</label>
        <input type="email" id="email" name="email" value="<?php echo $email ?? ''; ?>">
        <?php echo $errors["email"] ?? ''; ?>
    </div>
    <div>
        <label for="phone">手机号：</label>
        <input type="tel" id="phone" name="phone" value="<?php echo $phone ?? ''; ?>">
        <?php echo $errors["phone"] ?? ''; ?>
    </div>
    <button type="submit">提交</button>
</form>

<?php
if ($_SERVER["REQUEST_METHOD"] == "POST") {
    $name = $_POST["name"];
    $email = $_POST["email"];
    $phone = $_POST["phone"];

    // 对数据进行过滤和转义
    $name = filter_var($name, FILTER_SANITIZE_STRING);
    $email = filter_var($email, FILTER_SANITIZE_EMAIL);
    $phone = filter_var($phone, FILTER_SANITIZE_NUMBER_INT);

    // 进行数据库存储或其他操作
    // ...

    // 跳转到成功页面
    header("Location: success.php");
    exit;
}
?>