php怎么保存表单信息到数组

<form method="POST" action="signup.php">    <label for="username">用户名：</label>    <input type="text" name="username" id="username">    <label for="email">电子邮箱：</label>    <input type="text" name="email" id="email">    <label for="password">密码：</label>    <input type="password" name="password" id="password">    <input type="submit" value="注册"></form>

<?php    // 处理提交的表单数据    $username = $_POST['username'];    $email = $_POST['email'];    $password = $_POST['password'];    // 将表单数据保存到数组中    $user_info = array(        'username' => $username,        'email' => $email,        'password' => $password    );    // 打印保存的数组信息    print_r($user_info);?>

Array (    [username] => user123    [email] => user123@domain.com    [password] => 123456)