未定义变量：使用 __get 方法时 php 中的 user_created_date

Question

我尝试从另一个类创建对象并从第二个类访问它。对象已创建，当我使用第一个类打印对象时，它将打印。但是当我使用第二类并调用getter方法并尝试打印时，它会报错。

当我尝试在第二个类中创建第一个类的对象并尝试调用getter方法时，它会给出未定义变量$any_varible的错误。

头等舱：

<?php 
    namespace pages;
    class User { 
    private static $first_name; 
    private static $last_name;
    private static $nic;
    private static $email;
    private static $password;
    private static $tel;
    private static $address;
    private static $city;
    private static $postal_code;
    private static $dob;
    private static $food;
    private static $pet;
    private static $smoke;
    private static $chat;
    private static $music;
    private static $gender;
    private static $user_created_date;




    public function __construct($first_name,$last_name,$nic,$email,$password,$tel,$address,$city,$postal_code,$dob,$food,$pet,$smoke,$chat,$music,$gender,$user_created_date) {
        $this->$first_name=$first_name;
        $this->$last_name=$last_name;
        $this->$nic=$nic;
        $this->$email=$email;
        $this->$password=$password;
        $this->$tel=$tel;
        $this->$address=$address;
        $this->$city=$city;
        $this->$postal_code=$postal_code;
        $this->$dob=$dob;
        $this->$food=$food;
        $this->$pet=$pet;
        $this->$smoke=$smoke;
        $this->$chat=$chat;
        $this->$music=$music;
        $this->$gender=$gender;
        $this->$user_created_date=$user_created_date;


    } 
    public function __get($property) {
        if (property_exists($this, $property)) {
          return $this->$property;
        }
      }

     public function __set($property, $value) {
        if (property_exists($this, $property)) {
          $this->$property = $value;
        }

     }


} ?>


<?php
    namespace pages;
    include '../Model/User.php';
    include 'Database.php';
    {

        $cars = array(0,0,0,0,0);
        $availableChoice=$_POST['choice'];
        $today=date('Y/m/d');
        $count=0;
        foreach ($availableChoice as $name){
            $cars[$count]=1;
            $count++;
        }

        $usernew=new User($_POST['fName'],$_POST['lName'],$_POST['nic'],$_POST['email'],$_POST['password'],$_POST['mobile'],$_POST['address'],$_POST['city'],$_POST['postalCode'],$_POST['dob'],$cars[0],$cars[1],$cars[2],$cars[3],$cars[4],$_POST['gender'],$today);
        //echo $_POST['email'];
        //echo $user->$email;
        echo $usernew->__get($user_created_date);
        /*$newDatabase=new Database();
        $connection=$newDatabase->CreateConnection();
        $newDatabase->InsertUser($user,$connection);*/


    }


?>

Answer 1

尝试像这样更新你的 getter 和 setter：

public function __set($name, $value) {
    $this->data[$name] = $value;
}

public function __get($name) {
    if (array_key_exists($name, $this->data)) {
        return $this->data[$name];
    }
    return null;
}

http://php.net/manual/en/language.oop5.overloading.php#object.get

实际上试试这个..

class User { 

    private $data = array();

    public function __construct($data) {
        $this->data = $data;
    }

    public function __set($name, $value) {
        $this->data[$name] = $value;
    }

    public function __get($name) {
        if (array_key_exists($name, $this->data)) {
            return $this->data[$name];
        }
        return null;
    }

}

$u = new User($_POST);
echo $u->fName;

您必须确保将要传递给 User 类的所有数据添加到 $data 数组中。

您的 User 类可能应该传递一个 $id 而不是实际数据。使用 $id 来提取数据。更像这样：

class User { 

    private $data = array();

    public function __construct($id = null) {
        if (!is_null($id) && $id > 0) {
            $this->id = $id;
            $this->data = array(); # query user data..
        } else {
            $this->id = 0;
        }
    }

    public function __set($name, $value) {
        $this->data[$name] = $value;
    }

    public function __get($name) {
        if (array_key_exists($name, $this->data)) {
            return $this->data[$name];
        }
        return null;
    }

    public function save() {
        if ($this->id > 0) {
            # UPDATE user data..
        } else {
            # INSERT user data..
        }
    }

}

# add new user (no ID provided)..
$u = new User();
$u->fName = $_POST['fName'];
$u->lName = $_POST['lName'];
$u->save();

# get/update user data (ID provided)..
$u = new User(1);
echo $u->fName; # get
$u->fName = 'NewName'; # update
$u->save();