我有一个正在扩展的基类，但我不明白为什么我在基类中定义的变量不能被子类访问。我知道他们必须受到保护才能允许访问，但他们仍然不适合我
class user {
protected static $username;
protected static $password;
protected static $remember;
function __construct() {
}
public function login($username, $password, $remember) {
$this->username = $username;
$this->password = $password;
$this->remember = $remember;
$login = new login();
}
}
class login extends user {
function __construct() {
print("user is: " . $this->username);
die();
}
}
基类中的变量是静态的，可以更好地理解继承。
你需要这个：
class user {
protected $username;
protected $password;
protected $remember;
public function __construct($username, $password, $remember) {
$this->username = $username;
$this->password = $password;
$this->remember = $remember;
}
}
class login extends user {
public function __construct($username, $password, $remember) {
parent::__construct($username, $password, $remember);
print("user is: " . $this->username);
}
}
$user = new login('joe bloggs', 'a password', TRUE);
因为变量应该是非静态的。如果你想要静态变量（就像你所知道的），它应该看起来像
print("user is: " . self::$username);
这将更有意义：
class user {
protected $username;
protected $password;
protected $remember;
public function __construct($username, $password, $remember) {
$this->username = $username;
$this->password = $password;
$this->remember = $remember;
}
public static function login($username, $password, $remember) {
return new login($username, $password, $remember);
}
}
class login extends user {
public function __construct($username, $password, $remember) {
parent::__construct($username, $password, $remember);
print("user is: " . $this->username);
die();
}
}
$foo = new user::login('foo', 'bar', 'meh');