class User {
    public $name;
    public $email;

    public function __construct($name, $email) {
        $this->name = $name;
        $this->email = $email;
    }

    public function sayHi() {
        echo "hi! my name is ".$this->name;
    }
}

class SuperUser extends User{   //[extens User]--> Userのメンバー変数やメソッドを引き継ぐことができる。
    public function superSayHi() {
        echo "HHHiii! my email is ".$this->email;
    }
}

$bob = new SuperUser("bob", "dummy@dummybob.com");

$bob->superSayHi();

public $name;
protected $email;   //[protected]-- このクラス内でも、継承したサブクラス内でも使える

class User {
    public $name;
    protected $email;   //[protected]-- このクラス内でも、継承したサブクラス内でも使える

    public function __construct($name, $email) {
        $this->name = $name;
        $this->email = $email;
    }

    public function sayHi() {
        echo "hi! my name is [ ".$this->name." ] and email is [ ".$this->email." ]";
    }
}

class SuperUser extends User {   //[extens User]--> Userのメンバー変数やメソッドを引き継ぐことができる。
    public function superSayHi() {
        echo "HHHiii! my email is [ ".$this->email." ]";
    }
}

$bob = new SuperUser("bob", "bob@dummy.com");
$bob->sayHi();
$bob->superSayHi();