PHP變量未定義錯誤

Question

我有這個類（這是簡單的卡類）：

class Card{ 
private $suit; 
private $rank; 

public function __construct($suit, $rank){ 
    $this->$suit = $suit; 
    $this->$rank = $rank; 
} 

public function get_suit(){ 
    return $this->$suit; 
} 

public function get_rank(){ 
    return $this->$rank; 
} 
    } 

我實例的每個卡（帶花色和等級）爲甲板：

 $tmp_deck = array(); 
    foreach ($SUITS as $suit){ 
     foreach($RANKS as $rank){ 
      array_push($tmp_deck, new Card($suit, $rank)); 
     } 
    } 
    echo $tmp_deck[0]->get_suit(); 

和錯誤它給我：

Notice: Undefined variable: suit in card.php on line 13 

我真的不能得到什麼是錯的。誰能幫我 ？

Answer 1

類像$this->suit變量訪問不喜歡$this->$suit

改變這種

public function __construct($suit, $rank){ 
$this->$suit = $suit; 
$this->$rank = $rank; 
} 

到

public function __construct($suit, $rank){ 
    $this->suit = $suit; 
    $this->rank = $rank; 
} 

更改其他人。

Answer 2

更改$this->$suit到$this->suit，訪問類變量時不需要$。同爲$this->$rank - >$this->rank