如何在php中更新类对象中的值

Question

我有一个带有客户端构造函数的文件 user.php：

    class Client{
    public $name;
    public $pin;
    public $balance;

    function __construct($name, $pin, $balance){
        $this->name = $name;
        $this->pin = $pin;
        $this->balance = $balance;
    }
} 
$client1 = new Client("Alan", "0201", 2000);
                                                                                    
?>

我还有一个文件，我可以在其中对客户端对象进行一些数学运算：

$balance = $client1->balance;

function withdrow($amount, $balance){
    $currentBalance = $balance - $amount;
    if($balance < $amount){
        echo "You are low on balance";
    }
    else{
        $client1->balance = $currentBalance;
        return $currentBalance;
    }
}

还有第三个 html 文件，其中我在客户端包含第一个文件，我想在屏幕上回显余额的更新值。但它打印客户端中设置的值。如何更新余额。

我的代码现在看起来像这样，但是 setter 没有改变价值平衡：

class Client{
public $name;
private $pin;
private $balance;

function __construct($name, $pin, $balance){
    $this->name = $name;
    $this->pin = $pin;
    $this->balance = $balance;
}
private function setPin($pin){
     $this->pin = $pin;
  }
public function getPin(){
    return $this->pin;
  }

public function setBalance($balance){
     $this->balance = $balance;
  }

public function getBalance(){
    return $this->balance;
  }

} 

$client1 = new Client("Alan", "0201", 2000);
                                            

Answer 1

您必须通过引用调用来调用函数

function withdrow($amount, &$balance){ /** call by reference */ 
   $currentBalance = $balance - $amount;
   if($balance < $amount){
       echo "You are low on balance";
   }
   else{
       $client1->balance = $currentBalance;
       return $currentBalance;
   }
}