类成员的访问方式和权限

＜?php 
   class Widget 
   { 
       private $name; 
       private $price; 
       private $id; 

       public function __construct($name, $price) 
       { 
           $this->name = $name; 
           $this->price = floatval($price); 
           $this->id = uniqid(); 
       } 
       //checks if two widgets are the same 检查两个widget是否相同 
       public function equals($widget) 
       { 
           return(($this->name == $widget->name)AND 
               ($this->price == $widget->price)); 
       } 
   } 
   $w1 = new Widget('Cog', 5.00); 
   $w2 = new Widget('Cog', 5.00); 
   $w3 = new Widget('Gear', 7.00); 

   //TRUE 
   if($w1->equals($w2)) 
   { 
       print("w1 and w2 are the same  
\n"); 
   } 

   //FALSE 
   if($w1->equals($w3)) 
   { 
       print("w1 and w3 are the same
\n"); 
   } 

   //FALSE, == includes id in comparison 
   if($w1 == $w2) //不等,因为ID不同 
   { 
       print("w1 and w2 are the same
\n"); 
   } 
?＞