php 디자인 모드 Singleton(단일 모드)

 
  
/** 
  
*      
  
* 
  
*            ,               
  
* 
  
*/ 
  
class Singleton 
  
{ 
  
static private $_instance = null; 
  
 
  
private function __construct() 
  
{ 
  
} 
  
 
  
static public function getInstance() 
  
{ 
  
if(is_null(self::$_instance)) { 
  
self::$_instance = new Singleton(); 
  
} 
  
return self::$_instance; 
  
} 
  
 
  
public function display() 
  
{ 
  
echo "it is a singlton class function"; 
  
} 
  
} 
  
 
  
// $obj = new Singleton(); //        
  
$obj = Singleton::getInstance(); 
  
var_dump($obj); 
  
$obj->display(); 
  
 
  
$obj1 = Singleton::getInstance(); 
  
var_dump(($obj === $obj1));