singles php design pattern Singleton singleton pattern

Copy code The code is as follows:

/**
* Singleton pattern
*
* Ensures that a class has only one instance and provides a global access point to access it
*
*/
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(); // The declaration cannot succeed
$obj = Singleton::getInstance();
var_dump($obj );
$obj->display();
$obj1 = Singleton::getInstance();
var_dump(($obj === $obj1));

The above introduces the singles PHP design pattern Singleton singleton mode, including the content of singles. I hope it will be helpful to friends who are interested in PHP tutorials.