Singleton Pattern Small Example

Header ("Content-type:text/html;charset=utf-8");
Final modifier class, the single class cannot inherit from the quilt class
Final class single{
Declaring a private static variable
private static $instance;

// 构造函数private function __construct(){}// 获取单例对象函数static public function getInstance(){    if(!is_null(self::$instance)){        return self::$instance;    }else{        return self::$instance = new Single();    }}// 禁止对象的克隆，clone关键字使用时会报错private function __clone(){}

}

$obj 1 = single::getinstance ();
Var_dump ($obj 1);

$obj 2 = single::getinstance ();
Var_dump ($obj 2);

There will be an error.
$obj 3 = Clone $obj 2;
Var_dump ($obj 3);

Singleton Pattern Small Example