abstract：//thinkphp5.1中的單例模式class Demo{    private function __construct(){}    private function __clone(){}    protected static $instance=null; 

//thinkphp5.1中的單例模式

class Demo

{

    private function __construct(){}

    private function __clone(){}

    protected static $instance=null;

    public static function getConnect(){

       if(is_null(static::$instance)){

           static::$instance=new static();

         }

        return static::$instance;

     }

}

$connect=Demo::getConnect();

Correcting teacher：查無此人Correction time：2019-04-17 09:17:34
Teacher's summary：完成的不錯(cuò)。寫代碼要多寫點(diǎn)注釋，才方便別人查看。繼續(xù)加油。