/** * @author xiaojiang * 方式1 */class father{    static $models = [];    static public function getInstance(){        $name =  get_called_class();        if( !isset( self::$models[$name] ) ){            self::$models[$name] = new $name();        }        return self::$models[$name];    }        public function m1(){        echo "fm1";    }    public function m2(){        echo "fm2";    }}class child extends father{    public function m1(){        echo ‘cm1‘;    }}father::getInstance()->m1();child::getInstance()->m1();/** * 方式2 */ class base{    static protected  $ins = [];        static public function getInstance(){        $cName = get_called_class();        if( !isset(static::$ins[$cName]) ){            static::$ins[$cName] = new $cName;        }        return static::$ins[$cName];    }        public function m1(){        return "base m1";    }        public function m2(){        return "base m2";    }    }class cbase extends base{        //static public $ins = null;    static public function getInstance(){        return parent::getInstance();    }        public function m1(){        return "cbase m1<br>";    }    }echo base::getInstance()->m1()."<br>";echo cbase::getInstance()->m1();