class person{

    private $age;

    private $sex;

    public function __construct($age,$sex){

        $this->age=$age;

        $this->sex=$sex;

    }

    public function getage(){

        return $this->age;

    }

    public function getclosure(){

        return function() {

                return $this->age . "-->" . $this->sex;

            };

    }

}

$tom=new person(18,1);

$lucy=new person(16,2);

$set=Closure::bind(function($obj,$k,$v){

    $obj->$k=$v;

},null,person::class);

$get=Closure::bind(function($obj,$k){

    return $obj->$k;

},null,person::class);

$get_tom_age=Closure::bind(function() use($tom){

    return $tom->age;

},null,person::class);

echo $get_tom_age();//

echo $get($tom,'age');//

$set($tom,'age',20);

echo $get($tom,'age');//

$c1=$tom->getclosure();

echo $c1();//20-->1

$c1=$c1->bindTo($lucy);

echo $c1();//16-->2