Call multiple methods on object?

Class A{
    private $name;
    private $id;

    public function setName($name) {
        $this–>name = $name;
        return $this;
    }

    public function getName() {
        return $this–>name;
    }

    public function setId($id) {
        $this–>id = $id;
        return $this;
    }

    public function getId() {
        return $this–>id;
    }
}

$test = new A();
$test->setId(1)->setName('Fredrick');

class Test{
    function test(){
        return 'Hi!';
    }
}

class Test2{
    function test_2(){
        return new Test();
    }
}

class Test3{
    function test_3(){
        return new Test2();
    }
}

$obj = new Test3();
echo $obj->test_3()->test_2()->test();

class Test{
    private $num;
    function test(){
        return 'Hi! your number is: '.$this->num;
    }

    function test_2($mul){
        $this->num *= $mul;
        return $this;
    }

    function test_3($add){
        $this->num = $add;
        return $this;
    }
}

$obj = new Test();
echo $obj->test_3(50)->test_2(2)->test();