OOP public variable problem

Can someone please help for some reason i can echo and set the file and department variables in my export function but when i try to call them in exportdata they are null.

Class customersController Extends baseController {
    public $file;
    public $department;


    public function export() {
        $this->registry->template->title = 'Ainsworthstudio - Export Customer Info';

        $this->registry->model->createModel('db', 'db');
        $this->registry->model->createModel('customers', 'customers');
        $this->registry->model->getModel('db')->addConnection("localhost", "sdgsdg", "sdg0", "sdg");
        $data = $this->registry->model->getModel('customers')->getDepartments();

        while(list($k, $v)=each($data))
            $$k = $v;

        $this->registry->template开发者_如何学Go->departments = $data;
        $this->registry->template->show('customers_export');
    }

    public function exportcheck() {
        if(!empty($_POST['filename'])) {
            $this->file =  $_POST['filename'];
            $this->department =  $_POST['depart'];

            echo "<div class='error_message'>Exported Successfully</div>";

            echo $this->file;
            echo $this->department;
            echo 'success';
        } else {
            echo "<div class='error_message'>Wrong Username or Password</div>";
            exit();
        }
    }

    public function exportdata() {
        return $this->file;
        return $this->department;

        echo $this->department;
    }
}

Your problem is here:

public function exportdata() {
    return $this->file;
    return $this->department;

    echo $this->department;
}

You're returning the value of $this->file not echoing.

If you try echo $myCustomersController->exportdata() you'll see it echo the value of $this->file

If you want to echo the values remove the returns

public function exportdata() {
    echo $this->file;
    echo $this->department;
}