Error calling model from controller in magento 2

Question

I have a controller and I want to call specific function of model from controller file, When I try to call function, I got an error like this :

Fatal error: Uncaught TypeError: Argument 2 passed to Lime\Hello\Controller\Index\Index::__construct() must be an instance of Lime\Hello\Model\Sync, instance of Magento\Framework\View\Result\PageFactory given, called in

here's my controller file code:

namespace Lime\Hello\Controller\Index;

use Magento\Framework\App\Action\Context;

class Index extends \Magento\Framework\App\Action\Action
{

    protected $_sync;
    public function __construct(\Magento\Framework\App\Action\Context $context, \Lime\Hello\Model\Sync $sync)
    {

        $this->_sync = $sync;
        parent::__construct($context);
    }


    public function execute()
    {
        $run = $this->_sync;
        echo $run->test();
        exit; 
    }
}

here's my model file code:

namespace Lime\Hello\Model;
use Magento\Framework\Object;

class Sync extends Object
{
  public function test(){
    return 'a';
  } 
}

Answer 1

Change construct of your model as below

public function __construct(\Magento\Framework\App\Action\Context $context, \Lime\Hello\Model\SyncFactory $sync)
    {

        $this->_sync = $sync;
        parent::__construct($context);
    }

Change below execute method code

public function execute()
    {
        $run = $this->_sync->create();
        echo $run->test();
        exit; 
    }

I have added create() in above code