To get the Array request/input value in Joomla 3+

To get the Array request/input value in Joomla 2.5/3.0/3.4.3/3+

        // Initialise the global application object
        $this->main = JFactory::getApplication();

        // To get the an array of item from joomla input/request variable. 
        $cids = $this->main->input->get('cid', array(), 'ARRAY'); // 'ARRAY' or 'array'

        // To get the first item from the array;
        $cid = current($cids);