Contact Form 7 customize response message - [resolved]

If you want to change response message by code for contact form 7 than please write below code:

add_action("wpcf7_ajax_json_echo", "cf7_change_response_message",10,2);

function cf7_change_response_message($items, $result){
    /*
        Here you can write your custom code for response message
    */
}