Problem
Define a class named GroceryItem. Include private fields that hold an item's stock number, price, quantity in stock, and total value. Write a public function named dataEntry() that calls four private functions. Three of the private functions prompt the user for keyboard input for a value for one of the data fields stock number, price, and quantity in stock. The function that sets the stock number requires the user to enter a value between 1000 and 9999 inclusive; continue to prompt the user until a valid stock number is entered. The functions that set the price and quantity in stock require non-negative values; continue to prompt the user until valid values are entered. Include a fourth private function that calculates the GroceryItem's total value field (price times quantity in stock). Write a public function that displays a GroceryItem's values. Finally, write a main() function that declares a GroceryItem object, assigns values to its fields, and uses the display function.