using r language

8. Cash RegisterThis exercise assumes you have created the RetailItem class for Programming Exercise 5. Create a CashRegister class that can be used with the RetailItem class. The CashRegister class should be able to internally keep a list of RetailItem objects. The class should have the following methods: A method named purchase_item that accepts a RetailItem object as an argument. Each time the purchase_item method is called, the RetailItem object that is passed as an argument should be added to the list. A method named get_total that returns the total price of all the RetailItem objects stored in the CashRegister object’s internal list. A method named show_items that displays data about the RetailItem objects stored in the CashRegister object’s internal list. A method named clear that should clear the CashRegister object’s internal list. Demonstrate the CashRegister class in a program that allows the user to select several items for purchase. When the user is ready to check out, the…

5. RetailItem ClassWrite a class named RetailItem that holds data about an item in a retail store. The class should store the following data in attributes: item description, units in inventory, and price. Once you have written the class, write a program that creates three RetailItem objects and stores the following data in them: Description    Units in Inventory    PriceItem #1    Jacket    12    59.95Item #2    Designer Jeans    40    34.95Item #3    Shirt    20    24.95