Step $1$: Allow a member to select multiple items before going to the checkout

a$)$ Introduce basket as a field in the Member class which will be used to store those items

selected by a member. It should be declared to be an ArrayList collection class object

and it should have a declaration similar to that of animalCollection in the Zoo class.

$.$ The field basket will eventually replace the item field but do not remove the item

field at this point as otherwise your code will not compile

b$)$ Modify the Member class's selectItem$()$ so that the item that is selected is added to

the basket.

c$)$ Add a toString$()$ method to the Item class which returns an item's details in a format

identical to the example below:

milk at $89$p

where milk is the name of the item and $89$ is the cost of that item.

See the Animal class for similar methods.

d$)$ Using a while loop with a counter, write a new method showBasket$()$ for the Member

class. It should print out the details of each item in the shopping basket using the item's

toString$()$ method.

Using a while loop with a counter write a new method calculateCostOfBasket$()$ which checks

the basket for each item and its price and calculates the total cost of all the items in the basket

before finally returning the cost as a whole number.

In the below you will amend the checkout$()$ method so that all the items in a member's

basket are processed

You should again re$-$compile after each of these parts.

Step$2$:

a$)$ Introduce a getBasket$()$ method in the Member class $--$ it will eventually replace the

getItem$()$ method. The method header should be

public ArrayList getBasket$()$

which means that this method returns an ArrayList object which contains Item objects.

Modify the checkout$()$ method in the Store class so that a call to the member's

getBasket$()$ method is made inside the method body. You will also need to create a

local variable to store whatever you are getting from the getBasket$()$ method call, name it

basket. Do not remove the original call to the getItem$()$ method at the moment or your

code will not compile but eventually it will be removed.

The checkout$()$ method will now need to process the items in the basket. For this you

will need a loop and a $$running total$$ to calculate the cost of the items stored in the basket

as you loop through. Each time round the loop you will "retrieve" an item from the basket

so use a for$-$each loop to do this.

if you haven't already done so$,$ make sure that the shopping basket of a member is emptied

after successfully buying the items. Look in the JDK documentation for the ArrayList

in order to find a suitable method which can be used to empty the ArrayList.

Finally remove the field item and the method getItem$()$ from the Member class. The

project should still compile and execute correctly $--$ if it does not then you need to re$-$

examine and modify your code.

Step $3$: Allow a member to "put back" items

a$)$ Write a method putItemBack$()$for the Member class which removes an item from the

shopping basket. It is passed an int parameter indicating the position in the list of the item

you wish to remove.

b$)$ Write a second method putItemBack$()$for the Member class that is passed a String

parameter indicating the name of the item to be removed. Note that this method has the

same name as the method in Part a$)$ but has a different signature $($so this is allowed$).$

c$)$ Write a method putExpensiveItemsBack$()$for the Member class which removes

items $($note the plural$)$ with a price greater than or equal to a specified amount. This latter

value is passed to the method as a parameter.

d$)$ Next add a field to the Store class called maxMumberOfItems that stores the maximum

number of items that a basket should hold. Then, write a method basketOverFull$(),$

also for the Store class, that is passed a basket object as the method argument $.$ This method should be called from

checkout$()$ and if the basket does contain more than the allowed limit

$($maxMumberOfItems$)$ then it returns true, otherwise it returns false. Depending on

this value, the member is allowed $($or not$)$ to pay for their items

Step $4$ with code enhancements:

a$)$ Write a method showMembers$()$ in the Store class that outputs details of all the members

registered to shop at a store

In order for this method to work correctly, you will need to add a new feature to the Store

class $($i$.$e and ArrayList of members $)$ and a new method in Member$($toString$()).$

One obvious enhancement is to change the output so that it produces the outputs using

pound signs e$.$g$.3\mathrm{.}04$ and $49$p$.$ To do this, you should first return to the

getPriceString$()$ method of the Item class and make sure that this method returns

the price of an item in the new format. Once you have done this, it is helpful to perform a

little reorganisation. Move the code that actually does the conversion into a second method

convertPenceToString$()$ that returns a String and call this new method from

getPriceString$()$