Let's assume that your classes are working, and you have created an "A" object, and added 4 boxes. (5 x 5, 4 x 10, 2 x 4, and 6 x 12). Now choose the method for displaying all the box sizes. The following text might be displayed:

box: 5 x 5, cost $2.5

box: 4 x 10, cost $4.0

box: 2 x 4, cost $.8

box: 6 x 12, cost $7.2

Now choose the "A" method which sells a box. The method needs two pieces of information: height and width. If the height is 3 and the width is 6, then the following text should be displayed:

box: 4 x 10, cost $4.0

I need help with the second part, i can't seem to be able to come up with a loop that would work for that. A and B refers to two different classes, the postoffice class and a boxes class.