Exercise 12-1. Create a class Invoice
, which has a string member vendor
and a double member amount
, as well as a method to output the two properties of the invoice. Overload the addition operator so that if the vendor
properties match, the amount
properties of the two invoices are added together in a new invoice. If the vendor
properties do not match, the new invoice is blank. Include some test code to test the addition operator.
Exercise 12-2. Modify the Invoice
class so that two invoices are considered equal if the vendor
and amount
properties match. Test your methods.
Exercise 12-3. Modify the Invoice
class once more so that you can determine whether one invoice is greater than or less than another. Test your methods.
Exercise 12-4. Create a class Foot
and a class Meter
. Each should have a single parameter that stores the length of the object, and a simple method to output that length. Create a casting operator for each class: one that converts a Foot
object to a Meter
object, and one that converts a Meter
object to a Foot
object. Test these operators to make sure they work.