For Exercises 15 through 19, use the incremental development methodology to implement th...

For Exercises 15 through 19, use the incremental development methodology to implement the program. For each exercise, identify the program tasks, create a design document with class descriptions, and draw the program diagram. Map out the development steps at the start. Present any design alternatives and justify your selection. Be sure to perform adequate testing at the end of each development step.

Write a currency converter application. Allow the user to specify the from and to currencies and the amount to exchange. Use the interface of your choice to input these three values. When the application starts, read the exchange rates from a text file rate.txt. Use a text editor to create this text file. By using a text file, you can easily update the exchange rates. The format for the text file is

<name of currency> <units per dollar>

For example, the following shows how much $1 is worth in five foreign currencies:

French franc 5.95

Indonesian rupiah 12900.0

Japanese yen 123.91

Mexican peso 9.18

Papua New Guinea kina 2.381

You can get the exchange rates from various websites, one of which is http://www.oanda.com.