HTW Berlin Fachbereich 4 Internationaler Studiengang Internationale Medieninformatik (Bachelor) Info 2: Informatik II Winter Term 2010/11

1. You all know what a calculator is! Here's some code: calculator-full-solution. Have a look at how it solves the problem of reading in a digit followed by an operator followed by a digit, and how to calculate the value when = is pressed.
2. Is there anything impoutant missing in this calculator? Beware: do not expect to read and understand this in the first few minutes of the lab! Read it at home, discuss it with others, perhaps over the class forum so that we can join in and help! How does it work?
3. What are hexadecimal numbers?

Lab exercises

1. Implement the missing functionality for single digit numbers and only one operator discovered in the pre-lab.
2. Extend your integer calculator to include buttons for entering in the hexadecimal digits. Make the calculator do its calculations and display in hexadecimal notation.
3. Integrate a checkbox for switching between decimal and hexadecimal formats. Do not show the hexadecimal digits (or grey them out) when you have the calculator in decimal mode.
4. What test cases do you need to test your calculator?

For the bored:

5. Make a whole collection of calculators: binary, octal, decimal, hexadecimal. Maybe make a CalculatorFactory that takes the base as a parameter to the constructor, figures out how to layout the buttons nicely, and calculates in the selected base mode?