FHTW Berlin Fachbereich 4 Internationale Medieninformatik PROG2: Programmierung II Sommersemester 2003

Solutions to Exercise 4 - Calculator

Part of my secret learning objectives program was hidden in this exercise: make the students understand why documentation is important and not just busy work. Another objective was to show you that you can link together a lot of object oriented classes to make something even better than you had before!

• Volker and Jeanette had a nasty encounter with null pointer exception - they found a really grotty problem where by extending a class you manage to break it! Have a look at the report, this is a problem sometimes encountered that makes you want to tear your hair out!
• Katja and Lars enhanced their calculator with Swedish colors and made it a TextArea instead of a TextField. And since they were bored, they went ahead and implemented parentheses, exponentiation, and even started on multi-digit numbers.
• Susanne and Stefan thought it would be easy to make their own GUI... now they think differently! While they were at it, they added conversion to binary and hexadecimal.
• Kaspar and Matthias changed the look and feel to make it more of an Apple-Calculator than a boring Windows one.
• Alexander and Tomasz discover the StringTokenizer for easy reading of the bits from the input string.
• Mariam and Jana - Markus and Daniel - Tilman and Andreas - Frank and Andreas - Doris and Ralf - Nishan and Susanne and Birol - Gregor and Jenny - Denis and Sandy - Ulrike and Andrea - Farhia and Patricia - Mandy and Annika - Denise and Raphael - Kristin and Frank - Jana and Steffi - Olga and Sebastian -Hans - Jorgen - Bettina and Claudia -

No exercise from:

• Xandra and Ericco - Saima ?