Lecture 12 -Reading, Fixing and Updating

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Download the resource file above. The zip file contains 2 projects both of which have some bugs. Read the codes and fix the bugs.

Exercise 12.1

1. In the project 'HanoiTower', two methods are deleted by accident. One of them was written again. Another is not rewritten yet. Write it.

2. Drawing grid does not work properly. Find out the problem and fix it.

3. When the user moves the numbers, wrong numbers are displayed. At some point the application crashes. Find the bug and fix it.

4. Update the code to display the numbers vertically.

Exercise 12.2

1. We want to update the project 'Pattern'.

2. The original code works with a fixed length of password. Suppose that we keep the password as a string which consists of numbers from '0' to '8', like '53821'. The number of chracters is not fixed. Think about how to keep a variable length of password and how to realize it.

3. Do you think you can update the application keeping the most parts of the original codes? Or do you think it might be better you change the structure of the project?

4. Update the application to work with a variable length of password. (Don't make the process of receiving password, just use static final data.)