We were too much in a hurry to enter the code, taking shortcuts and not being
careful about each step. This happens frequently when we are overconfident.
The first line with indexes[i] += indexes[swap]
is correct. However, the
second line is wrong. In our example, we wrote y = x - y
, but that is
not equivalent to y -= x
. Our code should have been
indexes[swap] = indexes[i] - indexes[swap]
.
We run the test and it passes this time. Fantastic! Keep the test green to keep the code clean. We have also improved our unit test to confirm that the numbers in the shuffled index are exactly the same as before.
We commit our changes to our local repository, describing our improvements, such as better tests, improved swapping algorithm and having set up NetBeans to automatically run our unit tests every time we run our game. We could submit our changes individually as separate commits or as one, but we should take care that every commit by itself does not break the build.
We hope you enjoyed this tutorial. If you did, you will also enjoy our courses. We suggest you start with Extreme Java - Advanced Java, followed by Extreme Java - Concurrency Performance for Java 8.
We deliver relevant courses, by top Java developers to produce more resourceful and efficient programmers within their organisations.
We can help make your Java application run faster and trouble-shoot concurrency and performance bugs...