Introduction

Testing allows you to make sure your Java code performs correctly. For example, if you were calculating employees' pay, you would want the code to be accurate; otherwise, your organization may face legal consequences. While not every programming issue leads to legal doom, it is still a good idea to test your code.

Writing tests while you code, as opposed to when you are done, can speed up your work. This is because you won't be spending time trying to figure out why things don't seem to work. Instead, you will know exactly what part of the code isn't correct. This is especially useful for any code that requires complex logic.

In addition to this, as new enhancements are added to the code, you will want to make sure that nothing in the new code breaks the old functionality. Having a suite of well-written unit tests can really help in this regard. If you are a new developer hired into a team that has been working on an application for some time...