Any basic software development tool has to necessarily allow you to verify if a program works correctly. This is the function of JUnit, a framework or set of classes for Java developers.
Detection of code execution errors
To make sure that the software development is running as expected JUnit analyzes the code execution, returning a correct result according to the data provided if there aren't any problems. The purpose is to find execution errors, which can be fundamental, especially in complex developments in which it is more complicated to locate them.
The ideal complement for development environments
JUnit works as a library from which instructions are read and executed, therefore it must be associated to development environments. Its use also allows us to control regression testing when part of the code is modified and we want to make sure that that modification doesn't change its functioning.
If you're a software developer or you're interested in becoming one, download JUnit and make sure your code has no errors.