What is JUnit and how do you use it?
JUnit is a unit testing framework developed as part of the Java programming language. It allows developers to write tests to validate their code, and has become the standard in testing frameworks for Java. JUnit has been widely used across many languages and platforms, and is now widely accepted as the de facto standard for unit testing in those languages.
JUnit allows for writing tests for other classes that are separate from your main code base through its annotations. In this way, you can write test cases that aren’t actually part of your original project—when you want to test something in another class, whether it’s your own or someone else’s code.