title: Why use JUnit for testing?
body: <p>Maybe my question is a newbie one, but I can not really understand the circumstances under which I would use <a href="/questions/tagged/junit" class="post-tag" title="show questions tagged 'junit'" rel="tag">junit</a>?</p>
  
  <p>Whether I write simple applications or larger ones I test them with the <code>System.out</code> statements and it seams quite easy to me. </p>
  
  <p>Why create test-classes with JUnit, unnecessary folders in the project if we still have to call the same methods, check what they return and we then have an overhead of annotating everything? </p>
  
  <p>Why not write a class and test it at once with <code>System.out</code> but not create Test-classes?</p>
  
  <p>PS. I have never worked on large projects I am just learning. </p>
  
  <p>So what is the purpose?</p>