|I think ijack's point is that you keep repeating the same mistakes, and these mistakes are caused by a misunderstanding of some very fundamental concepts. |
You're trying to write an essay in (let's go with) German without first learning the language. While we can answer your question, I suspect you'll either fail to grasp the reasoning behind the answer, or worse you'll grasp the wrong reason. It would not be your fault, but your potential to learn Java would be harmed just the same. I suggest taking a beginners programming class, read a beginners programming book, or at the very least find someone you can talk to face-to-face with before you try to tackle Java on your own. First you crawl, then you walk, then you run.
How To Ask Questions The Smart Way