What does void do in java?

You mean the tellItLikeItIs method? Yes, you have to specify void to specify that the method doesn't return anything. All methods have to have a return type specified, even if it's void.

It certainly doesn't return a string - look, there are no return statements anywhere. It's not really clear why you think it is returning a string. It's printing strings to the console, but that's not the same thing as returning one from the method.

The reason the code will not work without void is because the System.out.println(String string) method returns nothing and just prints the supplied arguments to the standard out terminal, which is the computer monitor in most cases. When a method returns "nothing" you have to specify that by putting the void keyword in its signature.

You can see the documentation of the System.out.println here:

http://download.oracle.com/javase/6/docs/api/java/io/PrintStream.html#println%28java.lang.String%29

To press the issue further, println is a classic example of a method which is performing computation as a "side effect."

When the return type is void, your method doesn't return anything.

Look again at your code: There's no return in that method. You print to the console and exit.