2. Importing packages doesn't recursively import sub-packages.
3. Sub-packages are really different packages, happen to live within an enclosing package. Classes in sub-packages cannot access classes in enclosing package with default access.
4. Comments can appear anywhere. Can't be nested. No matter what type of comments.
5. At most one public class definition per file. This class name should match the file name. If there are more than one public class definitions, compiler will accept the class with the file's name and give an error at the line where the other class is defined.
3. Sub-packages are really different packages, happen to live within an enclosing package. Classes in sub-packages cannot access classes in enclosing package with default access.
4. Comments can appear anywhere. Can't be nested. No matter what type of comments.
5. At most one public class definition per file. This class name should match the file name. If there are more than one public class definitions, compiler will accept the class with the file's name and give an error at the line where the other class is defined.
