if there is no use of type compatibility between array types. Remember that in Java, for a reference variable of some type referring an object of its supertype is forbidden: arrows in Figure 8 ...

In a previous Java 101 tutorial, you learned how to better organize your code by declaring reference types (also known as classes and interfaces) as members of other reference types and blocks.

It's not very restrictive. However, rules are different from conventions. Java naming conventions for variables, methods and reference types are where things get a little more complicated. For example ...

The default constructor in Java takes no arguments -- it simply initializes reference types to null and primitive types to the binary equivalent of zero. That means instance variables are assigned as ...