Abstract

In this section, we'll take a quick look at an important idea that relates to inheritance in Java. To wrap our heads around what we're going to talk about, I think it's best if we start an existing project in the system. So let's take a look at the code we have in the code files.

So far, we've done the following:

• The main method of our program creates a list of objects. These objects are either of the type Book or Poem, but we've placed them in a list of Literature objects, leading us to believe that the Book and Poem classes must inherit from or extend the Literature class.
• Once we've built this array, we simply iterate through it using a for loop and call the Print method of this for loop on each object.
• At this point, we're dealing with objects as Literature objects, not the Books or Poems that they are at the lowest level. This leads us to believe that the Literature class itself must implement a Print method; if we jump into the class, we'll see that this is true indeed.

However...