Game Development Reference
In-Depth Information
Note
It is possible to use, instead of the Java
import
keyword, the fully qualified
class name, that is, to preface the class name with the package name, right inside your
Java code. Convention dictates using the import statement; however, line 20 in
Figure
3-2
could be written as
javafx.scene.control.Button btn = new
javafx.scene.control.Button();
if you wanted to buck standard Java pro-
gramming convention.
Java Classes: Logical Java Constructs to
Build On
The next logical Java programming construct beneath the package level is the Java
class
level, as you saw in the import statement, which references both the package that
contains the class and a class itself. Just as a package organizes all the related classes,
so too a class organizes all its related methods, variables, and constants and, some-
times, other
nested
classes.
Thus, the Java class is used to organize your Java code at the next logical level of
functional organization, and so your class will contain Java code constructs that add
functionality to your application. These may include methods, variables, constants,
nested classes, or inner classes.
Java classes can also be used to create Java
objects
. Java objects are
constructed
,
using your Java class, and have the same name as the Java class and as that class's
con-
structor method
.
As you saw in
Figure 3-2
, you
declare
your class, using a Java
class
keyword,
along with a name for your class. You can also preface the declaration with Java
modi-
fier
keywords, which you will be studying later in this chapter (see the section “Java
Modifier Keywords: Access Control and More”). Java modifier keywords are always
placed
before
(or in front of) the Java class keyword, using the following format:
<modifier keywords>
class
<your custom classname goes
here>
One of the powerful features of Java classes is that they can be used to
modularize
your Java game code so that your core game application features can be a part of a
high-level class that can be
subclassed
to create more specialized versions of that
class. Once a class has been subclassed, it becomes a
superclass
, in Java class hier-
