Lesson: Classes
Every object is either a reference or primitive type. Reference types all
inherit from
java.lang.Object. Classes, enums, arrays, and interfaces are all reference types. There is a
fixed set of primitive types:
boolean,
byte,
short,
int,
long,
char,
float, and
double. Examples of reference types
include
java.lang.String, all of the wrapper classes for primitive types such as
java.lang.Double, the interface
java.io.Serializable, and the enum
javax.swing.SortOrder.
For every type of object, the Java virtual machine instantiates an
immutable instance of
java.lang.Class
which provides methods to examine the runtime properties of the object
including its members and type information.
Class
also provides the ability to create new classes and objects. Most importantly,
it is the entry point for all of the Reflection APIs. This lesson covers the
most commonly used reflection operations involving classes:
