Fundamental classes of the java.lang package

Since the classes in the java.lang package are considered fundamental to the JVM platform, many classes of this package will be mentioned regularly in the chapters that follow. This section is not meant to replace the Java API docs but to give some insight and background information. The classes that will be discussed here are:

• The Object class (java.lang.Object)
• The String class (java.lang.String)
• Primitive wrapper classes (Integer, Long, Short, Char, Float, and Double from java.lang)
• Exceptions and errors (java.lang.Exception and java.lang.)

Here's a class hierarchy diagram of the classes that are discussed here:

We will look at a lot more classes of the library during the course of this book.