Reference Data Types and Variables

This chapter provides tutorial notes and example codes on reference data types and variables. Topics include 5 reference data types; reference data type variables store references to objects; multiple variables referring to a single object; superclass-subclass relation; superinterface-subinterface relation; interface-class relation; type casting.

Reference Types Supported in Java

Creating Class Type Objects

Class Type Variables Storing References

Interface Type Variables

Class and Interface Hierarchy

Supertype and Subtype

Explicit and Implicit Type Casting

Type Casting Example Program

Type Casting Compile and Runtime Error

Conclusion:

Table of Contents

 About This Book

 Installing JDK 1.8 on Windows

 Execution Process, Entry Point, Input and Output

 Primitive Data Types and Literals

 Bits, Bytes, Bitwise and Shift Operations

 Managing Bit Strings in Byte Arrays

Reference Data Types and Variables

 StringBuffer - The String Buffer Class

 System Properties and Runtime Object Methods

 Generic Classes and Parameterized Types

 Generic Methods and Type Inference

 Lambda Expressions and Method References

 Execution Threads and Multi-Threading Java Programs

 ThreadGroup Class and "system" ThreadGroup Tree

 Synchronization Technique and Synchronized Code Blocks

 Deadlock Condition Example Programs

 Garbage Collection and the gc() Method

 Outdated Tutorials

 References

 PDF Printing Version