Learning the Java Language
This trail covers the fundamentals of programming in the Java programming language.
Object-Oriented Programming Concepts
What is an object?
What is a class?
WHat is inheritance?
What is an interface?
What is a package?
Language Basics
Variables
Primitive Data Types
Arrays
Summary of variables
Operators
Assignment, Arithmetic, and Unary Operators
Equality, Relational, and Conditional Operators
Bitwise and Bit Shift Operators
Summary of Operators
Expressions, Statements, and Blocks
Control FLow Statements
The if-then and it-then-else Statements
The switch Statement
The while and do-while Statements
The for Statement
Branching Statements
Summary of Control Flow Statements
Classes and Objects
Classes
Declaring Classes
Declaring Member Variables
Defining Methods
Providing Constructors for Classes
Passing Information to a Method or a Constructor
Objects
Creating Objects
Using Objects
More on Classes
Returning a Value from a Method
Using the this Keyword
Controlling Access to a Member of a CLass
Understanding Class Members
Initializing Fields
Summary of Creating and Using Classes and Objects
Nested Classes
Inner Class Example
Local Classes
Anonymous Classes
Lambda Expressions
Method Reference
When to Use Nested Classes, Local Classes, Anonymous Classes, and Lambda Expressions
Enum Types
Annotations
Annotation Basics
Declaring an Annotation Type
Predefined Annotation Types
Type Annotations and Pluggable Type Systems
Repeating Annotations
Interfaces and Inheritance
Interfaces
Defining an Interface
Implementing an Interface
Using an Interface as a Type
Evolving Interfaces
Default Methods
Summary of Interfaces
Inheritance
Multiple Inheritance of State, Implementation, and Type
Overriding and Hiding Methods
Polymorphism
Hiding Fields
Using the Keyword super
Object as a Superclass
Writing Final Classes and Methods
Abstract Method and Classes
Summary of Inheritance
Numbers and Strings
Numbers
The Numbers Classes
Formatting Numeric Print Output
Beyond Basic Arithmetic
Summry of Numbers
Characters
Strings
Converting Between Numbers and Strings
Manipulating Characters in a String
Comparing Strings and Portions of Strings
The StringBuilder Class
Summary of Characters and Strings
Autoboxing and Unboxing
Generics
Why use Generics?
Generic Types
Raw Types
Generic Methods
Bounded Type Parameters
Generic Methods and Bounded Type Parameters
Generics, Inheritance, and Subtypes
Type Inference
Wildcards
Upper Bounded Wildcards
Unbounded Wildcards
Lower Bounded Wildcards
Wildcards and Subtyping
Wildcard Capture amd Helper Methods
Guidelines for Wildcard Use
Type Erasure
Erasure of Generic Types
Erasure of Generic Methods
Effects of Type Erasure and Bridge Methods
Non-Reifiable Types
Restrictions on Generics
Packages
Creating and Using Packages
Create a Package
Naming a Package
Using Package Members
Managing Source and Class Files
Summary of Creating and Using Packages
Last modified: 10 March 2024