Book Image

Java Fundamentals

By : Gazihan Alankus, Rogério Theodoro de Brito, Basheer Ahamed Fazal, Vinicius Isola, Miles Obare
Book Image

Java Fundamentals

By: Gazihan Alankus, Rogério Theodoro de Brito, Basheer Ahamed Fazal, Vinicius Isola, Miles Obare

Overview of this book

Since its inception, Java has stormed the programming world. Its features and functionalities provide developers with the tools needed to write robust cross-platform applications. Java Fundamentals introduces you to these tools and functionalities that will enable you to create Java programs. The book begins with an introduction to the language, its philosophy, and evolution over time, until the latest release. You'll learn how the javac/java tools work and what Java packages are - the way a Java program is usually organized. Once you are comfortable with this, you'll be introduced to advanced concepts of the language, such as control flow keywords. You'll explore object-oriented programming and the part it plays in making Java what it is. In the concluding chapters, you'll get to grips with classes, typecasting, and interfaces, and understand the use of data structures, arrays, strings, handling exceptions, and creating generics. By the end of this book, you will have learned to write programs, automate tasks, and follow advanced courses on algorithms and data structures or explore more advanced Java courses.
Table of Contents (12 chapters)
Java Fundamentals
Preface

References


As you work with objects, it is important that you understand references. A reference is an address that indicates where an object's variables and methods are stored.

When we assign objects to variables or pass them to methods as parameters, we aren't actually passing the object itself or its copy – we are passing references to the objects themselves in memory.

To better understand how references work, let's illustrate this with an example.

Following is an example:

Create a new class called Rectangle, as follows:

public class Rectangle {

    int width;
    int height;

    public Rectangle(int width, int height){
        this.width = width;
        this.height = height;
    }

    public static void main(String[] args){
        Rectangle r1, r2;

        r1 = new Rectangle(100, 200);
        r2 = r1;

        r1.height = 300;
        r1.width = 400;
        System.out.println("r1: width= " + r1.width + ", height= " + r1.height);
        System.out.println("r2: width= " + r2.width...