Java in easy steps, 7th edition

Mike McGrath

• Publisher: In Easy Steps Limited
• Year: 2019
• ISBN:
  9781840788891
• Topic: Computer Science
• Subtopic: Programming in Java
• Index: Computer Science

Java in easy steps, 7th edition instructs you how to easily create your own Java programs. The book contains separate chapters on the major features of the Java language. Complete example programs with colourized code illustrate each important aspect of Java programming – all in easy steps.

This book assumes no previous knowledge of any programming language so it's ideal for the newcomer to computer programming. Each chapter builds your knowledge of Java. By the end of this book you will have gained a sound understanding of the Java language and be able to write your own Java programs and compile them into executable files that can be run on any Java-enabled device.

This 7th edition of Java in easy steps covers the many exciting features of Java, including:

• How to quickly run statements in the interactive shell named jshell - similar to the Python interpreter:
• How to make programs with the javac compiler and execute them with the java runtime.
• How to produce interactive Windows apps that can be easily distributed as jar program bundles.
• How to create mobile device apps using Java functionality within the Android operating system.

Table of Contents

• Getting started
• Performing operations
• Making statements
• Directing values
• Manipulating data
• Creating classes
• Importing functions
• Building interfaces
• Recognizing events
• Deploying programs

1

Getting started

Welcome to the exciting world of Java programming. This chapter shows how to create and execute simple Java programs, and demonstrates how to store data within programs.

Introduction

Installing the JDK

Writing a first Java program

Compiling & running programs

Creating a variable

Recognizing data types

Creating constants

Adding comments

Troubleshooting problems

Summary

Introduction

The Java™ programming language was first developed in 1990 by an engineer at Sun Microsystems named James Gosling. He was unhappy using the C++ programming language so he created a new language that he named “Oak”, after the oak tree that he could see from his office window.

This is “Duke” – the friendly mascot of the Java programming language.

As the popularity of the World Wide Web grew, Sun recognized that Gosling’s language could be developed for the internet. Consequently, Sun renamed the language “Java” (simply because that name sounded cool) and made it freely available in 1995. Developers around the world quickly adopted this exciting new language and, because of its modular design, were able to create new features that could be added to the core language. The most endearing additional features were retained in subsequent releases of Java as it developed into the comprehensive version of today.

The essence of Java is a library of files called “classes”, which each contain small pieces of ready-made proven code. Any of these classes can be incorporated into a new program, like bricks in a wall, so that only a relatively small amount of new code ever needs to be written to complete the program. This saves the programmer a vast amount of time, and largely explains the huge popularity of Java programming. Additionally, this modular arrangement makes it easier to identify any errors than in a single large program.

Java technology is both a programming language and a platform. In Java programming, the source code is first written as human-readable plain text files ending with the .java extension. These are compiled into machine-readable .class files by the javac compiler. The ja...