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The Java Workshop
The Java Workshop

The Java Workshop: Learn object-oriented programming and kickstart your career in software development

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Profile Icon David Cuartielles Profile Icon Foster-Johnson Profile Icon Andreas Göransson
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€32.99
Full star icon Full star icon Full star icon Half star icon Empty star icon 3.1 (8 Ratings)
Paperback Oct 2019 606 pages 1st Edition
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€26.99
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€32.99
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Arrow left icon
Profile Icon David Cuartielles Profile Icon Foster-Johnson Profile Icon Andreas Göransson
Arrow right icon
€32.99
Full star icon Full star icon Full star icon Half star icon Empty star icon 3.1 (8 Ratings)
Paperback Oct 2019 606 pages 1st Edition
eBook
€26.99
Paperback
€32.99
Subscription
Free Trial
Renews at €18.99p/m
eBook
€26.99
Paperback
€32.99
Subscription
Free Trial
Renews at €18.99p/m

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The Java Workshop

2. Learning the Basics

Overview

In this chapter, we will be executing programs that do not have the typical linear flow that we have seen so far. You will first learn to use if, else, else if, and switch-case statements to control the flow of your programs. You will practice running for, while, and do-while loops in order to perform repetitive tasks in Java, and how to pass command-line arguments to modify how programs run. By the end of this chapter, you will be able to implement immutable, static (global) variables, alongside Java's variable type inference mechanism.

Introduction

Business applications have lots of special-case conditions. Such conditions may include finding changes in allocation rules starting at a particular year, or handling different types of employees differently based on their designation. To code for such special cases, you will require conditional logic. You basically tell the computer to perform a set of actions when a particular condition is met.

Before we delve into advanced Java topics, you need to know the basics of Java syntax. While some of this material might seem simple, you'll find you need to use the techniques and syntax shown in this chapter repeatedly in your applications.

As you've seen in Chapter 1, Getting Started, Java's syntax borrows heavily from C and C++. That's true for conditional statements that control the flow of your programs as well. Java, like most computer languages, allows you to do this. This chapter covers the basic syntax of the Java language, especially ways in...

Controlling the Flow of Your Programs

Imagine paying a bill from your e-wallet. You will only be able to make the payment if the credit balance in your e-wallet is greater than or equal to the bill amount. The following flowchart shows a simple logic that can be implemented:

Figure 2.1: A representative flow chart for an if-else statement

Here, the credit amount dictates the course of action of the program. To facilitate such scenarios, Java uses the if statement.

With the if statement, your application will execute a block of code if (and only if) a particular condition is true. In the following code, if the happy variable is true, then the block of code immediately following the if statement will execute. If the happy variable is not true, then the block of code immediately following the if statement will not execute.

boolean happy = true;// initialize a Boolean variable as true
if (happy) //Checks if happy is true
    System.out...

Looping and Performing Repetitive Tasks

In this chapter, we cover using loops to perform repetitive tasks. The main types of loop are as follows:

  • for loops
  • while loops
  • do-while loops

for loops repeat a block a set number of times. Use a for loop when you are sure how many iterations you want. A newer form of the for loop iterates over each item in a collection.

while loops execute a block while a given condition is true. When the condition becomes false, the while loop stops. Similarly, do-while loops execute a block and then check a condition. If true, the do-while loop runs the next iteration.

Use while loops if you are unsure how many iterations are required. For example, when searching through data to find a particular element, you normally want to stop when you find it.

Use a do-while loop if you always want to execute the block and only then check if another iteration is needed.

Looping with the for Loop

A for loop executes the same block...

Handling Command-Line Arguments

Command-line arguments are parameters passed to the main() method of your Java program. In each example so far, you've seen that the main() method takes in an array of String values. These are the command-line arguments to the program.

Command-line arguments prove their usefulness by giving you one way of providing inputs to your program. These inputs are part of the command line launching the program, when run from a Terminal shell window.

Exercise 15: Testing Command-Line Arguments

This exercise shows how to pass command-line arguments to a Java program, and also shows how to access those arguments from within your programs:

  1. Using the techniques from the previous exercises, create a new class named Exercise15.
  2. Enter the following code:
    public class Exercise15 {
        public static void main(String[] args) {
            for (int i = 0; i < args.length; i++) {
      ...

Summary

This chapter covered a lot of Java syntax—things you need to learn to be able to tackle the more advanced topics. You'll find yourself using these techniques in just about every Java application you write.

We started out by controlling the flow of the program using conditional statements such as if, else if, else, and switch statements. We then moved on to the different loops that can be used to perform repetitive tasks. After this, we looked at how to provide values during runtime using command-line arguments. This is one way to pass inputs to your Java applications. Every example in this chapter created a class, but we have not yet done much with these classes.

In the next chapter, you'll learn about classes, methods, and object-oriented programming, and how you can do a lot more with classes.

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Key benefits

  • Build a solid foundation in Java and focus on developing real-world applications
  • Implement the fundamental concepts of object-oriented programming in your code
  • Work with external data storage systems and learn how to efficiently handle data

Description

Java is a versatile, popular programming language used across a wide range of industries. Learning how to write effective Java code can take your career to the next level, and The Java Workshop will help you do just that. This book is designed to take the pain out of Java coding and teach you everything you need to know to be productive in building real-world software. The Workshop starts by showing you how to use classes, methods, and the built-in Collections API to manipulate data structures effortlessly. You’ll dive right into learning about object-oriented programming by creating classes and interfaces and making use of inheritance and polymorphism. After learning how to handle exceptions, you’ll study the modules, packages, and libraries that help you organize your code. As you progress, you’ll discover how to connect to external databases and web servers, work with regular expressions, and write unit tests to validate your code. You’ll also be introduced to functional programming and see how to implement it using lambda functions. By the end of this Workshop, you’ll be well-versed with key Java concepts and have the knowledge and confidence to tackle your own ambitious projects with Java.

Who is this book for?

This Java coding book is designed for anyone who is new to Java. Whether you’re an aspiring software developer, or are just curious about learning to code, then this book will get you on the right track. No prior programming experience is required.

What you will learn

  • Write clean, well-commented Java code that's easy to maintain
  • Debug logical errors and handle exceptions in your Java programs
  • Implement object-oriented and functional programming paradigms
  • Use regular expressions to search for information in text data
  • Work with information stored in databases using JDBC
  • Make HTTP requests from Java applications and parse the response data
  • Secure your data with cryptography and encryption
  • Write unit tests to validate your code with JUnit
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Publication date, Length, Edition, Language, ISBN-13
Publication date : Oct 31, 2019
Length: 606 pages
Edition : 1st
Language : English
ISBN-13 : 9781838986698
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Estimated delivery fee Deliver to Norway

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(Includes tracking information)

Product Details

Publication date : Oct 31, 2019
Length: 606 pages
Edition : 1st
Language : English
ISBN-13 : 9781838986698
Category :
Languages :
Tools :

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Table of Contents

18 Chapters
1. Getting Started Chevron down icon Chevron up icon
2. Learning the Basics Chevron down icon Chevron up icon
3. Object-Oriented Programming Chevron down icon Chevron up icon
4. Collections, Lists and Java's Built-In APIs Chevron down icon Chevron up icon
5. Exceptions Chevron down icon Chevron up icon
6. Libraries, Packages, and Modules Chevron down icon Chevron up icon
7. Databases and JDBC Chevron down icon Chevron up icon
8. Sockets, Files, and Streams Chevron down icon Chevron up icon
9. Working with HTTP Chevron down icon Chevron up icon
10. Encryption Chevron down icon Chevron up icon
11. Processes Chevron down icon Chevron up icon
12. Regular Expressions Chevron down icon Chevron up icon
13. Functional Programming with Lambda Expressions Chevron down icon Chevron up icon
14. Recursion Chevron down icon Chevron up icon
15. Processing Data with Streams Chevron down icon Chevron up icon
16. Predicates and Other Functional Interfaces Chevron down icon Chevron up icon
17. Reactive Programming with Java Flow Chevron down icon Chevron up icon
18. Unit Testing Chevron down icon Chevron up icon

Customer reviews

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Full star icon Full star icon Full star icon Half star icon Empty star icon 3.1
(8 Ratings)
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4 star 12.5%
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2 star 25%
1 star 0%
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SRIPATHY Jun 01, 2020
Full star icon Full star icon Full star icon Full star icon Full star icon 5
HANDS ON APPROACH. NICE BOOK FOR BEGINNERS. FAST SHIPPING & DELIVERY.
Amazon Verified review Amazon
Kate Feb 21, 2021
Full star icon Full star icon Full star icon Full star icon Empty star icon 4
Purchased for my high schooler who has a keen interest in programming and computer science. He has just devoured this book, and his programming teacher was impressed with it as well!
Amazon Verified review Amazon
Sutharsan Jun 01, 2024
Full star icon Full star icon Full star icon Empty star icon Empty star icon 3
At the time I am reading this book, the version of IntelliJ IDEA is 2024.1.2. While I understand that this is how things work in the world of computing, an advanced notice that the version in the book would be 2018.3.4 would have helped me, the reader, decide on the correct version to download and install. The two versions are vastly different. In exercise 1, step 4 does not tally with the image shown. If we name the project chapter01, where does ch01 come from? These are some issues I am seeing right at the beginning. I hope it would get better.
Subscriber review Packt
Xi Xiao Oct 19, 2021
Full star icon Full star icon Full star icon Empty star icon Empty star icon 3
I quickly went through the book today and here are my two cents. I think it's not a complete guide for beginners but is good for beginners as a practice book. The content covers some key fundamental parts of Java Programming and has some hands-on practice in each chapter on each topic. But it might be a bit hard to follow and fully understand the topic based only on the descriptions and instructions in the book. It's better for the learners to learn these topics somewhere else, with a teacher, or watch some online videos first to have some basic understandings of the topics first. Then use this book as a practice book to test and to get some deeper understandings.
Amazon Verified review Amazon
Robert Aug 17, 2021
Full star icon Full star icon Full star icon Empty star icon Empty star icon 3
The code you need to enter from this book is written in a strange font which makes it very hard to read. It's also difficult to find a way to access the online materials
Amazon Verified review Amazon
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