Book Image

Learn Java with Projects

By : Dr. Seán Kennedy, Maaike van Putten
5 (3)
Book Image

Learn Java with Projects

5 (3)
By: Dr. Seán Kennedy, Maaike van Putten

Overview of this book

Learn Java with Projects stands out in the world of Java guides; while some books skim the surface and others get lost in too much detail, this one finds a nice middle ground. You’ll begin by exploring the fundamentals of Java, from its primitive data types through to loops and arrays. Next, you’ll move on to object-oriented programming (OOP), where you’ll get to grips with key topics such as classes, objects, encapsulation, inheritance, polymorphism, interfaces, and more. The chapters are designed in a way that focuses on topics that really matter in real-life work situations. No extra fluff here, so that you get more time to spend on the basics and form a solid foundation. As you make progress, you’ll learn advanced topics including generics, collections, lambda expressions, streams and concurrency. This book doesn't just talk about theory—it shows you how things work with little projects, which eventually add up to one big project that brings it all together. By the end of this Java book, you’ll have sound practical knowledge of Java and a helpful guide to walk you through the important parts of Java.
Table of Contents (22 chapters)
1
Part 1: Java Fundamentals
9
Part 2: Object-Oriented Programming
15
Part 3: Advanced Topics

Iterating over arrays

There are different methods to iterate over arrays. We will have a look at the use of the traditional for loop and the enhanced for loop (also known as the for-each loop).

Using the for loop

We can use the traditional for loop to iterate over an array by using an index variable. The loop starts at index 0 and continues until the index reaches the length of the array. Here’s an example that demonstrates how to use a for loop to iterate over an array and print its elements:

int[] results = {10, 20, 30, 40, 50};for (int i = 0; i < results.length; i++) {
    System.out.println("Element at " + i + ": " +
      results[i]);
}

The output will be as follows:

Element at 0: 10Element at 1: 20
Element at 2: 30
Element at 3: 40
Element at 4: 50

At this point, we know enough to revisit the example that we saw at the beginning of the chapter, calculating the average of several...