This e-book will not cater to the Java programming language in detail. Having said that, it is assumed that the reader knows the Java programming fundamentals. For a refresher course on Core Java and programming fundamentals the reader is advised to refer to other texts or online content. A good place to start learning about the Java programming fundamentals is here

When we think about a Java class, we can immediately associate it with two things: attributes and methods. We have also used the existing classes String and Scanner extensively to write Java programs. These classes are a part of the Java Application Programming Interface (API).

One of the primary goals is to write code that can be reused in many applications. We can achieve this goal by encapsulation of the data elements together with the methods. We are not bothered about the implementation details.