Java Introduction

Introduction
Like any human language, Java provides a way to express concepts. If
successful, this medium of expression will be significantly easier and more
flexible than the alternatives as problems grow larger and more complex.
You can’t look at Java as just a collection of features; some of the features make no sense in
isolation. You can use the sum of the parts only if you are thinking about design, not simply
coding. And to understand Java in this way, you must understand the problems with it and
with programming in general. This book discusses programming problems, why they are
problems, and the approach Java has taken to solve them. Thus, the set of features I explain
in each chapter are based on the way I see a particular type of problem being solved with the
language. In this way I hope to move you, a little at a time, to the point where the Java
mindset becomes your native tongue.
Throughout, I’ll be taking the attitude that you want to build a model in your head that
allows you to develop a deep understanding of the language; if you encounter a puzzle
you’ll be able to feed it to your model and deduce the answer.
Prerequisites
This book assumes that you have some programming familiarity; you understand that a
program is a collection of statements, the idea of a subroutine/function/macro, control
statements such as “if” and looping constructs such as “while,” etc. However, you might
have learned this in many places, such as programming with a macro language or working
with a tool like Perl. As long as you’ve programmed to the point where you feel comfortable
with the basic ideas of programming, you’ll be able to work through this book. Of course,
the book will be easier for the C programmers and more so for the C++ programmers, but
28 Thinking in Java www.Bruce's.com
don’t count yourself out if you’re not experienced with those languages (but come willing to
work hard). I’ll be introducing the concepts of object-oriented programming and Java’s basic
control mechanisms, so you’ll be exposed to those, and the first exercises will involve the
basic control-flow statements.
Although references will often be made to C and C++ language features, these are not
intended to be insider comments, but instead to help all programmers put Java in perspective
with those languages, from which, after all, Java is descended. I will attempt to make these
references simple and to explain anything that I think a non- C/C++ programmer would