This Book s Conventions

< Day Day Up >

This Book's Conventions

The following conventions are used in this book:

Code lines, commands, statements, and any other code- related terms appear in a monospace typeface.
Placeholders that stand for what you should actually type appear in italic monospace . Text that you should type appears in bold monospace .
Throughout the book, there are special sidebar elements, such as:

Note

A note presents interesting information related to the discussion ”a little more insight or a pointer to some new technique.

Tip

A tip offers advice or shows you an easier way of doing something.

Caution

A caution alerts you to a possible problem and gives you advice on how to avoid it.

< Day Day Up >

Source Code Used in this Book

You can download all the source code and examples discussed within this book from http://www.samspublishing.com. Simply type this book's ISBN (0672326116) into the "search" window, press Enter, and you'll be taken to a page with links to the source code.

< Day Day Up >

Chapter 1. Introduction to Object-Oriented Concepts

Although it might be quite surprising, object-oriented (OO) software development has been around since the early 1960s. Although objects have become much more prevalent in today's software industry, many software shops have yet to venture into the OO arena. It is no secret that the software industry can be slow-moving at times. It is also true that, when working systems are in place, there has to be a compelling reason to replace them. This has hindered the propagation of OO systems. There are a lot of non-OO legacy systems (that is, older systems that are already in place) that seem to be working just fine ”so why risk potential disaster by changing them? In most cases you should not change them, at least not simply for the sake of change. There is nothing inherently wrong with systems written in non “OO code. However, brand-new development definitely warrants the consideration of using OO technologies.

Although there has been a steady and significant growth in OO development in the past 10 years , an entirely new venue has helped catapult it further into the mainstream. The emergence of the Web has opened a brand-new arena, where much of the software development is new and mostly unencumbered by legacy concerns. Even when there are legacy concerns, there is a trend to wrap the legacy systems in object wrappers.

Object Wrappers

Object wrappers are object-oriented code that includes structured code inside. For example, you can take a structured module and wrap it inside an object to make it look like an object.

Objects are slowly but surely making their way into our professional information systems (IS) lives ”and they cannot be ignored. With the success of Java and the introduction of Microsoft's .NET technologies, objects are becoming a major part of the IS equation. With the explosion of the Internet, now many years in the making, the electronic highway is really becoming an object-based highway . And as businesses gravitate toward the Web, they are gravitating toward objects, because the technologies used for the Web are mostly OO in nature.

This chapter is an overview of the fundamental OO concepts. The topics covered touch on most, if not all, of the topics covered in subsequent chapters, which explore the issues in much greater detail.

< Day Day Up >