This comprehensive book equips readers with the skills necessary to develop computer applications in any language by helping them develop a framework for creating programs. The program development cycle and fundamental programming concepts are emphasized. Comes with free software: Microsoft Visual Basic 6.0, Working Model. To highlight emphasis on programming concepts instead of GUI elements, a limited number of program controls are used in the examples. For anyone interested in learning to program in Visual Basic.
PREFACE
To the Student
Welcome to the exciting and challenging world of programming! With new software development environments such as Visual Basic, you can create attractive, sophisticated Windows programs in a short time. Remember, however, that the look of the program is only a small part of the total package. For the program to be useful, it must do something. That is the point of programming—developing the logic for the program to make it do something useful. Because Visual Basic is event driven, it is also important to think about when something should happen, such as when the user clicks a button or types a value. This book teaches you basic programming concepts that include problem analysis, interface development, logic organization and design, and program development and testing. Learning the entire thought process behind writing programs will equip you with a solid foundation in programming. This foundation will prepare you to learn other computer languages or more advanced features of Visual Basic on your own.
To the Teacher
Computers continue to make amazing progress in speed and capabilities. Ideally, we as teachers want our students to use state-of-the-art software as they learn fundamental programming concepts. Visual Basic is a popular application development tool with useful features for designing professional-looking screens and coding and testing programs. With this tool, the programmer has easy access to all the buttons, boxes, pictures, and menus that you commonly see in shrink-wrapped software today. Although it is fun to try using each of these objects in a program, the students can learn much of this on their own after understanding basic concepts about adding an object to a form, setting its properties, and using its methods and events in code. The continuing challenge is to develop logical thinking skills to be able to translate a problem description into appropriate logic structures and coding statements. The event-driven nature of Visual Basic further requires that students learn how to organize their code into appropriate events related to GUI objects.
Introduction to Computer Programming with Visual Basic 6: A Problem-Solving Approach will furnish students with a problem-solving framework for developing event-driven programs. Through repeated illustrations of this framework in end-of-chapter case studies, students can see how to identify the major input, processing, and output needs of a program. From this list, they learn how to sketch an interface that serves all the needs identified during problem analysis. Next, they develop and document the macro-level logic by using an Object-Event Diagram (OED). The OED is a transitional tool that shows students how to use the interface they just designed to begin organizing their program into events that relate to specific objects. After the events have been identified, traditional program development tools are used to depict design logic, develop adequate test plans, translate logic designs into Visual Basic code, test and debug as necessary, and finalize the documentation of the package.
To further emphasize our focus on problem solving, chapter discussions and case studies use just three Visual Basic controls: text boxes, labels, and command buttons. For instructors who want to present additional controls, we include a comprehensive list of User Interface Objects in Appendix A. Having this information in a separate section gives the instructor total control of the amount and sequence of GUI coverage for a particular course. Related objects are grouped together in this section, and short examples are provided to illustrate their application. End-of-chapter problems also provide opportunities for instructors to cover additional controls, as needed or desired.
Approach
When event-driven tools such as Visual Basic were first introduced in the classroom, classroom coverage of the new GUI features made application development fun and exciting. Unfortunately, too much focus on GUI topics took important time away from teaching fundamental programming concepts. Students could develop intricate interfaces, but had difficulty organizing and developing the code underneath the GUI to make it do something. Our teaching philosophy for an introductory programming course is to equip students with the essential skills needed to develop computer applications using any language. This philosophy requires that students gain a framework for creating programs, not just memorize the syntax rules of a particular language.
Introduction to Computer Programming with Visual Basic 6 A Problem-Solving Approach was written in response to the need for a textbook that focuses on teaching programming. To accomplish this objective, we identified three goals for this book. First, we want to teach a disciplined process for developing a computer program that includes logic design before the coding step and sufficient testing after. Second, we want to teach universal programming concepts so that our students have the tools to transition to other programming languages. Third, we want the students to follow standards as they write their code, including naming and indentation conventions.
The disciplined process we recommend is introduced early in Chapter I and reinforced with a complete case study at the end of each chapter. To help students understand the relationship of GUI objects and their events, we developed a tool called the Object-Event Diagram (OED). As students transition from interface design to logic development, the OED helps them organize major processing steps using the event-driven paradigm. Because each event procedure is like a mini-program, there is still a need for logic design in the individual event procedures. Hence, both flowcharts and pseudocode are used in most of the chapters to illustrate major logic structures. Teachers can choose the one they like better. Pseudocode is easier to type and takes less space, but for the majority of students who tend to learn visually, seeing a graphical design tool increases their understanding.
To achieve the goal of teaching universal programming concepts, this book concentrates on the various logic structures and types of programming statements used in most programming languages, instead of teaching all the "bells and whistles" of Visual Basic. In chapter discussions and the majority of case studies, we have purposely elected to design GUIs that generally use only three controls: labels, text boxes, and command buttons. This does not mean, however, that the students must be limited to these controls. The fundamental concepts of properties, methods, and events apply to all GUI objects, so students should be able to transfer their understanding of these concepts when using "new" controls. In fact, the students should be encouraged to demonstrate their understanding of the general nature of screen objects by incorporating a new control in several programming exercises. Several exercises suggest modifying the chapter examples to incorporate new controls, or writing a new program to try a different control. Using Appendix A, "Visual Basic User Interface Objects," as a handy reference, the instructor has the added flexibility to use different controls in different semesters, or to introduce them in a different order.
Our final goal was the most challenging to achieve because each of us practiced slightly different standards. Our situation is not unlike what students will experience when they begin each new job. Students need to recognize that different languages and/or different companies are likely to have their own standards conventions. Therefore, to function effectively within the organization or with the new tool, they must learn the convention and then use it consistently to allow others to quickly read and understand the code. In selecting our standards for the text, we spent considerable time debating the advantages and disadvantages of each. In each case, our final decision was based on the pedagogical value of the specific standard in teaching a programming course.
We follow the widely accepted prefix notation standards for naming GUI objects, for example, but opted for a somewhat unique scope prefix. When using Visual Basic, students may notice that the word module has multiple definitions, depending on context. Traditional programming had yet another meaning for module to refer to blocks of code such as procedures and functions. Rather than add to the students' confusion by using the "m" prefix for "module" scope, we use the "f" prefix for "form" or "file" scope. This standard helps students remember that the placement of the declaration helps determine the variable's scope. Additionally, because one of our conventions is to explicitly declare the types of all variables, we elected not to include type prefixes on variable names. Because it is just as easy to press Shift+F2 on a variable to quickly look up its type, we thought that there was no added benefit to requiring type prefixes.
Assumptions About the Student
Introduction to Computer Programming with Visual Basic 6: A Problem-Solving Approach is aimed primarily at the undergraduate introductory programming course. Because this course is typically offered in the freshman or sophomore year, this book could be used by a variety of two- or four-year institutions. Students from a wide variety of disciplines, both computingrelated and not, could benefit from a programming course like this to gain essential programming skills and improve their logical thinking.
Visual Basic is a Windows application with the typical File, Edit, and Help menus. Programmers must use the computer as a tool to type and edit their programs, which are then saved in files. Hence, this book assumes that readers have some basic computer literacy as well as mouse and keyboarding skills. It is helpful to have experience using at least one common Windows application such as a word processor or a spreadsheet, where you have used typical editing (cut, copy, and paste) and file manipulation (opening, saving) features. Additionally, because each Visual Basic program consists of multiple files, it is important to know how to create folders and how to copy, move, rename, or delete files.
Only basic math and algebra skills are assumed for this book, such as calculating a percentage, taking a percentage of another number (for example, sales tax), or converting units (for example, centimeters to inches). When more difficult math is required, the equation is provided. This means that students should be able to read an algebraic equation and recognize the mathematical operations required (multiplication, division, exponentiation, and so on) and their correct order of operations.
Key Features
The content and features of this book were designed to support our goal of teaching students how to program using any language. They are also a result of extensive class testing by all the authors.
Back to the Basics: Programming Fundamentals
This book concentrates on presenting a disciplined program development process, using fundamental logic control structures and teaching the concepts and statements of a programming language. Chapter 1, "Introductory Programming Concepts and the Visual Basic Environment," lays the foundation for the beginning programmer by introducing the six steps of program development. The remaining chapters follow through with illustrative case studies. Using a limited number of Visual Basic controls throughout the text gives the instructor more time to teach programming fundamentals and makes it possible for the student to concentrate on learning these fundamentals.
Case Studies
End-of-chapter case studies are used to illustrate and continually reinforce the six steps of the program development process. In each case study, a programming problem is presented and solved by following the steps from problem analysis through interface and logic design, coding, and testing. Complete documentation of the process is included in the case study section of each chapter. These examples also provide the instructor with complete problems that can be used for illustration purposes in lecture, developed together during lab, or studied by the students at home. Often at the end of the chapter, programming exercises ask the students to make modifications to the case study problem.
Appendix of Visual Basic User Interface Objects
Students learn the basic concepts of setting properties for GUI objects and putting code in an event procedure early in the book. Appendix A, "Visual Basic User Interface Objects," serves as a handy reference that groups related objects together and describes their primary uses, key properties, events, and methods. Many illustrative code examples are included. Students should be able to incorporate other GUI features on their forms. By moving the majority of the GUI discussion to the appendix, the main text can focus on algorithms and logic structures. An added benefit of this separate appendix is the increased flexibility for the instructor to cover specific GUI elements as appropriate and to cover different controls from semester to semester.
Appendix on Program Design and Translation to VB Code
Although the entire text uses a problem-solving approach, some instructors may find it useful to have a more thorough coverage of logic design in a separate section. Appendix B, "Program Design and Translation to VB Code," serves as a more complete reference for logic design concepts that employ flowcharts for visual illustrations. Furthermore, it includes a set of translation rules to convert design logic into corresponding Visual Basic code. For students who have already taken a problem-solving course, this appendix serves as a reference for the design standards used in this text. In other situations where an instructor wants to teach the logic design structures before doing any coding, or after learning a few basic coding statements, this appendix can be used as a teaching aid at the appropriate time of the semester, just like any other chapter. Finally, for students who follow the suggested process of design prior to coding, the list of translation rules can serve as a reference guide when they convert their program logic into Visual Basic code.
Object-Event Diagrams (OEDs)
Because Visual Basic is event-driven, where the code is written is as important as the code itself. Because this is not always obvious, particularly for people who do have experience with a traditional, structured programming language, the OED tool will help students think about the importance of the events, as well as document how their programs' procedures are organized. When following the recommended six step program development process, this tool provides students with a natural transition from user-interface development to macro-level logic design. The first level identifies the project, and the second level identifies GUI objects, all of which can be gleaned from the just-developed interface. The third level identifies the events that will resp...
