Objectives Machine language vs.. High-level language Procedure-oriented, object-oriented, and event- driven languages Background of Visual Basic VB Integrated Development Environment Online documentation and Help features

Software Application Software – Word Processors – Database s/w – Spreadsheets – Painting programs – Web browsers, programs System Software – Operating Systems Windows Macintosh OS Unix Linux – Drivers Software is comprised of instructions that get a computer to perform a task.

Software Computer Hardware Processing Unit Output Unit Input Unit Memory Unit System Software Application Software Operating System Language Processor Utility Software General Software Customized Software

Exploring MS Visual Basic 6Copyright 1999 Prentice-Hall, Inc.4 Application Programs Program - detailed set of instructions for a computer to execute Application programs (applications or apps) - self- contained collection of programs that perform a task for the end user Programming language - formal language used to give instructions to computers

Programming Languages Programming languages allow programmers to code software. The three major families of languages are: – Machine languages – Assembly languages – High-Level languages

Software Collection of Programs Set of Commands ( Pre Defined ) Programming Language Programmer

Exploring MS Visual Basic 6Copyright 1999 Prentice-Hall, Inc.7 History of Programming Languages Machine language Procedure-oriented languages Object-oriented languages Event-driven languages Natural languages

Exploring MS Visual Basic 6Copyright 1999 Prentice-Hall, Inc.8 History of Programming Languages Machine Language – different for each computer processor Procedure-Oriented Languages – FORTRAN – COBOL – Pascal – C – Ada

Exploring MS Visual Basic 6Copyright 1999 Prentice-Hall, Inc.9 History of Programming Languages Object-oriented languages – Smalltalk – C++ – Ada 95 Event-driven languages – Visual Basic – most Visual languages

Exploring MS Visual Basic 6Copyright 1999 Prentice-Hall, Inc.10 History of Programming Languages Natural languages – computer will accept a user’s native or natural language, such as English – Researchers continue to work in this area

VISUAL BASIC

Why VB? Rationale… Easy for beginners to produce a working program Capable of high end programs Graphical OOP (for the most part) Affordable Many free resources available 12

Exploring MS Visual Basic 6Copyright 1999 Prentice-Hall, Inc.13 Background of Visual Basic BASIC – Beginner’s All-purpose Symbolic Instruction Code – By John Kemeny and Thomas Kurtz – Designed to teach programming to beginners – BASIC language interpreter, one of Microsoft’s first products

Exploring MS Visual Basic 6Copyright 1999 Prentice-Hall, Inc.14 Background of Visual Basic BASIC – Beginners' All purpose Symbolic Instruction Code – Included with DOS – QBASIC - included with DOS Version 5 - subset of BASIC Visual Basic – Visual Basic 1 for Windows 3 – Visual Basic 4 - for Windows 95 – Visual Basic 5 - for Office 97 – Visual Basic 6 - for Windows 98 & Office 2000

VISUAL BASIC GUI – (Graphical user interface )Graphical user interface IDE – (Integrated development environment)Integrated development environment EDP – (Event Driven Programming)Event Driven Programming

The GUI environment is event-driven An event is an action that takes place within a program – Clicking a button (a Click event) – Keying in a TextBox (a TextChanged event) Visual Basic controls are capable of detecting many, many events A program can respond to an event if the programmer writes an event procedure Slide Event Driven Programming: Events

Starting VB 6.0 Go to Start All Programs Microsoft Visual Studio 6.0 Microsoft Visual Basic 6.0 Select

Exploring MS Visual Basic 6Copyright 1999 Prentice-Hall, Inc.18 Toolbox Form Designer Window Code Editor Window Project Explorer Properties window Form Layout Window Visual Basic 6 Interactive Development Environment

Elements of the Integrated Development Environment Application icon Application name Context menus Controls Current project Design view mode Title bar Major windows – Form Designer – Form Layout – Toolbox – Project Explorer – Object Browser – Properties – Code Editor – Immediate, Locals, Watch