This book is written from a Visual basic open pdf Basic 6. 0 perspective although much of what is said is also valid for Visual Basic 5. 0 and Visual Basic 4.
It covers many different techniques and topics including object oriented programming, optimization of programs and coding guidelines. This book’s sole purpose is to help people better understand Visual Basic. A timeline of Visual Basic’s history. Introduction to calculating and operands with Visual Basic. Branching occurs when the program makes a decision. The flow of execution follows a particular branch like a fork in the road. Loops are control structures used to repeat a given section of code a certain number of times or until a particular condition is met.
They are very useful for communicating with human beings and for transferring data between programs and machines in text files and web pages. Strings can be manipulated using simple string functions. Complex string matching and manipulation can be achieved using a fairly sophisticated technique of regular expressions. Arrays are used to group data items of the same type together, to make it easier to search and sort through this data. Sets of key, value pairs. A datatype is a specification of the kind of information that a variable can hold, for example, a number or a piece of text. Errors can be caught, handled and raised.
While programming, you may want to at some point save data so they may be accessible for further use. Visual Basic allows us to perform most operations available in Windows Explorer and DOS command line. Dates and time need to be formatted, added, etc. Visual Basic supports creation of Graphical User Interfaces, which generally consists of one or more Forms that contain text boxes, labels, buttons, picture boxes, etc. Visual Basic can easily be used to draw simple graphics such as line drawings and diagrams. Visual Basic can connect to databases in many different ways. Visual Basic hides the details of all the messages that Windows sends to an application but you can get at them if you really need to.
Then you can do things that plain Visual Basic cannot. Sometimes you want to call another program from Visual Basic. There is a lot of complicated talk about Object Oriented Programming but in essence it is quite simple. It isn’t enough that the program work, you must be able to maintain it as well. Effective programmers can read their code as well as write it. An idiom is a sort of template or generic method of expressing an idea. In the same way that idioms in a human language make life easier for the both speaker and listener good idioms in computer programming make life easier for the programmer.
Naturally what is idiomatic in one language might not be in another. It is often desirable that your program not only does what you want it to do, but it also does it fast and with low memory footprint. Optimizing aims to improve the latter two requirements. This section contains a number of ready made code examples for your use. They vary from short snippets to complete modules and short demo applications.
A small, almost throwaway application that demonstrates that useful application do not need to be either large or complicated. This section summarizes the syntax of Visual Basic and describes all the key concepts that of Visual Basic. It also notes some features that exist in other languages but do not exist in Visual basic. Consistent style in coding helps everyone to maintain a program whether the maintainer is the original author or not. This section serves as guide to the commands that can be used in Visual Basic. Brief explanations of various important, difficult or otherwise interesting words and phrases with links to longer explanations in the body of the text. Please look here for anything obscure or difficult.