Olga Maria Stefania Cucaro - Programming in Visual Basic (VB)

PROGRAMMING IN VISUAL BASIC (VB) FROM THE ANALYSIS OF THE PROBLEM TO THE PROGRAM Of OLGA MARIA STEFANIA CUCARO Copyright 2021 by Olga MariaStefania Cucaro -All rights reserved. It is not permitted toreproduce, duplicate orsend any part of this document electronically or in print. Copyingofthis document is strictly prohibited. All the programs included inthis book are also copyrighted by the author / creator of thework. Dedicated to: Tomy mother who has always believed in me and to all the computerprofessors I have met in my life

This work was born from thenecessity found by theauthor to solve various problems repeated over time, concerning thedata inserted in Excel sheets in the shortest possible time. Theauthor, being a programmer and expert in Pascal, Cobol andJavascript, searched for the most suitable solution and found it inthe Excel VBA and in the Visual Studio VB.

This document isintended to introduce users to programming in general and toprogramming in Visual Basic in particular. The VB is simple and canbe used on existing csv files or data entered directly into VisualStudio, quickly processing a large amount of data. For the momenttheonly tool we need is Visual Studio and the csv files. Of course, Ican't go into the intricacies of the databases that I willdefinitelyinclude in a future book. The book may not contain everything you should know aboutprogrammingin VB, but it does point the finger at the key points to createsomeprograms which are explained in detail in the various chapters. Thecontent is divided into two parts one which explains programming ingeneral and the second which explains programming in VB withconcreteexamples of programs.

To see the programs inserted in this document in Excel VBA, I referyou to my other eBook "PROGRAMMING IN VBA".

The first step beforeprogramming is to understandthe problem to be solved with the program we are going tocreate. Just like in math, it is bestto think carefullybefore starting to solve the problem. For example, let's assume wework in a Call Center and have all the probable customers to becontacted periodically in an Excel sheet and all the customerscontacted in the single days of the twelve months of the year inanother sheet and we know that the customer must be contactedmaximum3 times a month, this is a problem that we can solve with the VB.Inparticular, to solve the problem we have to look for the names ofthefirst sheet in the second sheet and count how many times it isrepeated for each month, DATA that we will insert in the firstsheet.Subsequently we will carry out a check and if the value for eachmonth is greater than 3 we could decide to color the number in redtohighlight the problem. Another example could be tocalculate the hoursworked by each employee and the relative remuneration, obviouslyhaving in one sheet the name of the employee and the hourlyremuneration and in another sheet the hours worked in each singledayof the month. In this case we will search for the name entered inthefirst sheet in the second sheet and we will add the hours worked byeach individual employee and multiply them by the hourlywages.

We will solve these problems atthe end of thisbook after having better understood the basics of programming andVB,but the logic of the solution must be clear before tackling theprogramming step. Let's start with the simplestexample that is thesum of three numbers. What do we do automatically to addthreenumbers?

1. we read the three numbers
2. Let's add the three numbers
3. We write the result

Assumingto name the three numbers with A, B and C we will proceed asfollows:

1. Reset the Sum
2. Read A
3. Read B
4. Read C
5. Sum = A + B + C
6. Write Sum

Wehave simply divided the process into simple and sequentialoperations.

In the previous example we canidentify fourvariables, three of input (input) and one of output (output). Inparticular A, B and C are the input variables, while Sum is theoutput variable. If we used an intermediate variable we would callita working variable.

The difference between variables and constantsisessential, a constant says the word itself and already set at thebeginning of the program and does not change during processing, itremains constant. Variables are divided intointegers, reals andbooleans. Integer variables contain integers, real variablescontainreal numbers and Boolean variables contain two states (true orfalse) Why did I write contain?Precisely because thevariable is like a container and contains what weindicate. In all programming languagesthe first stepis the definition of the variables which makes the computer able torecognize them. In our simple little program,the sum of threenumbers A, B, C and Sum are numeric variables that can be integersatthe programmer's choice.

Thepseudo-code allows programming in a general language which is thendeclined in the individual languages by the programmer.

Thepseudo-code allows programming in a general language which is thendeclined in the individual languages by the programmer.

We cansimply say that a pseudo-language is a generic programming thatbecomes specific with the choice and use of the single language. Ifaprogrammer is a beginner, it is better to start by writing apseudo-code first and then transform this pseudo-code into theactualprogram in the chosen language.

Variables are of fundamentalimportance forprogramming. After having identified them, they must be defined atthe beginning of the program as we will see in the flow charts thatwe will use in the following chapters. Variables contain data andhave a unique name. The assignment, on the other hand, consists ingiving a certain value to the variable.