Introduction to Visual Basic

Previously, you were able to create a working Windows application with just a few mouse clicks. In this lesson, you'll find out what Visual Basic did behind the scenes to help you create that application. You'll also learn about properties, which are characteristics of an object—such as its size and color—and how to change those properties.

Windows applications are all about events, such as the event a user causes by clicking a button in the application. In this lesson, you'll first learn about event procedures. Then, you'll get your feet wet in Visual Basic by writing your first code.

So far, the lessons have focused on the form, which is perhaps the most important part of a Windows application's graphical user interface (or GUI). However, a form's primary role is to host other controls that enrich the GUI of Windows applications—menus, toolbars, buttons, text boxes, and list boxes. In this lesson, you'll find out how to add controls to your form and how to write code for these controls.

Most computer programs store information, or data. In this lesson, you'll learn all about data types, which represent different varieties of data (such as numeric data or text data). Then, the lesson will go over how to store that information in a variable.

Chess players marvel at the ability of computers to play world champion chess players on even terms. But once you understand that computers can calculate far more quickly and accurately than people can, it's easy to see how they're able to outplay the best players. In this lesson, you'll discover how to harness the computer's calculating ability using arithmetic operators.

As your programs become more sophisticated, they'll often branch in two or more directions based on whether a condition is true or false. For example, a calculator first needs to determine whether the user chose addition, subtraction, multiplication, or division before performing the indicated arithmetic. In this lesson, you'll see how to use comparison and logical operators to determine a user's choice.

Once you know the user's choice, you'll want to execute different code based on that choice. In this lesson, you'll learn how to use If and Select Case statements to execute alternative code statements.

When you were a child, your parents may have told you not to repeat yourself. But sometimes your code needs to repeat itself. For example, if your application's users enter invalid data, your code may continue to ask whether they want to retry or quit until they either enter valid data or quit. In this lesson, you'll explore how to use loops, which repeat code execution until a condition is no longer true. Then, you'll delve into arrays, which may hold multiple values at one time and work very well with loops.

Many textbooks are several hundred pages long. Imagine how much harder a textbook would be to understand if it consisted of only one very long chapter, rather than being divided into manageable sections. Thankfully, chapters organize books into manageable chunks of information. In this lesson, you'll learn how to similarly divide up your code into separate procedures and then explore two types of procedures—subroutines and functions—that help you organize your code.

When you finish writing something, you probably close your word-processing program and might even shut down your computer. Of course, the next time you don't have to start over; what you wrote before is preserved. However, up until now, your programs haven't saved data so that it's available even after the application exits. This lesson will discuss how to write code that reads from and writes to a text file in order to preserve the data. You'll also learn how to add Open and Save dialog boxes, such as those used in sophisticated programs like Microsoft Word, so that you can open a text file to read from it and save to a text file to write to it.

Nobody's perfect, right? Well, your applications won't always run perfectly either. Sometimes they'll stop due to a runtime error, also called an exception. In the final lesson, you'll find out how to prevent and handle exceptions.