Book Image

Visual Basic Quickstart Guide

By : Aspen Olmsted
Book Image

Visual Basic Quickstart Guide

By: Aspen Olmsted

Overview of this book

Whether you’re an absolute beginner or an experienced developer looking to learn the Visual Basic language, this book takes a hands-on approach to guide you through the process. From the very first chapters, you'll delve into writing programs, exploring core concepts such as data types, decision branching, and iteration. Additionally, you’ll get to grips with working with data structures, file I/O, and essential object-oriented principles like inheritance and polymorphism. This book goes beyond the basics to equip you with the skills to read and write code across the entire VB family, spanning VB Script, VBA, VB Classic, and VB.NET, enabling you to handle legacy code maintenance with ease. With clear explanations, practical examples, and hands-on exercises, this book empowers you to tackle real-world software development tasks, whether you're enhancing existing projects or embarking on new ones. It addresses common challenges like distinguishing between the variations of the VB programming language to help you choose the right one for your projects. Don't let VB's extensive legacy daunt you; embrace it with this comprehensive guide that equips you with practical, up-to-date coding skills to overcome the challenges presented by Visual Basic's rich history of over two decades.
Table of Contents (27 chapters)
Free Chapter
1
Part 1:Visual Basic Programming and Scripting
9
Part 2:Visual Basic Files and Data Structures
14
Part 3:Object-Oriented Visual Basic
20
Part 4:Server-Side Development

The VB.NET AndAlso operator

In VB.NET, the AndAlso operator is a logical operator used with If statements to evaluate multiple conditions. The AndAlso operator is similar to the And operator, but it provides short-circuit evaluation.

The basic syntax for using the AndAlso operator in an If statement is as follows:

If condition1 AndAlso condition2 Then
   ' code to execute if both conditions are true
End If

In the preceding example, the code block will be executed if both condition1 and condition2 are true. However, unlike the And operator, the AndAlso operator provides short-circuit evaluation, which means that if condition1 is false, condition2 will not be evaluated. Short-circuiting can improve performance in situations where considering condition2 is expensive or time-consuming.

Here’s an example that demonstrates the use of the AndAlso operator:

Dim var1 As Integer = 4
Dim var2 As Integer = 8
If var1 >= 4 AndAlso var2 < 8 Then
 ...