Visual Basic .NET - Variables and Constant

In programming, a variable is a named storage location in the computer's memory where a value can be stored and retrieved during program execution. It is used to store data that can be modified during the execution of the program. A constant, on the other hand, is a value that cannot be changed during program execution.

In VB.NET, to declare a variable, you use the Dim keyword, followed by the variable name and the data type. For example:

Dim myVariable As Integer

This declares a variable named myVariable of type Integer.

To declare a constant, you use the Const keyword, followed by the constant name and value. For example:

Const pi As Double = 3.14159

This declares a constant named pi with a value of 3.14159.

When working with variables and constants in VB.NET, there are a few rules to keep in mind:

• Variable and constant names must begin with a letter or underscore character, followed by any combination of letters, digits, or underscore characters.
• Variable and constant names cannot contain spaces or special characters, such as @, #, $, %, etc.
• Variable and constant names are case-insensitive, meaning that myVariable, MyVariable, and MYVARIABLE all refer to the same variable.
• Variables and constants must be declared before they can be used.
• Constants cannot be changed during program execution.