Declaring Visual Basic Variables and Constants

The different types of Visual Basic variables and constants was described in detail in the previous chapter (Understanding Visual Basic Variable & Constant Types). In this chapter we will learn how to declare and initialize variables and constants in Visual Basic.

Before learning how to declare variables and constants it is worth a quick reminder of the difference between variables and constants in Visual Basic. Both constants and variables provide a way to reserve memory locations for the storage of values of various types (such as numbers, characters and strings). These memory locations are assigned names which can be used in Visual Basic code to reference these memory locations. For example, you might want to store the interest rate for a banking application. To do so you would declare a variable with a name of your choice (such as interestRate) and specify the variable as an Interger type (since it will be storing a number). Having declared the variable you can assign a value to it and read that value anywhere in your application code.

The difference between variables and constants is that the value stored in a variable can be changed at any time after it has been created. The value assigned to a constants, as the name suggests, cannot be changed once it has been declared an initialized.