Declaring named constants

As we have seen, you can use a constant in an expression by merely writing its literal value. (Such constants are called literals).

If you are going to use a constant in several places within a program, you can declare it, giving it a name and data type, using the Private statement (you cannot use Dim with named constants):

   Private const <constant name> as <data type> = <value>

For example:

   Private Const votingAge As Integer = 18
   Private Const homeState As String = "California"
   Private Const taxRate As Single = .22

Once declared, you can use a named constant as many times as you wish. This is handy if you decide you need to change its value at a later time. For example, if the votingAge, homeState or taxRate were to change in the above snippet, you would only have to change the declaration. Named constants also make a program more readable.

If you forget the type of a constant (or variable), place the cursor over it, and a popup box will give its data type.

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