User-Defined Data Types

In this section, you will learn how to create your own data types.

The user-defined data types are sometimes called structures and records.

You use the type statement to create your own data types. The format is as follows:

[Private | Public] Type varname
elementname [([subscripts])] As type
[elementname [([subscripts])] As type]
. . .
End Type

Notice that the name of the user-defined data type you want to create follows the Type keyword. If you've already declared a variable named Student, for instance, you can't create a user defined data type named Student.

You must declare all user-defined types at the module level. It's invalid to declare them inside procedures. You can declare a type in a form module, but it must be declared as Private.

Examine the following code to learn more about the Type statement:

Type EmployeeName
    First As String
    Last As String
End Type
Public emp As EmployeeName

The above code declares a user defined data type named EmployeeName. The following code initializes and work with the variable just created.

emp.First = "Sachin"
emp.Last = "Tendulkar"

To limit the size of string variables used in the structure, you can add the * StringLength option. For example,

Type EmployeeName
    First As String * 15
    Last As String * 15
End Type