User Defined Data Types

1
User Defined Data Types

• The Type Statement

2
Creating Your Own Data Types

• You can combine variables of several different
  types to create user-defined types.
• User-defined types are useful when you want to
  create a single variable that holds several
  related pieces of information.

3
Creating Your Own Data Types

• You create a user-defined type with the Type
  statement, which must be placed in the
  Declarations section of a module.
• User-defined types can be declared as Private or
  Public with the appropriate keyword.

4
Type Statement

• Syntax
• Private Public Type varname
• elementname As type
• elementname As type
• . . .
• End Type

5
Type Statement Example

• Type EmployeeRecord
• ID As Integer
• Name As String
• Address As String
• Phone As Long
• HireDate As Date
• End Type
• Public Sub CreateRecord()
• Dim MyRecord As EmployeeRecord
• MyRecord.ID 12003
• End Sub

6
' Declarations (in a standard module). Public
Type SystemInfo CPU As String VideoColors As
Integer Cost As Currency PurchaseDate As
Variant End Type Public Sub CreateSystem() Dim
MySystem As SystemInfo MySystem.CPU Pentium
4 MySystem.VidoColors 256 MySystem.Cost
1800.00 MySystem.PurchaseDate 1/1/02 End
Sub
7
Private Sub cmdProcess_Click() picBox.Cls Dim
college As collegeData Call GetDat(college)
Call DisplayStatement(college) End Sub Private
Sub DisplayStatement(school As collegeData)
picBox.Print school.name " was founded in " _
school.yearFounded picBox.Print " in "
school.state End Sub Private Sub GetDat(school
As collegeData) school.name txtCollege.Text
school.state txtState.Text school.yearFounded
Val(txtYear.Text) End Sub
Public Type collegeData name As String 30
state As String 2 yearFounded As Integer End
Type
8
Dim arrDog(1 To 5) As Dog Dim Index As
Integer Private Sub cmdAddData_Click()
arrDog(Index).Breed txtBreed.Text
arrDog(Index).Color txtColor.Text
arrDog(Index).Age Val(txtAge.Text) Index
Index 1 'clear textboxes for new entry
txtBreed.Text "" txtColor.Text ""
txtAge.Text "" End Sub Private Sub
cmdPrintData_Click() For i 1 To 5
picOutput.Print arrDog(i).Breed " "
picOutput.Print arrDog(i).Color " "
picOutput.Print arrDog(i).Age Next i End
Sub Private Sub Form_Load() Index 1 End Sub
Public Type Dog Breed As String Color As
String Age As Integer End Type