Computer Programming Concepts and Visual Basic David I. Schneider

250 Computer Programming Concepts and Visual Basic
EXAMPLE 4
The following program uses Sub procedures to perform the same tasks as the program in Example 3.
‘In BAS Module
Public Type collegeData
nom As String * 30
state As String * 2
yearFounded As Integer
End Type
‘In Form code
Private Sub cmdProcess_Click()
‘Demonstrate use of records
picBox.Cls
Dim college As collegeData
Call GetDat(college)
Call DisplayStatement(college)
End Sub
Private Sub DisplayStatement(school As collegeData)
Dim century As Integer, when As String
century = 1 + Int(school.yearFounded / 100)
picBox.Print RTrim(school.nom); “ was founded in the” & Str(century);
picBox.Print “th century in ”; school.state
Dim university As collegeData
university.nom = “M.I.T.”
university.state = “MA”
university.yearFounded = 1878
If school.yearFounded < university.yearFounded Then
when = “before ”
Else
when = “after ”
End If
picBox.Print RTrim(school.nom); “ was founded ”;
picBox.Print when; RTrim(university.nom)
End Sub
Private Sub GetDat(school As collegeData)
school.nom = txtCollege.Text
school.state = txtState.Text
school.yearFounded = Val(txtYear.Text)
End Sub
COMMENTS
1. Record variables are similar to arrays in that they both store and access data items
using a common name. However, the elements in an array must be of the same
data type, whereas the fields in a record variable can be a mixture of different data
types. Also, the different elements of an array are identified by their indices,
whereas the fields of a record are identified by a name following a period.
2. If the record variables recVar1 and recVar2 have the same type, then all the field
values of recVar2 can be assigned simultaneously to recVar1 by the statement
recVar1 = recVar2