Lesson 13: Using Select Case

The Select Case control structure also involves decisions making but it is slightly different from the If...Then...ElseIf control structure . The If ...Then...ElseIf statement control structure evaluates only one expression but each ElseIf statement computes different values for the expression. On the other hand, the Select Case control structure evaluates one expression for multiple values. Select Case is preferred when there exist multiple conditions as using If...Then...ElseIf statements will become too messy.

The syntax is as follow

Select Case variable
 Case value 1
  Statement
 Case value 2
  Statement
 Case value 3
  Statement
 Case value 4
  Statement
 Case Else
End Select

In the following example, we shall show you how to process the grades of students according to the marks given.

Private Sub CommandButton1_Click()

 Dim mark As Single
 Dim grade As String
 mark = Cells(1, 1).Value
 Range("A1:B1").Select
 With Selection
  .HorizontalAlignment = xlCenter
 End With
 Select Case mark
  Case 0 To 20
   grade = "F"
   Cells(1, 2) = grade
 Case 20 To 29 
   grade = "E" 
   Cells(1, 2) = grade 
 Case 30 To 39
   grade = "D" 
   Cells(1, 2) = grade 
 Case 40 To 59 
   grade = "C" 
   Cells(1, 2) = grade 
 Case 60 To 79 
   grade = "B" 
   Cells(1, 2) = grade 
 Case 80 To 100 
   grade = "A" 
   Cells(1, 2) = grade 
 Case Else 
   grade = "Error!" 
   Cells(1, 2) = grade 
 End Select 
  
End Sub
 

You should also include the error case where the values entered are out of the range or invalid. For example, if the examination mark is from 0 to 100, then any value out of this range is invalid. In this program, we use case else to handle the error entries.The Figure below shows the output of this example.