Traffic light and infinite loop countdown

Question

I have programmed a traffic light on visual basic 6.0 but I cant seem to program the countdown(10-0) to be on infinite loop at every light i.e it should countdown from 10 to 0 before each light shows. Here is my code

Private Sub Timer2_Timer()
    If Label1. Caption = 0 Then
        Timer2.Enabled = False
        MsgBox ("go")
    Else
        Label1. Caption = Label1. Caption - 1
    End If
End Sub

the countdown continues to 1,-2,-3,-4 and so on but I want it to start from 10 again after counting from 10 to 0. How do I put it on endless loop on visual basic 6.0

Answer 1

Instead of:

Timer2.Enabled = False

do something like:

Label1.Caption = 10

That way the timer will keep running forever, and will reset to 10 every time it reaches 0.

---

Also, to make the code a little more robust, you might take this approach:

Private Const maxCounter As Integer = 10
Private counter As Integer

Private Sub form_Load()
    counter = maxCounter
End Sub

Private Sub Timer2_Timer()
    If counter = 0 Then
        counter = maxCounter
        MsgBox ("go")
    Else
        counter = counter - 1
    End If

    Label1.Caption = counter

End Sub

One advantage is that your code does not depend on how you set the Caption property at design time. And secondly it is a little more modular and understandable in that the functional logic (how the counter is managed) and the display logic (how the caption is set) are mostly distinct.

Also, using a constant maxCounter just means you don't have to repeat the value in different places, and it can be changed easily without introducing discrepencies.

Obviously this is a small program but these are good programming principles to think about which benefit larger programs tremendously.