傳入三個參數的副程式

編號	程式碼	說明
1	Public Class Form1
2	Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
3	Call mycomp("+", 1, 2)	'呼叫副程式做加總動作
4	Call mycomp("-", 1000, 100)	'呼叫副程式做減法動作
5	Call mycomp("*", 5, 3)	'呼叫副程式做乘法動作
6	Call mycomp("/", 10, 2)	'呼叫副程式做除法動作
7	Call mycomp("/", 10, 0)
8	End Sub
9	Sub mycomp(ByVal op, ByVal a, ByVal b)	'計算與結果輸出副程式
10	If op = "+" Then MsgBox(a & "+" & b & "=" & a + b)
11	If op = "-" Then MsgBox(a & "-" & b & "=" & a - b)
12	If op = "*" Then MsgBox(a & "*" & b & "=" & a * b)
13	If op = "/" Then
14	If b = 0 Then	'處理除數為0狀況
15	MsgBox("除數不能為0")
16	Else
17	MsgBox(a & "/" & b & "=" & a / b)
18	End If
19	End If
20	End Sub
21	End Class