01.Public Class Form2
02.
03. Private Sub Form2_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
04. ListBox1.Items.Add("For Next")
05. ListBox1.Items.Add("Do While Loob")
06. ListBox1.Items.Add("Do Loob Until")
07. ListBox1.Items.Add("Do Loob While")
08. End Sub
09. Sub Result()
10. Dim a As Int32
11. Dim fac As Int32 = 1
12. Dim i As Int32
13. a = Val(TextBox1.Text)
14. For i = a To 1 Step -1
15. fac = fac * i
16. Next
17. Label5.Text = fac
18. End Sub
19. Sub Resule1()
20. Dim a1 As Int32
21. Dim fac1 As Int32 = 1
22. Dim i1 As Int32 = 1
23. a1 = Val(TextBox1.Text)
24.
25. Do While a1 >= i1
26. fac1 = fac1 * i1
27. i1 = i1 + 1
28. Loop
29. Label5.Text = fac1
30. End Sub
31. Sub Resule2()
32. Dim a2 As Int32
33. Dim fac2 As Int32 = 1
34. Dim i2 As Int32 = 1
35. a2 = Val(TextBox1.Text)
36. Do
37. fac2 = a2 * i2
38.
39. i2 = i2 + 1
40.
41. Loop Until a2 >= i2
42. Label5.Text = fac2
43.
44. End Sub
45. Sub Resule3()
46.
47. Dim i3 As Integer = 1
48. Dim a3 As Integer
49. Dim fac3 As Integer = 1
50. a3 = Val(TextBox1.Text)
51. Do
52.
53. fac3 = fac3 * i3
54. i3 = i3 + 1
55.
56. Loop While a3 >= i3
57.
58. Label5.Text = fac3
59.
60.
61.
62. End Sub
63.
64. Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
65. If ListBox1.Text = "For Next" Then
66. Call Result()
67. ElseIf ListBox1.Text = "Do While Loob" Then
68. Call Resule1()
69. ElseIf ListBox1.Text = "Do Loob Until" Then
70. Call Resule2()
71. ElseIf ListBox1.Text = "Do Loob While" Then
72. Call Resule3()
73. End If
74. End Sub
75.
76. Private Sub ListBox1_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ListBox1.SelectedIndexChanged
77.
78. End Sub
79.End Class
