ໃນບົດຮຽນກ່ອນ ພວກເຮົາໄດ້ຮຽນກ່ຽວກັບວິທີການຂຽນໂຄດໃນ Visual basic 6 ແຕ່ໃນບົດນີ້ແມ່ນຮຽນຮູ້ ກ່ຽວກັບ ການນຳໃຊ້ if ແລະ iff() function
1. Conditional Operators
ແມ່ນເຄື່ອງໝາຍສະແດງເຖິງເງື່ອນໄຊໜຶ່ງທີ່ໃຊ້ ໃນ Visual Basic 6
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2. Logical Operators
ເປັນເງື່ອນໄຂເພີ່ມໃນ Visual Basic 6
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3 ການໃຊ້ If…..Then…..Else ກັບ Operators
ຕົວຢ່າງແບບຂຽນໂຄດ
If conditions Then VB expressions Else VB expressions End If
ຂ້າງລຸ່ມນີ້ເປັນຕົວຢ່າງໂປຣແກຣມ ໃຊ້ If…..Then…..Else ກັບ Operators
Private Sub OK_Click()
Dim username, password As String
username = "John123"
password = "qwertyupi#@"
If UsrTxt.Text = username And pwTxt.Text = password Then
MsgBox ("Sign in sucessful")
ElseIf UsrTxt.Text <> username Or pwTxt.Text <> password Then
MsgBox ("Sign in failed")
End If
End Sub
ຜົນໄດ້ຮັບ
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4. ການໃຊ້ IIf() Function
ມີຮູບແບບໂຄດ
IIf(x, y, z)
IIF(x>y, expression 1, expression 2) function ຈະປະເມີນຄ່າຂອງ x ແລະ y, ຖ້າ x>y. ເມື່ອນັ້ນ expression 1 ເປັນ true, ຖ້າບໍ່ດັ່ງນັ້ນ expression 2 ແມ່ນ true ເໝືອນກັນ
ຕົວຢ່າງ:
Private Sub CmdNumeric_Click()
Dim x, y, a, b, ans As Double
x = InputBox("Enter a number")
y = InputBox("Enter another number")
a = Val(x)
b = Val(y)
ans = IIf(a < b, b - a, a * b)
MsgBox ans
End Sub
Private Sub CmdString_Click()
Dim A, B, C As String
A = InputBox("Enter a word")
B = InputBox("Enter another word")
C = IIf(A < B, A, B)
MsgBox C
End Sub
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