Lesson 7: Mastering If Statements and IIf() Function

If condition Then
    ' Code to execute if condition is true
ElseIf anotherCondition Then
    ' Code to execute if another condition is true
Else
    ' Code to execute if no conditions are true
End If

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 successful")
    ElseIf UsrTxt.Text <> username Or pwTxt.Text <> password Then
        MsgBox ("Sign in failed")
    End If
End Sub

Private Sub cmdCalComm_Click()
    Dim salevol, comm As Currency
    salevol = Val(TxtSaleVol.Text)

    If salevol >= 5000 And salevol < 10000 Then
        comm = salevol * 0.05
    ElseIf salevol >= 10000 And salevol < 15000 Then
        comm = salevol * 0.1
    ElseIf salevol >= 15000 And salevol < 20000 Then
        comm = salevol * 0.15
    ElseIf salevol >= 20000 Then
        comm = salevol * 0.2
    Else
        comm = 0
    End If

    LblComm.Caption = Format(comm, "$#,##0.00")
End Sub

Private Sub CalculateGrade_Click()
    Dim score As Integer
    Dim grade As String

    score = Val(txtScore.Text)

    If score >= 90 Then
        grade = "A"
    ElseIf score >= 80 Then
        grade = "B"
    ElseIf score >= 70 Then
        grade = "C"
    ElseIf score >= 60 Then
        grade = "D"
    Else
        grade = "F"
    End If

    lblGrade.Caption = "Grade: " & grade
End Sub

Dim result = IIf(condition, valueIfTrue, valueIfFalse)

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

Private Sub ShowStatus_Click()
    Dim isLoggedIn As Boolean
    Dim statusMessage As String

    ' Check login status (in real app, this would come from authentication)
    isLoggedIn = (txtUsername.Text = "admin" And txtPassword.Text = "secret")

    ' Use IIf to determine status message
    statusMessage = IIf(isLoggedIn, _
        "Welcome " & txtUsername.Text & "! You are logged in.", _
        "Login failed. Please check your credentials.")

    lblStatus.Caption = statusMessage
End Sub