Azri's Calculator

'In the name of ALLAH
'Name : Muhammad Azri bin Jasni @ Abdul Rani
'ID   : 2009147897
'Group: CS1105A
'Features:
'      Have Digits buttons, cmd# (# represent 0-9)
'      Operators buttons,cmdAdd,cmdMinus,cmdMulti,cmdDivide
'      Decimal Point, cmdDot
'      Calculate button, cmdEnter
'      Result display area, txtResult
'      Clear Button/CLEAR, cmdClear
'      Close button/BYE, cmdExit
'      Divide by Zero error will be told in the result display area (Math Error)
'      Multiple click of operator button doesn't change the memory of first operator pressed
'Known Bugs:
'      Other errors is not handled yet.
'      Didn 't handle situation where decimal point button pressed for an existing double type answer
'      No limit of digits yet
Option Explicit
Dim result As Double
Dim memory As Double
Dim tempResult As Double
Dim operator As Integer '0 for Default, 1 for Add, 2 for Minus, 3 for Multiply, 4 for Divide
Dim dotCounter As Integer

'Numbers
Private Sub cmd0_Click()
    If txtResult.Text = "Math Error" Then
        txtResult.Text = "Press Clear to Continue"
    ElseIf txtResult.Text = "Press Clear to Continue" Then
        txtResult.Text = "Press Clear to Continue"
    ElseIf operator <> 0 Then
        txtResult.Text = "0"
    ElseIf txtResult.Text <> "0" Then
        txtResult.Text = txtResult.Text & "0"
    End If
End Sub

Private Sub cmd1_Click()
    If txtResult.Text = "Math Error" Then
        txtResult.Text = "Press Clear to Continue"
    ElseIf txtResult.Text = "Press Clear to Continue" Then
        txtResult.Text = "Press Clear to Continue"
    ElseIf txtResult.Text = "0" Then
        txtResult.Text = "1"
    Else: txtResult.Text = txtResult.Text + "1"
    End If
End Sub

Private Sub cmd2_Click()
    If txtResult.Text = "Math Error" Then
        txtResult.Text = "Press Clear to Continue"
    ElseIf txtResult.Text = "Press Clear to Continue" Then
        txtResult.Text = "Press Clear to Continue"
    ElseIf txtResult.Text = "0" Then
        txtResult.Text = "2"
    Else: txtResult.Text = txtResult.Text + "2"
    End If
End Sub

Private Sub cmd3_Click()
    If txtResult.Text = "Math Error" Then
        txtResult.Text = "Press Clear to Continue"
    ElseIf txtResult.Text = "Press Clear to Continue" Then
        txtResult.Text = "Press Clear to Continue"
    ElseIf txtResult.Text = "0" Then
        txtResult.Text = "3"
    Else: txtResult.Text = txtResult.Text + "3"
    End If
End Sub

Private Sub cmd4_Click()
    If txtResult.Text = "Math Error" Then
        txtResult.Text = "Press Clear to Continue"
    ElseIf txtResult.Text = "Press Clear to Continue" Then
        txtResult.Text = "Press Clear to Continue"
    ElseIf txtResult.Text = "0" Then
        txtResult.Text = "4"
    Else: txtResult.Text = txtResult.Text + "4"
    End If
End Sub

Private Sub cmd5_Click()
    If txtResult.Text = "Math Error" Then
        txtResult.Text = "Press Clear to Continue"
    ElseIf txtResult.Text = "Press Clear to Continue" Then
        txtResult.Text = "Press Clear to Continue"
    ElseIf txtResult.Text = "0" Then
        txtResult.Text = "5"
    Else: txtResult.Text = txtResult.Text + "5"
    End If
End Sub

Private Sub cmd6_Click()
    If txtResult.Text = "Math Error" Then
        txtResult.Text = "Press Clear to Continue"
    ElseIf txtResult.Text = "Press Clear to Continue" Then
        txtResult.Text = "Press Clear to Continue"
    ElseIf txtResult.Text = "0" Then
        txtResult.Text = "6"
    Else: txtResult.Text = txtResult.Text + "6"
    End If
End Sub

Private Sub cmd7_Click()
    If txtResult.Text = "Math Error" Then
        txtResult.Text = "Press Clear to Continue"
    ElseIf txtResult.Text = "Press Clear to Continue" Then
        txtResult.Text = "Press Clear to Continue"
    ElseIf txtResult.Text = "0" Then
        txtResult.Text = "7"
    Else: txtResult.Text = txtResult.Text + "7"
    End If
End Sub

Private Sub cmd8_Click()
    If txtResult.Text = "Math Error" Then
        txtResult.Text = "Press Clear to Continue"
    ElseIf txtResult.Text = "Press Clear to Continue" Then
        txtResult.Text = "Press Clear to Continue"
    ElseIf txtResult.Text = "0" Then
        txtResult.Text = "8"
    Else: txtResult.Text = txtResult.Text + "8"
    End If
End Sub

Private Sub cmd9_Click()
    If txtResult.Text = "Math Error" Then
        txtResult.Text = "Press Clear to Continue"
    ElseIf txtResult.Text = "Press Clear to Continue" Then
        txtResult.Text = "Press Clear to Continue"
    ElseIf txtResult.Text = "0" Then
        txtResult.Text = "9"
    Else: txtResult.Text = txtResult.Text + "9"
    End If
End Sub
'Operators
Private Sub cmdAdd_Click()
    If txtResult.Text = "Math Error" Then
        txtResult.Text = "Press Clear to Continue"
    ElseIf txtResult.Text = "Press Clear to Continue" Then
        txtResult.Text = "Press Clear to Continue"
    ElseIf operator <> 0 Then
    Else:
        memory = txtResult.Text
        txtResult.Text = ""
        operator = 1
    End If
End Sub

Private Sub cmdMinus_Click()
    If txtResult.Text = "Math Error" Then
        txtResult.Text = "Press Clear to Continue"
    ElseIf txtResult.Text = "Press Clear to Continue" Then
        txtResult.Text = "Press Clear to Continue"
    ElseIf operator <> 0 Then
    Else:
    memory = txtResult.Text
    txtResult.Text = ""
    operator = 2
    End If
End Sub

Private Sub cmdMulti_Click()
    If txtResult.Text = "Math Error" Then
        txtResult.Text = "Press Clear to Continue"
    ElseIf txtResult.Text = "Press Clear to Continue" Then
        txtResult.Text = "Press Clear to Continue"
    ElseIf operator <> 0 Then
    Else:
    memory = txtResult.Text
    txtResult.Text = ""
    operator = 3
    End If
End Sub

Private Sub cmdDivide_Click()
    If txtResult.Text = "Math Error" Then
        txtResult.Text = "Press Clear to Continue"
    ElseIf txtResult.Text = "Press Clear to Continue" Then
        txtResult.Text = "Press Clear to Continue"
    ElseIf operator <> 0 Then
    Else:
    memory = txtResult.Text
    txtResult.Text = ""
    operator = 4
    End If
End Sub

Private Sub cmdClear_Click()
    result = 0
    txtResult.Text = 0
    operator = 0
    tempResult = 0
End Sub

Private Sub cmdDot_Click()
    If txtResult.Text = "Math Error" Then
        txtResult.Text = "Press Clear to Continue"
    ElseIf txtResult.Text = "Press Clear to Continue" Then
        txtResult.Text = "Press Clear to Continue"
    ElseIf dotCounter = 0 Then
        txtResult.Text = txtResult.Text + "."
        dotCounter = 1
    End If
End Sub

Private Sub cmdEnter_Click()
    If txtResult.Text = "Math Error" Then
        txtResult.Text = "Press Clear to Continue"
    ElseIf txtResult.Text = "Press Clear to Continue" Then
        txtResult.Text = "Press Clear to Continue"
    Else
        tempResult = txtResult.Text
        If operator = 0 Then
            txtResult.Text = tempResult
        ElseIf operator = 1 Then
            txtResult.Text = memory + tempResult
        ElseIf operator = 2 Then
            txtResult.Text = memory - tempResult
        ElseIf operator = 3 Then
            txtResult.Text = memory * tempResult
        ElseIf operator = 4 Then
            If tempResult = 0 Then
                txtResult.Text = "Math Error"
            Else:
                txtResult.Text = memory / tempResult
            End If
        End If
    End If
    memory = 0
    operator = 0
    dotCounter = 0

End Sub

'Exit
Private Sub cmdExit_Click()
 End
End Sub