VB-64 : Simple Calculator

Develop an application to design a simple calculator that performs the operations +,-,*,/, % , and Modulo operation.


To get an idea , Click  Simple Programs(3)


Refer The four calculations  , Calculations using Grid control  and Basic Mathematical functions also.

(A)Program Design : 

(B) Property(Controls Used) :

• One TextBox (Name-Text1) to input values as well as calculated output
• 4 Command Buttons with Captions as  .(Name-cmd_dot) , +/-(Name-cmd_sign)  , =(Name-com_equal)  , C(Name-com_cancel) 
• 10 Command Buttons with Name-Command1, Captions from 0 to 9 , Index from 0 yo 9
• 6 Command Buttons with Index from 0 to 5 , Text Property as /, * ,- , + , mod ,  % respectively and Name as com_op 

Note that , there is only one Text Box and 20 Command Buttons.

 (C) Attaching Code to the Object :

                

Dim old As String Dim old2 As String Dim op As String Dim op2 As String Dim f As Integer

Private Sub calc_per() If op2 = "%" Then old_value = Val(old) Text1.Text = Val(old_value * (Val(Text1.Text) / 100)) f = 1 End If End Sub

Private Sub calc_text() Dim ans As Double Dim old_val As Double old_value = Val(old) Select Case op Case "+" ans = old_value + Val(old2) Case "-" ans = old_value - Val(old2) Case "*" ans = old_value * Val(old2) Case "/" Case "mod" ans = old_value - (CInt(old_value / Val(old2)) * Val(old2)) End Select Text1 = Str(ans) old = Text1 End Sub

Private Sub cmd_dot_Click() Text1 = Text1 & "." End Sub

Private Sub cmd_sign_Click() Text1.Text = -1 * Val(Text1.Text) End Sub

Private Sub com_cancel_Click() Text1.Text = "" old = "" op = "" op2 = "" End Sub

Private Sub com_equal_Click() If op2 = "=" Then Else old2 = Text1.Text End If calc_text f = 1 op2 = "=" End Sub

Private Sub cmd_op_Click(Index As Integer) If com_op(Index).Caption = "%" Then op2 = "%" calc_per Else If op <> "" And op2 <> "=" Then old2 = Text1.Text calc_text End If old = Text1.Text op = com_op(Index).Caption f = 1 End If op2 = "" End Sub

Private Sub Command1_Click(Index As Integer) If f = 1 Then Text1 = Command1(Index).Caption Else Text1 = Text1 & Command1(Index).Caption End If f = 0 End Sub

Private Sub Form_KeyPress(KeyAscii As Integer) MsgBox KeyAscii End Sub Private Sub Form_Load() old = "" old2 = "" op = "" f = 0 End Sub

Private Sub Text1_KeyPress(KeyAscii As Integer) If ((KeyAscii >= 48 And KeyAscii <= 57) Or KeyAscii = 8 Or KeyAscii = 46 Or                                                                                                           KeyAscii = 27) Then                                                          Else KeyAscii = 8 End If End Sub

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VB-63 : Sum of the first n terms of the series

Develop an application to compile the Sum of the first n terms of the series :
S=1-3+5-7+9- .......

(A)Program Design : 

(B) Property(Controls Used) :

• 3 labels with Captions as S=1-3+5-7+9- ....... , Terms & Generate
• 2 Text Boxes
• One Command Button with Caption Generate

(C) Attaching Code to the Object :

Private Sub Command1_Click() Dim sum, j, i As Integer On Error GoTo error Text2 = "" sum = 0 j = 1 For i = 1 To Int(Text1.Text) sum = sum + j If (j > 0) Then If (i <> 1) Then Text2 = Text2 + "+" + Str(j) Else Text2 = Text2 + " " + Str(j) End If j = -(j + 2) Else Text2 = Text2 + " " + Str(j) j = -j + 2 End If Next Text2 = "Series is..." + vbCrLf + Str(sum) + "=" + Text2 error: End Sub

(D) Output :

Also refer Sum of n numbers .

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VB-62 : Convert Text from Lower case to Upper case

Develop an application to convert a given Text from Lower case to Upper case

Refer Convert Text from Upper case to Lower case .


The only difference lies in the code.


(Don't forget to change the Program Design as given):

Private Sub Text1_Change(0 Text2 = UCase(Text1) End Sub

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VB-61 : Displaying Current Date and Time

Develop an application to display current date and time on a form

 Refer Displaying Day for a given date also.

(A)Program Design : 

(B) Property(Controls Used) :

• 2 Labels with Captions Date & Time
• 3 TextBoxes  : Locked - True,BackColor-Gray,Text Property-Blank
• One Command Button (Caption - Current Time)

(C) Attaching Code to the Object :

Private Sub Command1_Click() Text1 = Format(Date, "dd/MM/yy") Text2 = Format(Date, "dddd,mmmm, d yyyy") Text3 = Time End Sub

Private Sub Form_Load() Call Command1_Click End Sub

(D) Output :

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Vb-60 : Count +ve & -ve from a list of number

Develop a small application that reads list of "n" numbers and makes a count of the number of negatives and non-negatives in it and displays them separately.

(A)Program Design : 

(B) Property(Controls Used) :

• 3 Text Boxes (Name-Text1,Text2 & Text3) , Multiline-True, Locked-True.
• 3 Labels with Captions Input Numbers,Negative Numbers & Non-Negative  Numbers
• 3 more Labels needed near to each Text Box to show the total number of input values , -ve numbers and  +ve numbers (Name - lbl_total , lbl_neg & lbl_pos) , and Captions Zero.
• One Command Button with Caption "Read a Number"

(C) Attaching Code to the Object :

Private Sub Command1_Click() no = InputBox("Enter A Number", "Input") On Error GoTo Error n1 = CSng(no) Text1 = Text1 + " " + no lbl_total = Int(lbl_total) + 1 If (n1 >= 0) Then Text3 = Text3 + " " + no p = p + 1 lbl_pos.Caption = Str(p) Else Text2 = Text2 + " " + no n = n + 1 lbl_neg.Caption = Str(n) End If Error: End Sub

Private Sub Form_Load() n = 0 p = 0 lbl_total = 0 lbl_pos = 0 lbl_neg = 0 End Sub

(D) Output :

 Click the Command Button Read A Number  

And enter any number in the dialog box appeared

Here, I entered 2 ,  2 is Positive , so it goes to the text box of positive numbers.

Again , Click the Read A Number command Button , and repeat the process..

Here, I entered numbers 3 times ( 2 , -6 , 80 ) And see the output below :

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