math question

[nitrolic2]

hey u guys i need a code for the following :

Some one writes a + or - or * or / into a text box there are

4 such text boxes and in between of those numbers like: (the [ ] stand for a text box):

example:
[ 2 ] [ - ] [ 3 ] [ + ] [ 5 ][ / ] [ 1 ]

now how do i get the computer to solve that?

im sure its easy cause i think i have done it before i just cant remember it now, thanks a lot

I hope i didn't make it confusing

[pro2]

I'm not sure If I understand:
[ 2 ] [ - ] [ 3 ] [ + ] [ 5 ][ / ] [ 1 ]

TOTAL= val(text1.text) - val(text2.text) _
+ val(text3.text) / val(text4.text)


is it what you want ?

[sanon]

It will be easier if you use textbox array.

Private Sub Command1_Click()
    Dim i As Integer
    Dim var1 As Integer
    Dim var2 As Integer
    
    var1 = CInt(Text1(0))
    For i = 0 To 6
        If Text1(i).Text = "+" Then
            var2 = CInt(Text1(i + 1))
            var1 = var1 + var2
        ElseIf Text1(i).Text = "-" Then
            var2 = CInt(Text1(i + 1))
            var1 = var1 - var2
        ElseIf Text1(i).Text = "*" Then
            var2 = CInt(Text1(i + 1))
            var1 = var1 * var2
        ElseIf Text1(i).Text = "/" Then
            var2 = CInt(Text1(i + 1))
            var1 = var1 / var2
        End If
    Next i
    'Result
    Text2.Text = var1
End Sub

[Edited by sanon on 09-23-2000 at 02:52 AM]

[PaulLewis]

In one of the replies, I note that no account is made for order of operation. Is this a requirement of your final solution?

Regards

If you mean you want a way of solving any simple equation that the user inputs, then there are Fortran-based .dll's around.

[nitrolic2]

No order of operations don't make a diffrence to me That i'll take care of... and yes what i need is for the user to put in numbers like 4 2 3 5 12 (or whatever all go into their own text box) then in between they type in a -,+,*, or /

Ie:
4 + 2 - 3 * 5 - 12

but im not sure what numbers or symbols they will enter... but say they enter: 4 + 2 - 3 * 5 - 12 then I want the computer to solve that but all of that is in its own text box so i can't just type in text1.text + text2.text because what if its not a plus but a minus?

Thanks a lot I hope im not confusing you guys

[nitrolic2]

actually the symbols will be computer generated heres the code i got so far:
<code>
Dim A
Dim B
Dim C
Dim D
Dim E
Dim F
Dim G
Dim H
Dim I
Dim J
Private Sub Getarandom_Number()
'// Picking a Random symbol//////////////////////////////////////////////////
Randomize
retval = Int((4 * Rnd) + 1)
If retval = 1 Then retsign = "+"
If retval = 2 Then retsign = "-"
If retval = 3 Then retsign = "*"
If retval = 4 Then retsign = "/"
Text2.Text = retsign
Randomize
retval = Int((4 * Rnd) + 1)
If retval = 1 Then retsign = "+"
If retval = 2 Then retsign = "-"
If retval = 3 Then retsign = "*"
If retval = 4 Then retsign = "/"
Text4.Text = retsign
Randomize
retval = Int((4 * Rnd) + 1)
If retval = 1 Then retsign = "+"
If retval = 2 Then retsign = "-"
If retval = 3 Then retsign = "*"
If retval = 4 Then retsign = "/"
Text6.Text = retsign
Randomize
retval = Int((4 * Rnd) + 1)
If retval = 1 Then retsign = "+"
If retval = 2 Then retsign = "-"
If retval = 3 Then retsign = "*"
If retval = 4 Then retsign = "/"
Text8.Text = retsign
'//end picking a random symbol////////////////////////////////////////////////
End Sub

Private Sub Cmdok_Click()
Getarandom_Number
Attemptto_Solve
End Sub

Private Sub Attemptto_Solve()
'Try and solve given the current numbers and symbols
A = Text1.Text
B = Text2.Text
C = Text3.Text
D = Text4.Text
E = Text5.Text
F = Text6.Text
G = Text7.Text
H = Text8.Text
I = Text9.Text
J = Text10.Text

End Sub

You like going the long way around huh nitriolic2?

you should check out SELECT CASE statements and DEFSTR

Dim A
Dim B
Dim C
...

'would be replaced by
Defstr A-J

'or even better, use an array.

'and then ...
If retval = 1 Then retsign = "+" 
If retval = 2 Then retsign = "-" 
If retval = 3 Then retsign = "*" 
If retval = 4 Then retsign = "/" 

'would be replaced by

Select case Retval
case 1
retsign = "+"
case 2
retsign = "-"
case 3
retsign = "*"
case 4
retsign = "/"
end select

and perhaps loop through a control array of textboxes instead of naming them explicitly.

Just an idea.

[kokopeli]

Here is a start(I'll let you type out the rest)

Option Explicit

Dim retval
Dim retsign
Dim A As Integer
Dim B
Dim C As Integer
Dim D
Dim E As Integer
Dim F
Dim G As Integer
Dim H
Dim i As Integer
Dim J
Private Sub Getarandom_Number()
'// Picking a Random symbol/
Dim i As Integer
For i = 0 To 3
Randomize
retval = Int((4 * Rnd) + 1)
If retval = 1 Then retsign = "+"
If retval = 2 Then retsign = "-"
If retval = 3 Then retsign = "*"
If retval = 4 Then retsign = "/"
Text2(i).Text = retsign
Next i

End Sub


Private Sub Load_Values()

A = Val(Text1(0).Text)
B = Text2(0).Text
C = Val(Text1(1).Text)
D = Text2(1).Text
E = Val(Text1(2).Text)
F = Text2(2).Text
G = Val(Text1(3).Text)
H = Text2(3).Text
i = Val(Text1(4).Text)
End Sub

Private Sub Command1_Click()
Getarandom_Number
Load_Values
End Sub

Private Sub Command2_Click()

     Dim var1 As Integer
     var1 = A
        If B = "+" Then
            var1 = var1 + C
        ElseIf B = "-" Then
            var1 = var1 - C
        ElseIf B = "*" Then
            
            var1 = var1 * C
        ElseIf B = "/" Then
            
            var1 = var1 / C
        End If
    Text3.Text = var1

  'just keep going
    
End Sub

Put your numbers in textbox array Text1(0 to 4) and operators in textbox array Text2(0 to 3). answer is text 3. To test it make sure the Text(0)is a higher number than Text(1) in case of division. This will only do the first equation. Repeat this with Var2 and so on then add var1, var2 etc. for the answer.

[Peterson]

What you want to do is called symolic programming. Do a search at zdnet.com or northernlight.com using the search terms:

visual basic symbolic (or)
visual basic equation symbolic

hope this helps.

-lp

[HarryW]

Well personally, I would do this as one text string (I'd get the input and concatenate it to one expression or just ask for input like "1+3-7/4", spaces don't matter) and I'd use a stack system.

Parse the expression string and split it into terms by the * and / operators, then split the terms into sub-terms by the + and - operators. That would be done by functions that analyse substring expressions that are passed to them. When you have the subterms you apply the + and - operators to them with an add/subtract function, and when values for those functions are returned you apply the * and / operators to them with a multiply/divide function.

Well that's how I'd do it anyway

[PaulLewis]

When you have the subterms you apply the + and - operators to them with an add/subtract function, and when values for those functions are returned you apply the * and / operators to them with a multiply/divide function.

I think you mean that you would do the / and * first, then once those have returned, do the + and -? The way you wrote it, it seems like you'd propose doing it backwards

But in case I read your suggestion backwards, I can tell you now that I agree with your general approach. I made the same sort of thing into a set of Java Classes for a project I worked on. When you start allowing user defined functions and brackets (not to mention exponents), life gets interesting

Cheers

[HarryW]

You're right, I think I got it backwards, thank you for pointing that out

Brackets are pretty easy to add, you just treat each bracketed expression as an individual expression and call your main evaluation function again, ie use recursion. I can imagine that user-defined functions and exponents make things interesting though Any idea how to do square roots?

[parksie]

For a square root, how about something like:

(number)^0.5

...that way you can use everything else in the normal way.