Getting inputs values to display true or false

Hello I have several text boxes that I will input answers into and I want them to catch the values if they are incorrect or correct.

Example: the user will input a Letter for the answer, A or a, and I was curious to how the correct input can detect if the answer is correct.

If the answer is A B C or D then no message should display but when it's some other value this message will come up.

How do I use true or false in this code?

Code:

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Dim dbl1 As Double
dbl1 = CDbl(txt1.Text)

If dbl1 Not 'A OR a' Then
'Display message
MessageBox.Show("Enter A, B, C, or D")

---

If you use regular expressions, you can get a boolean with isMatch(). In this case it accepts one character, either upper/lowercase of A through D.

Code:

---

Imports System.Text.RegularExpressions

---

Code:

---

        If Regex.IsMatch(TextBox1.Text, "[A-Da-d]") Then
            MessageBox.Show("Match")
        End If

---

However, it may just be easier to convert all texboxes to uppercase and look for the specified answer that way.

Code:

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        Select Case TextBox1.Text.ToUpper
            Case "A"
                'do stuff
            Case "B"
                'etc....
        End Select

---

How come when I do

Code:

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Imports System.Text.RegularExpressions

        If regex.IsMatch(txt1.Text, "[A-D]") Then

---

I get a Syntax error for Imports
and "'IsMatch' is not a member of string"



Im really new to this program and taking an intro course so I barely know basics

put imports outside the class, so at the very top of your code.

Code:

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Imports System.Text.RegularExpressions
Public Class Form1
'the rest of your code
End Class

---

So I have a problem where I am given a list of 20 answers to a quiz. All answers are A-D. The user will input into 20 different text boxes. If the user gets it rights it will add to a total count of 20. If it user enters anything beside A-D then an error message will display. At the end of the program, the number of correct answers will display, and if the user gets 15 or more then a message will display that you have passed the test, if the user gets less then it will display a fail message.


Anyways, not for you to do it. but how do I do an ItemCount for correct answers? Would it be

Code:

---

Dim intCount As Integer


        If str1.IsMatch(txt1.Text, "[A-D]") Then
            intCount += 1

            Select Case txt1.Text.ToUpper
                Case "A"
                Case "B"
                Case "C"
                Case "D"
            End Select

            If Not MessageBox.Show("Enter A,B,C or D") Then

            End If

            'Holds Values
            str1 = CDbl(txt1.Text)
            str2 = CDbl(txt2.Text)
            str3 = CDbl(txt3.Text)
            str4 = CDbl(txt4.Text)
            str5 = CDbl(txt5.Text)
            str6 = CDbl(txt6.Text)
            str7 = CDbl(txt7.Text)
            str8 = CDbl(txt8.Text)
            str9 = CDbl(txt9.Text)
            str10 = CDbl(txt10.Text)
            str11 = CDbl(txt11.Text)
            str12 = CDbl(txt12.Text)
            str13 = CDbl(txt13.Text)
            str14 = CDbl(txt14.Text)
            str15 = CDbl(txt15.Text)
            str16 = CDbl(txt16.Text)
            str17 = CDbl(txt17.Text)
            str18 = CDbl(txt18.Text)
            str19 = CDbl(txt19.Text)
            str20 = CDbl(txt20.Text)

---

You convert txt1.Text to double value and put the result in dbl1 and then you check if it is A or a, how comes?

Try this code instead

vb Code:

Select Case TextBox1.Text.ToUpper
            Case "A", "B", "C", "D"
                ' Check if it is the correct answer
            Case Else
                'Display message
                MessageBox.Show("Enter A, B, C, or D")
        End Select

Edit:
Sorry i replayed without seeing above replay

try this for me:

Code:

---

        Dim score As Integer = 0
        For i As Integer = 1 To 20
            Dim txt As TextBox = DirectCast(Me.Controls("txt" & i), TextBox)
            If Regex.IsMatch(txt.Text, "[A-Da-d]") Then
                score += 1
            End If
        Next
        MessageBox.Show("Score: " & score)

---

Also, as 4x2y mentions, you don't need to use a double when the only thing you're working with is a string.

During my debugging program I get Object Reference not set to an instance of an object

Code:

---

If Regex.IsMatch(txt1.Text, "[A-Da-d]") Then

---

This is what I have so far

Code:

---

Dim score As Integer = 0
        For i As Integer = 1 To 20
            Dim txt1 As TextBox = DirectCast(Me.Controls("B" & i), TextBox)
            If Regex.IsMatch(txt1.Text, "[A-Da-d]") Then
                score += 1
            End If
        Next

        If score >= 15 Then
            MessageBox.Show("You have passed the Test!")
        End If
        If score < 15 Then
            MessageBox.Show("You have failed the Test!")
        End If


        'Holds Values
        str1 = CStr(txt1.Text)
        str2 = CStr(txt2.Text)
        str3 = CStr(txt3.Text)
        str4 = CStr(txt4.Text)
        str5 = CStr(txt5.Text)
        str6 = CStr(txt6.Text)
        str7 = CStr(txt7.Text)
        str8 = CStr(txt8.Text)
        str9 = CStr(txt9.Text)
        str10 = CStr(txt10.Text)
        str11 = CStr(txt11.Text)
        str12 = CStr(txt12.Text)
        str13 = CStr(txt13.Text)
        str14 = CStr(txt14.Text)
        str15 = CStr(txt15.Text)
        str16 = CStr(txt16.Text)
        str17 = CStr(txt17.Text)
        str18 = CStr(txt18.Text)
        str19 = CStr(txt19.Text)
        str20 = CStr(txt20.Text)

---

I know I just have to do the part for all 20 of them but I just am trying to get the first one to work

Code:

---

Dim score As Integer = 0
        For i As Integer = 1 To 20
            Dim txt1 As TextBox = DirectCast(Me.Controls("B" & i), TextBox)
            If Regex.IsMatch(txt1.Text, "[A-Da-d]") Then
                score += 1
            End If
        Next

---

No no no, you changed everything on what I gave you. What the code does is creates an object of TextBox and iterates from the actual TextBoxes called txt1 through txt20. For each textbox, itchecks to see if it matches the letters A through D and if it does, adds 1 to the score.

replace everything you have there with this:

Code:

---

        Dim score As Integer = 0
        For i As Integer = 1 To 20
            Dim txt As TextBox = DirectCast(Me.Controls("txt" & i), TextBox)
            If Regex.IsMatch(txt.Text, "[A-Da-d]") Then
                score += 1
            End If
        Next
        If score >= 15 Then
            MessageBox.Show("You have passed the Test!")
        End If
        If score < 15 Then
            MessageBox.Show("You have failed the Test!")
        End If

---

So now how Do I declare if the Answer for the problem is correct or incorrect?

like

Code:

---

If str1 = "B" Then
score += 1
End If

---

Is that correct?

I would make an array of the correct answers ahead of time, and with an index of the loop (in this case 'i') you could compare the supplied answer to the correct answer.

Code:

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        Dim answers As String() = {"A", "B", "C", "D", "A", "B", "C", "D", "A", "B", "C", "D", "A", "B", "C", "D", "A", "B", "C", "D"}

        Dim score As Integer = 0
        For i As Integer = 1 To 20
            Dim txt As TextBox = DirectCast(Me.Controls("txt" & i), TextBox)
            If Regex.IsMatch(txt.Text, "[A-Da-d]") Then
                If answers(i-1) = txt.Text.ToUpper Then score += 1
            End If
        Next
        If score >= 15 Then
            MessageBox.Show("You have passed the Test!")
        End If
        If score < 15 Then
            MessageBox.Show("You have failed the Test!")
        End If

---

I'm not quite sure how to correspond the array string to the index number

Would it be like this?

Code:

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Dim strAnswers() As String = {"B", "D", "A", "A", "C", "A", "B", "A", "C", "D", "B", "C", "D", "A", "D", "C", "C", "B", "D", "A"}
        Dim score As Integer = 0
        For i As Integer = 1 To 20


            Dim txt As TextBox = DirectCast(Me.Controls("txt" & i), TextBox)
            If Regex.IsMatch(txt.Text, "[A-Da-d]") Then
                score += 1
            End If
        Next

---

Or more like this

Code:

---

strAnswers(0) = "B"

---

The first part, yes. I edited my last post, let me know if that works for you.

how would I declare the array to that specific answer. for example, like answer 20 to what they put in.

Code:

---

For str1 = strAnswers(0) Then
score += 1
Next

---

Read post 14, then look at the code in post 12.

I'm really confused at what I should be doing next now. I get a running error when I run the program. If you could take a quick look. I'm stumped

Some questions on your setup
Is it correct that all entries like A,B,C or D (upper or lower case) are correct and make an increase in the overall result?
Shouldn't it be like A,B,c or D are usable answers, however only one of them will result in an increase of score?

I believe with this statement, it includes the lowercase as well. It just turns it into an uppercase.

Code:

---

Select Case txt1.Text.ToUpper
 If answers(i - 1) = txt.Text.ToUpper Then score += 1

            Case "A", "B", "C", "D"
                ' Check if it is the correct answer
            Case Else
                'Display message
                MessageBox.Show("Enter A, B, C, or D")
        End Select

---

The one thing I can't seem to understand is the running error I get

Code:

---

If Regex.IsMatch(txt.Text, "[A-Da-d]") Then

---

Okay, I found the issue with the code you currently uploaded. You had your textboxes within a GroupBox, so the "Me.Controls" portion wouldn't work and would cause an error. I replaced it with "GroupBox1.Controls" and am having it work correctly. Also I cleaned up a little of the code.

Code:

---

Imports System.Text.RegularExpressions

Public Class Form1

    Private Sub btnExit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnExit.Click
        Me.Close()
    End Sub

    Private Sub btnClear_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnClear.Click
        For i As Integer = 1 To 20
            DirectCast(GroupBox1.Controls("txt" & i), TextBox).Clear()
        Next
    End Sub

    Private Sub btnScore_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnScore.Click

        Dim answers As String() = {"A", "B", "C", "D", "A", "B", "C", "D", "A", "B", "C", "D", "A", "B", "C", "D", "A", "B", "C", "D"}

        Dim score As Integer = 0
        For i As Integer = 1 To 20
            Dim txt As TextBox = DirectCast(GroupBox1.Controls("txt" & i), TextBox)

            If Regex.IsMatch(txt.Text, "[A-Da-d]") Then
                If answers(i - 1) = txt.Text.ToUpper Then score += 1
            End If
        Next
        If score >= 15 Then
            MessageBox.Show("You have passed the Test!")
        End If
        If score < 15 Then
            MessageBox.Show("You have failed the Test!")
        End If

    End Sub
End Class

---

How come when I put random answers that equal less then 15 I get this running error

"Object Reference not set to an instance of an object"

Code:

---

If score < 15 Then
            MessageBox.Show("You have failed the Test!")
        End If

---

Even when I put all the right answers It still displays that I have failed the test?

With what I have above, i can put any alphanumeric key and even symbols with no error. So it leads me to believe that you may have changed the code? What are you putting in that is random?

Well look at post #22, for some reason nothing is making me pass the test?

I did. And with the code in post 20 exactly as it is shown there, and typing the answer from the code into the boxes, it passes just fine. Are you SURE you didn't change the code again like you did before?

This is what I have in total. I need the answer form for later but as of right now. it just fails me with my inputs

Okay, you're clearly not listening when I mentioned to replace all of the code.
Here it is again...

Code:

---

Imports System.Text.RegularExpressions
Public Class Form1
    Private Sub btnExit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnExit.Click
        Me.Close()
    End Sub

    Private Sub btnClear_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnClear.Click
        For i As Integer = 1 To 20
            DirectCast(GroupBox1.Controls("txt" & i), TextBox).Clear()
        Next
    End Sub

    Private Sub btnScore_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnScore.Click
        Dim answers As String() = {"A", "B", "C", "D", "A", "B", "C", "D", "A", "B", "C", "D", "A", "B", "C", "D", "A", "B", "C", "D"}
        Dim score As Integer = 0
        For i As Integer = 1 To 20
            Dim txt As TextBox = DirectCast(GroupBox1.Controls("txt" & i), TextBox)
            Dim lbl As Label = DirectCast(AnswerForm.GroupBox1.Controls("label" & i), Label)
            lbl.Text = i & ": " & DirectCast(GroupBox1.Controls("txt" & i), TextBox).Text
            If Regex.IsMatch(txt.Text, "[A-Da-d]") Then
                If answers(i - 1) = txt.Text.ToUpper Then
                    score += 1
                Else
                    lbl.ForeColor = Color.Red
                End If
            End If
        Next
        If score >= 15 Then
            MessageBox.Show("You have passed the Test!")
        End If
        If score < 15 Then
            MessageBox.Show("You have failed the Test!")
        End If
        AnswerForm.Show()
    End Sub
End Class

---

EDIT: I noticed what you were also trying to do with the second form and added a loop at the end to make those changes as well. Of course the ordering of those labels are in the wrong location on the form though.
EDIT2: Condensed code.

Ok this is my final product and I am not getting any pass on this test at all. I'm not sure if it is my program that I was I constantly opening other projects but I still get the same results of failure

Try this...

I see why I keep getting fail. Everything is mixed up. Why is this?

http://i.imgur.com/at0Ng.jpg

Update the answers array on the button click to the answers you want. I would have figured you knew the answers you wanted.

Wow, my answers got switched around a little bit. Thank you so much for everything.

For everyone else that reads this. It's really the little errors that screw over your whole program. +1 skor13


One more thing. How can I make sure that the only values that are entered are only A, B, C, or D?


I tried this but it seems to fail

Code:

---

Select Case txt1.Text.ToUpper
                Case "A", "B", "C", "D"
                    ' Check if it is the correct answer
                Case Else
                    'Display message
                    MessageBox.Show("Enter A, B, C, or D")
            End Select

---

Add this Sub to the code and remove what you just posted entirely.

Code:

---

    Private Sub txt1_KeyDown(ByVal sender As System.Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles txt9.KeyDown, txt8.KeyDown, txt7.KeyDown, txt6.KeyDown, txt5.KeyDown, txt4.KeyDown, txt3.KeyDown, txt20.KeyDown, txt2.KeyDown, txt19.KeyDown, txt18.KeyDown, txt17.KeyDown, txt16.KeyDown, txt15.KeyDown, txt14.KeyDown, txt13.KeyDown, txt12.KeyDown, txt11.KeyDown, txt10.KeyDown, txt1.KeyDown
        If Not (e.KeyCode = Keys.A Or Keys.B Or Keys.C Or Keys.D) Then
            e.SuppressKeyPress = True
        End If
    End Sub

---

Weird, restricting keys from being pressed. For some reason it will only let me press A and not B, C, or D

ahh shoot, sorry, change that line to

Code:

---

If Not (e.KeyCode = Keys.A) And Not (e.KeyCode = Keys.B) And Not (e.KeyCode = Keys.C) And Not (e.KeyCode = Keys.D) Then

---

Thanks! You've taught me a lot. Couldn't have done it without you

one last bit, you may want to add this to the if statement so they can delete what they wrote.

Code:

---

And Not (e.KeyCode = Keys.Back)

---

users can still type more than one character, but you can limit that by setting the length of the textboxes.