pass variable value in function loop vb.net

Question

The function getQuiz() accepts 2 parameters the line number and the path of a csv file. It splits out thhe question and options then checks against the correct answer which works fine. I want to be able to return the score at the end of the quiz. The problem lies with fact I'm looping through the function. The score resets each time.

How can I retrieve the score at the end of the quiz? This is how the function is being called:

'Calls the getQuiz function
Sub Main()
    Dim i As Integer

    For i = 2 To 6
        getQuiz(i, "C:\Users\HisEasy.csv")   
    Next

End Sub


Function getQuiz(ByVal lineNumber As Integer, ByVal filename As String) As String
    Dim allLines As List(Of String) = New List(Of String)
    Dim qQuest, qOption1, qOption2, qOption3, answer
    Dim quizVar

    Dim n As Long
    Dim score As long
    score = 0
    Using reader As New System.IO.StreamReader(filename)
        For i As Integer = 1 To lineNumber - 1
            If reader.ReadLine() Is Nothing Then
                Throw New ArgumentOutOfRangeException("lineNumber")
            End If
        Next
        ' Attempts to read the line you've requested '
        Dim line As String = reader.ReadLine()
        If line Is Nothing Then
            Throw New ArgumentOutOfRangeException("lineNumber")
        End If

        line = Replace(line, Chr(34), "")
        quizVar = Split(line, ",")

        qQuest = quizVar(1)
        qOption1 = quizVar(2)
        qOption2 = quizVar(3)
        qOption3 = quizVar(4)

        Console.WriteLine(qQuest)
        Console.WriteLine(qOption1)
        Console.WriteLine(qOption2)

        answer = Console.ReadLine()
        If answer = qOption3 Then
            Console.WriteLine("Correct Answer!")
            Console.ReadLine()
            score = n + 1
            Return score
        End If

    End Using

End Function

You could add up the score in the Main part. Simply return 0 or 1 as appropriate from the getQuiz function. Also, you may be interested in the File.ReadAllLines Method which reads all the lines from a file into an array in one go, so you wouldn't have to keep reading the file for every question. — Andrew Morton
– Andrew Morton, Commented Nov 20, 2017 at 9:07
Isn't the obvious thing to simply move the declaration of the score variable outside the getQuiz method? — jmcilhinney
– jmcilhinney, Commented Nov 20, 2017 at 9:11

FadedToObscurity · Accepted Answer · 2017-11-20 10:45:32Z

You could use the return value of your function getQuiz(), which you are doing nothing with at the moment

'Calls the getQuiz function
Sub Main()
    Dim i As Integer
    Dim score as Integer

    For i = 2 To 6
        If getQuiz(i, "C:\Users\HisEasy.csv") = True then
            score += 1
        End If
    Next

End Sub


Function getQuiz(ByVal lineNumber As Integer, ByVal filename As String) As Boolean
    Dim allLines As List(Of String) = New List(Of String)
    Dim qQuest, qOption1, qOption2, qOption3, answer
    Dim quizVar

    Dim n As Long
    Dim score As long

    Using reader As New System.IO.StreamReader(filename)
        For i As Integer = 1 To lineNumber - 1
            If reader.ReadLine() Is Nothing Then
                Throw New ArgumentOutOfRangeException("lineNumber")
            End If
        Next
        ' Attempts to read the line you've requested '
        Dim line As String = reader.ReadLine()
        If line Is Nothing Then
            Throw New ArgumentOutOfRangeException("lineNumber")
        End If

        line = Replace(line, Chr(34), "")
        quizVar = Split(line, ",")

        qQuest = quizVar(1)
        qOption1 = quizVar(2)
        qOption2 = quizVar(3)
        qOption3 = quizVar(4)

        Console.WriteLine(qQuest)
        Console.WriteLine(qOption1)
        Console.WriteLine(qOption2)

        answer = Console.ReadLine()
        If answer = qOption3 Then
            Console.WriteLine("Correct Answer!")
            Console.ReadLine()
            Return True
        End If

    End Using

End Function

Also you should really consider Andrew Morton's comment regarding the workflow of your application, since loading the entire quiz content every time getQuiz is called is pretty redundant here.

Detonar · Accepted Answer · 2017-11-20 12:14:21Z

Why not just

'Calls the getQuiz function
Sub Main()
    Dim i As Integer
    Dim score as long

    score = 0

    For i = 2 To 6
        'Add score after each call
        score = score + getQuiz(i, "C:\Users\HisEasy.csv")   

    Next

End Sub

'Use Long instead of String as return type
Function getQuiz(ByVal lineNumber As Integer, ByVal filename As String) As long
    Dim allLines As List(Of String) = New List(Of String)
    Dim qQuest, qOption1, qOption2, qOption3, answer
    Dim quizVar

    Dim n As Long
    Dim score As long
    score = 0
    Using reader As New System.IO.StreamReader(filename)
        For i As Integer = 1 To lineNumber - 1
            If reader.ReadLine() Is Nothing Then
                Throw New ArgumentOutOfRangeException("lineNumber")
            End If
        Next
        ' Attempts to read the line you've requested '
        Dim line As String = reader.ReadLine()
        If line Is Nothing Then
            Throw New ArgumentOutOfRangeException("lineNumber")
        End If

        line = Replace(line, Chr(34), "")
        quizVar = Split(line, ",")

        qQuest = quizVar(1)
        qOption1 = quizVar(2)
        qOption2 = quizVar(3)
        qOption3 = quizVar(4)

        Console.WriteLine(qQuest)
        Console.WriteLine(qOption1)
        Console.WriteLine(qOption2)

        answer = Console.ReadLine()
        If answer = qOption3 Then
            Console.WriteLine("Correct Answer!")
            Console.ReadLine()
            score = n + 1
            Return score
        End If

    End Using

End Function

Collectives™ on Stack Overflow

pass variable value in function loop vb.net

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related