I am making a quiz for my computer science class and the basic concept is that you have 15 keywords and 15 definitions. All need to be randomly displayed and the correct answer has to appear. The user has to match the correct definition to the keyword twice and then that keyword and definition are not displayed again. When all have been answered twice the quiz is over.
I have stored both my keywords and my definitions in the same file so they don't get out of sync. The text file looks like so:
Keyword1,Definition1
Keyword2,Definition2
Keyword3,Definition3
Keyword4,Definition4
etc (15 lines in total)
Currently I have my dictionary manually created like so:
Const NUMBER_OF_ANSWERS As Integer = 3
Public Class Form1
Dim kv As New Dictionary(Of String, String)
kv.Add("Keyword1", "Definition1")
kv.Add("Keyword2", "Definition2")
kv.Add("Keyword3", "Definition3")
kv.Add("Keyword4", "Definition4")
kv.Add("Keyword5", "Definition5")
kv.Add("Keyword6", "Definition6")
kv.Add("Keyword7", "Definition7")
kv.Add("Keyword8", "Definition8")
kv.Add("Keyword9", "Definition9")
kv.Add("Keyword10", "Definition10")
kv.Add("Keyword11", "Definition11")
kv.Add("Keyword12", "Definition12")
kv.Add("Keyword13", "Definition13")
kv.Add("Keyword14", "Definition14")
kv.Add("Keyword15", "Definition15")
Dim r As New Random
Dim kvRandom As List(Of KeyValuePair(Of String, String)) =
kv.OrderBy(Function() r.Next).ToList
'questions will appear in random order
For Each line As KeyValuePair(Of String, String) In kvRandom
Dim keyword As String = line.Key
Dim correctDefinition As String = line.Value
Dim keywords As New List(Of String)
keywords.Add(keyword)
keywords.AddRange(kv.Keys.Except({keyword}).
OrderBy(Function() r.Next).Take(NUMBER_OF_ANSWERS - 1))
Dim definitionsRandom As List(Of String) =
keywords.Select(Function(x) kv(x)).OrderBy(Function() r.Next).ToList
'TODO: need to write some code here
'display keyword and three possible definitions to the user
'(out of which one is correct)
'answers will also appear in random order
'Check answer against value stored in "correctDefinition"
LabelKeyword.Text = keyword
RadioButtonDef1.Text = definitionsRandom(0)
RadioButtonDef2.Text = definitionsRandom(1)
RadioButtonDef3.Text = definitionsRandom(2)
Next
End Sub
I know that to populate a dictionary from a textfile I do the following:
For Each line As String In IO.File.ReadAllLines("keywords_and_definitions.txt")
Dim parts() As String = line.Split(",")
kv.Add(parts(0), parts(1))
Next
However I am not sure how to change this code to successfully implement this. Thanks to previous help here I was told to do this (by #Neolisk):
set your progress variable to 0 of 14 (number of questions minus 1, indexes are zero based in VB.NET). At first question, display question #0, when user presses Next, increment progress variable. Don't forget to count valid/invalid answers. You may want to store full answer history for a user. If you need mode detail on this one, I think it's worth asking a separate question - provide the functionality you need there.
Again I am not sure how to go about doing this. The above code works wonders it's just I'm not sure how to change the code to populate the dictionary from the text file rather than how I have done it above as it is a requirement that we include our keywords and definitions from a text file.
Maybe I'm not understanding your question, but just mixing the two together should do the trick, no??
Const NUMBER_OF_ANSWERS As Integer = 3
Public Class Form1
Dim kv As New Dictionary(Of String, String)
For Each line As String In IO.File.ReadAllLines("keywords_and_definitions.txt")
Dim parts() As String = line.Split(",")
kv.Add(parts(0), parts(1))
Next
Dim r As New Random
...
Or am I not understanding your question?
Also, I'll give you the hint, since this is homework, that the Dim parts() As String could be moved outside of your loop.
Hopw this is what you were asking and it helps set you in the right direction
Related
I'm using Visual studio to build a small utility.
I'm importing variables from a text file (this makes my program expandable in the future).
I'm running into a road block trying to split the variables into usable parts.
The text file is set up as such:
Game1:flshflhdlsfsdsfs
Game2:ugdjgndrgbdvdnjd
Game3:gnnereknengievke
And the code I've gathered from searching around trying to understand how I could do this is (It's gone through multiple rewrites but I feel this is probably the closest I've gotten):
Dim value As String = File.ReadAllText("Games.txt")
Dim cut_at As String = ":"
Dim x As Integer = InStr(value, cut_at)
Dim string_before As String = value.Substring(0, x - 2)
Dim string_after As String = value.Substring(x + cut_at.Length - 1)
Games_drp.Items.AddRange(string_before)
When I run a test like this, I get an error that String_before cannot be converted to an object. I tried switching "Dim string_before As String = value.Substring(0, x - 2)" to Dim string_before As Object = value.Substring(0, x - 2), but the dropdown that's supposed to be populated by at least one of the entries before the : has absolutely nothing in it.
Being pretty new at VB and feeling like I've exhausted pretty much every way I could think of searching in google and trying to piece together various bits of information, I figure I'd try asking my own direct question:
How would I go about reading all the lines from a text file, then splitting before the : to fill a combobox, and using a label to display the string after the : matching which ever entry is selected in the dropdown.
Thanks in advance for any help.
EDIT with full code:
Imports System.IO
Public Class Saves_frm
Private Sub Saves_frm_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim value As String = File.ReadAllText("Games.txt")
Dim cut_at As String = ":"
Dim x As Integer = InStr(value, cut_at)
Dim string_before As String = value.Substring(0, x - 2)
Dim string_after As String = value.Substring(x + cut_at.Length - 1)
Games_drp.Items.AddRange(string_before)
End Sub
End Class
When run as is, I get an error that 'string_before' can't be converted from a string to an object, but when I make the following change from:
Dim string_before As String = value.Substring(0, x - 2)
to:
Dim string_before As Object = value.Substring(0, x - 2)
The error goes away, but the dropdown remains blank.
It's easier to use File.ReadAllLines, as it returns an array with all the file's lines. Then, you can loop through the lines, splitting each line and adding the result to the ListBox. This should be an example, but feel free to correct any mistakes I made, as I wrote it on my phone and it's been a long time since I used VB.
Dim lines() As String = File.ReadAllLines("file.txt")
For Each line As String In lines
Dim split() As String = line.Split(":"c)
gDic.Add(split(0), split(1))
Next
EDIT: Then, you most certainly want a dictionary that contains the name and the data, check the updated code.
Then, add the names by looping through gDic.Keys. When a name is selected, access its value with gDic("key").
Needed code is something like this:
Dim myArray(0) As String
Dim ay As String = "ay"
myArr & ay(0) = "asd"
I've tried but did not worked
Dim classlist1(0) As String
Dim classlist2(0) As String
Dim classlist3(0) As String
Dim classlist4(0) As String
Dim count As Integer = 0
For _year As Integer = 1 To 4
("classlist" & _year)(count) = "hi"
count += 1
Next
Any time you see something like this:
Dim classlist1(0) As String
Dim classlist2(0) As String
Dim classlist3(0) As String
' etc.
It's an indication that you're using the wrong data structure. Instead of trying to dynamically build variable names (which isn't really possible in a static language, at least not without some really ugly reflection code with a high potential for runtime errors), just use a collection.
For example, if you want a collection of strings:
Dim classList As New List(Of String)()
And if you want a collection of collections of strings:
Dim classLists As New List(Of List(Of String))()
Then you can reference the nested lists within the parent list. So to add your first "year" of classes:
classLists.Add(new List(Of String))
And add a class to that year:
classLists(0).Add("some value")
As you can see, it starts to get a little difficult to keep track of the data structures. This is where creating custom types and structures becomes very useful. For example, rather than representing a "year" as a list of strings, create an actual Year class. That class can internally hold a list of strings, and other logic/data.
Try Dictionary<TKey, TValue> Class From MSDN.
Dim classLists As New Dictionary(Of String, String)()
'Add items with keys
For _year As Integer = 1 To 4
classLists.Add(String.Format("classlist{0}",_year), "hi")
Next
And you can get value by key later
Dim key As String = "classlist2"
Dim value As String = classLists(key)
I am making a quiz for my computer science class and the basic concept is that you have 15 keywords and 15 definitions. All need to be randomly displayed and the correct answer has to appear. The user has to match the correct definition to the keyword twice and then that keyword and definition are not displayed again. When all have been answered twice the quiz is over.
I have stored both my keywords and my definitions in the same file so they don't get out of sync. The text file looks like so:
Keyword1 = Definition1
Keyword2 = Definition2
Keyword3 = Definition3
etc (Total of 15)
My main form looks like this:
Public Class quiz
Private Sub quiz_load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles myBase.Load
Dim MyList As List(Of KeyValuePair(Of String, String)) = New List(Of String, String))
For Each line As String In System.IO.File.ReadAllLines("my-file-path")
Dim Pair() As String = line.split("=")
mylist.add(New KeyValuePair(Of String, String)(Pair(0), Pair(1)))
Next
I am displaying the random keyword in a label and the definitions in radiobuttons. Two need to be random definitions and one has to be the correct definition to the keyword shown, which also needs to be displayed randomly.
What I am asking is:
How do I finish this list off as it is overwriting the other 15 lines only using the last one?
How can I randomize the list of keywords and definitions for when they are displayed?
How can I remove the items when each keyword has been matched to its definition twice? E.G: Keyword 1 and definition 1 have been answered correctly twice so remove from list so it won't be displayed again.
This should give you an idea:
Const NUMBER_OF_ANSWERS As Integer = 3
Dim kv As New Dictionary(Of String, String)
kv.Add("Keyword1", "Definition1")
kv.Add("Keyword2", "Definition2")
kv.Add("Keyword3", "Definition3")
Dim r As New Random
Dim kvRandom As List(Of KeyValuePair(Of String, String)) =
kv.OrderBy(Function() r.Next).ToList
'questions will appear in random order
For Each line As KeyValuePair(Of String, String) In kvRandom
Dim keyword As String = line.Key
Dim correctDefinition As String = line.Value
Dim keywords As New List(Of String)
keywords.Add(keyword)
keywords.AddRange(kv.Keys.Except({keyword}).
OrderBy(Function() r.Next).Take(NUMBER_OF_ANSWERS - 1))
Dim definitionsRandom As List(Of String) =
keywords.Select(Function(x) kv(x)).OrderBy(Function() r.Next).ToList
'TODO: need to write some code here
'display keyword and three possible definitions to the user
'(out of which one is correct)
'answers will also appear in random order
'Check answer against value stored in "correctDefinition"
Next
The code is pretty much self-explanatory, if you have any questions, please let me know in comments.
EDIT: Here is how you can populate your dictionary from a file.
'assuming file structure is like this:
'keyword1,definition1
'keyword2,definition2
'keyword3,definition3
'...
For Each line As String In IO.File.ReadAllLines("keywords_and_definitions.txt")
Dim parts() As String = line.Split(",")
kv.Add(parts(0), parts(1))
Next
After you figure out your loading issues, you can follow this basic algorithm to do the rest of your tasks. I don't want to give you exact code for a class assignment. Figuring that kind of thing out is half the fun of learning programming.
Loop through each of the questions, keeping an index to the current
question.
Declare a new list of answers and place the correct answer
from the current question in to the list.
Pick 3 more answers
randomly that are NOT the correct answer, and answers than have been
picked for this question and add them to the answer list.
Randomize the answer list.
Display the questions and answers
Check the chosen answer against the answer for the current question.
Repeat for every question.
I am making a quiz for my computer science class and the basic concept is that you have 15 keywords and 15 definitions. All need to be randomly displayed and the correct answer has to appear. The user has to match the correct definition to the keyword twice and then that keyword and definition are not displayed again. When all have been answered twice the quiz is over.
I have stored both my keywords and my definitions in the same file so they don't get out of sync. The text file looks like so:
Keyword1,Definition1
Keyword2,Definition2
Keyword3,Definition3
...
Thanks to the help from others here on StackOverflow I have managed to get the randomizing and dictionary completed. For reference that looks like this:
Public Class Form1
Private kv As Dictionary(Of String, Answer) 'Define kv as a dictionary
Private keyword As String
Private correctDefinition As String
Const NUMBER_OF_ANSWERS As Integer = 3 'Define the constant NUMBER_OF_ANSWERS
Private Sub RandomiseAnswers()
Dim r As New Random
Dim kvRandom As List(Of KeyValuePair(Of String, Answer)) =
kv.OrderBy(Function() r.Next).ToList
'questions will appear in random order
For Each line As KeyValuePair(Of String, Answer) In kvRandom
Dim keyword As String = line.Key
Dim correctDefinition As String = line.Value.Answer
Dim keywords As New List(Of String)
keywords.Add(keyword)
keywords.AddRange(kv.Keys.Except({keyword}).
OrderBy(Function() r.Next).Take(NUMBER_OF_ANSWERS - 1))
Dim definitionsRandom As List(Of String) =
keywords.Select(Function(x) kv(x).Answer).OrderBy(Function() r.Next).ToList
LabelKeyword.Text = keyword
RadioButtonDef1.Text = definitionsRandom(0)
RadioButtonDef2.Text = definitionsRandom(1)
RadioButtonDef3.Text = definitionsRandom(2)
Next
End Sub
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
'The text file is structured like so:
'Keyword1,Definition1
'Keyword2,Definition2
'Keyword3,Defintion3
'...
'This makes sure that the keywords and the definitions do not get out of sync when randomising, as a dictionary is a key-value data structure. Call the key, get the right value etc.
kv = New Dictionary(Of String, Answer) 'kv = a new dictionary
For Each line As String In IO.File.ReadAllLines("C:\Users\Matt\Documents\keywords.txt") 'Foreach loop populating the dictionary from the text file
Dim parts() As String = line.Split(",") 'Split the Keywords from the definitions where the , is
kv.Add(parts(0), New Answer With {.Answer = parts(1), .Answered = False}) 'Add the two parts (Keyword and Definition) to the Parts with the Answer class
Next
Dim r As New Random 'Define r as new random
Dim kvRandom As List(Of KeyValuePair(Of String, String)) =
kv.OrderBy(Function() r.Next) _
.Select(Function(x) New KeyValuePair(Of String, String)(x.Key, x.Value.Answer)) _
.ToList() 'A Select method to convert the items in the list properly
'questions will appear in random order
For Each line As KeyValuePair(Of String, String) In kvRandom
Dim keyword As String = line.Key
Dim correctDefinition As String = line.Value 'Checks that the correct definition will be displayed when its keyword is randomly displayed.
'Define keywords as a new list
Dim keywords As New List(Of String)
keywords.Add(keyword) 'Adds the keyword to the list as the Part(0) from the text file in the first loop
keywords.AddRange(kv.Keys.Except({keyword}).
OrderBy(Function() r.Next).Take(NUMBER_OF_ANSWERS - 1))
Dim definitionsRandom As List(Of String) =
keywords.Select(Function(x) kv(x).Answer).OrderBy(Function() r.Next).ToList 'Define definitionsRandom as a list. Checks against correctDefinition to know to always display the correct answer as one of the
'random definitions
LabelKeyword.Text = keyword 'Randomly display a keyword
RadioButtonDef1.Text = definitionsRandom(0) 'Randomly display a definition. Checks against correctDefinition to see make sure one definition is always the right answer.
RadioButtonDef2.Text = definitionsRandom(1) 'Randomly display a definition. Checks against correctDefinition to see make sure one definition is always the right answer.
RadioButtonDef3.Text = definitionsRandom(2) 'Randomly display a definition. Checks against correctDefinition to see make sure one definition is always the right answer.
Next
End Sub
Private Sub ButtonNext_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ButtonNext.Click
'If (RadioButtonDef1.Checked And RadioButtonDef1.Text = correctDefinition) Or (RadioButtonDef2.Checked And RadioButtonDef2.Text = correctDefinition) Or (RadioButtonDef3.Checked And RadioButtonDef3.Text = correctDefinition) Then
' If kv(keyword).Answered Then
' kv.Remove(keyword)
' Else
' kv(keyword).Answered = True
' End If
'Else
' MsgBox("Incorrect Answer!")
'End If
If (RadioButtonDef1.Checked And RadioButtonDef1.Text = correctDefinition) Or (RadioButtonDef2.Checked And RadioButtonDef2.Text = correctDefinition) Or (RadioButtonDef3.Checked And RadioButtonDef3.Text = correctDefinition) Then
MsgBox("Correct Answer")
Else
MsgBox("Incorrect Answer. The correct answer is: " & correctDefinition)
End If
End Sub
End Class
I use a subroutine in my buttonNext_click to prevent duplicate code, as you can see above Private Sub RandomiseAnswers().
my issue however is when I come down to the If/else statement where I determine whether the user has selected the correct answer. As you can see I have commented out the original line as I found that it didn't work, and therefore I created one which would display a message box. By using that If/Else statement I have found that it always displays the Incorrect Answer message box and it doesn't display the correct definition.
What is puzzling me the most is that I know that correctDefinition works as it will always display the correct definition to the current keyword however I cannot seem to fathom out how to make it work in the conditional/s.
Does anyone have a possible solution as to why it doesn't seem to like being used in the If/Else statement/s but does work when randomising.
Sorry if it is hard to understand what I am asking.
Any help is much appreciated.
EDITS
code relevant to the Answer class
Public Class Answer
Public Answer As String
Public Answered As Boolean
End Class
You declare correctDefinition twice in your code. Declare it once or better yet make correctDefinition an array eg.
Private correctDefinition() String = New String() { "Definition 1", "Definition 2", "Definition 3" }
I Have a text file that is like the following:
[group1]
value1
value2
value3
[group2]
value1
value2
[group3]
value3
value 4
etc
What I want to be able to do, is load the values into an array (or list?) based on a passed in group value. eg. If i pass in "group2", then it would return a list of "value1" and "value2".
Also these values don't change that often (maybe every 6 months or so), so is there a better way to store them instead of a plain old text file so that it makes it faster to load etc?
Thanks for your help.
Leddo
This is a home work question?
Use the StreamReader class to read the file (you will need to probably use .EndOfStream and ReadLine()) and use the String class for the string manipulation (probably .StartsWith(), .Substring() and .Split().
As for the better way to store them "IT DEPENDS". How many groups will you have, how many values will there be, how often is the data accessed, etc. It's possible that the original wording of the question will give us a better clue about what they were after hear.
Addition:
So, assuming this program/service is up and running all day, and that the file isn't very large, then you probably want to read the file just once into a Dictionary(of String, List(of String)). The ContainsKey method of this will determine if a group exists.
Function GetValueSet(ByVal filename As String) As Dictionary(Of String, List(Of String))
Dim valueSet = New Dictionary(Of String, List(Of String))()
Dim lines = System.IO.File.ReadAllLines(filename)
Dim header As String
Dim values As List(Of String) = Nothing
For Each line As String In lines
If line.StartsWith("[") Then
If Not values Is Nothing Then
valueSet.add(header, values)
End If
header = GetHeader(line)
values = New List(Of String)()
ElseIf Not values Is Nothing Then
Dim value As String = line.Trim()
If value <> "" Then
values.Add(value)
End If
End If
Next
If Not values Is Nothing Then
valueSet.add(header, values)
End If
Return valueSet
End Function
Function GetHeader(ByVal line As String)
Dim index As Integer = line.IndexOf("]")
Return line.Substring(1, index - 1)
End Function
Addition:
Now if your running a multi-threaded solution (that includes all ASP.Net solutions) then you either want to make sure you do this at the application start up (for ASP.Net that's in Global.asax, I think it's ApplicationStart or OnStart or something), or you will need locking. WinForms and Services are by default not multi-threaded.
Also, if the file changes you need to restart the app/service/web-site or you will need to add a file watcher to reload the data (and then multi-threading will need locking because this is not longer confined to application startup).
ok, here is what I edned up coding:
Public Function FillFromFile(ByVal vFileName As String, ByVal vGroupName As String) As List(Of String)
' open the file
' read the entire file into memory
' find the starting group name
Dim blnFoundHeading As Boolean = False
Dim lstValues As New List(Of String)
Dim lines() As String = IO.File.ReadAllLines(vFileName)
For Each line As String In lines
If line.ToLower.Contains("[" & vGroupName.ToLower & "]") Then
' found the heading, now start loading the lines into the list until the next heading
blnFoundHeading = True
ElseIf line.Contains("[") Then
If blnFoundHeading Then
' we are at the end so exit the loop
Exit For
Else
' its another group so keep going
End If
Else
If blnFoundHeading And line.Trim.Length > 0 Then
lstValues.Add(line.Trim)
End If
End If
Next
Return lstValues
End Function
Regarding a possible better way to store the data: you might find XML useful. It is ridiculously easy to read XML data into a DataTable object.
Example:
Dim dtTest As New System.Data.DataTable
dtTest.ReadXml("YourFilePathNameGoesHere.xml")