Converting a Loop projected to an array???

[Jblake00]

Here is the original code.

 Private Sub btnGtGrades_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnGtGrades.Click
       Dim my As IO.StreamReader
       Dim fmtStr As String = "{0,11}{1,4} {2,8}  {3,6}     {4,6}"
       Dim strStudent, Start As String, strLetterGrade As String
       Dim Grade1, Grade2, total As Double
       Dim varEveryonesGrade As Double
       Dim varAverage As Double
       Dim sum As Double
       varAverage = 0
       sum = 0
       If IO.File.Exists("A:\grades.txt") Then
           my = IO.File.OpenText("A:\grades.txt")
           Do While my.Peek <> -1
               Start = my.ReadLine
               strStudent = Start.Substring(0, 11)               
               Grade1 = Start.Substring(12, 4)
               Grade2 = Start.Substring(16, 4)
               varAverage = Math.Round((Grade1 + Grade2) / 2)          
               varEveryonesGrade += varAverage            
               sum += 1
                              Select Case varAverage
                   Case Is >= 90
                       strLetterGrade = "A"
                   Case Is >= 80
                       strLetterGrade = "B"
                   Case Is >= 70
                       strLetterGrade = "C"
                   Case Is >= 60
                       strLetterGrade = "D"
                   Case Is >= 50
                       strLetterGrade = "F"
               End Select
               lstGtGrds.Items.Add(String.Format(fmtStr, strStudent, Grade1, Grade2, varAverage, strLetterGrade))

           Loop
           my.Close()
           varEveryonesGrade = Math.Round(varEveryonesGrade / sum)

           txtDsplyClsAvr.Text = "The class average is " & CStr(varEveryonesGrade)

       Else

           MsgBox("Try putting in the disk that has grades.txt on it!", , "Missing Disk")
       End If
   End Sub

 

I am suposeto be able to easily convert it to an array, but so far it has not been so easy!!

In this project I need to set up a row for the studentd and two columns for the grades'

This is done as

Dim strStudent() As String

and

 Dim grades( ,  ) As Double

Also I need a counter so I done

 Dim Counter As Integer
counter = 0 

Then the rest of the dim statements are as before, here is the rest of my code

If IO.File.Exists("A:\grades.txt") Then
           my = IO.File.OpenText("A:\grades.txt")
           Do While my.Peek <> -1

               Start = my.ReadLine
               counter += 1
           Loop
           my.Close()
           ReDim strStudent(counter)
           my = IO.File.OpenText("A:\grades.txt")
           strStudent(i) = my.ReadLine
           ReDim Grades(counter, 2)


           'strStudent(row) = 1
           '  Start = my.ReadLine

           strStudent(strLetterGrade) = varAverage
           For i = 2 To counter

               If Grades(1, +2) \ 2 = varAverage Then
                   
                   txtDsplyClsAvr.Text = "The class average is " & CStr(varEveryonesGrade)
               End If

               'strStudent = Start.Substring(0, 11)
               ' Grade1 = Start.Substring(12, 4)
               ' Grade2 = Start.Substring(16, 4)
               ' varAverage = Math.Round((Grade1 + Grade2) / 2, 0)
               ' varEveryonesGrade += varAverage
               ' sum += 1

               Select Case varAverage
                   Case Is >= 90
                       strLetterGrade = "A"
                   Case Is >= 80
                       strLetterGrade = "B"
                   Case Is >= 70
                       strLetterGrade = "C"
                   Case Is >= 60
                       strLetterGrade = "D"
                   Case Is >= 50
                       strLetterGrade = "F"
               End Select
               lstGtGrds.Items.Add(String.Format(fmtStr, strStudent, Grades, varAverage, strLetterGrade))

           Next
           my.Close()
           ' varEveryonesGrade = Math.Round(varEveryonesGrade / sum)
      Else
       MsgBox("Try putting in the disk that has grades.txt on it!, , Missing Disk")
       End If

I have gotten some strnge results from this when I get it to out put some thing, it comes out something like string.input 0 0 1 0

But I assume that is because I have got the strings to read, store and divide up the infomation.

Then I need to get the columns to divide with each other because that will be were and what my grades are. When that is done that will give me my average. when I attempt to do this I get an error that tod 89 64 cast to double is invalid.

right know my error has to to with the input box. Something about trying to ad info that is less than my array or trying to divide by zero. not sure which one it was. Maybe aia have had both errors, anyway I will check back in the morning and hopefully I will get some advice that will lead me to a solution.

[Jblake00]

Btw I am sure that yall can tell that I am attemping a nested loop

[Iceplug]

strStudent(strLetterGrade) = varAverage

You probably need to convert this strLetterGrade into a Long, or some type of integer with a Parse method.

But, it doesn't seem like this starts off with anything in it. :confused:

Where are you computing the average?

You can close my after you read that one line from it right before you redim Grades. :)

[PlausiblyDamp]

which line are you getting the error on? It looks like you need to split the line from the file into sperate parts before parsing into a double.

[Jblake00]

I am trying to comput the average with,If Grades(1, +2) \ 2 = varAverage Then...And I beleive the error was here.

 lstGtGrds.Items.Add(String.Format(fmtStr, strStudent, Grades, varAverage, strLetterGrade))

[PlausiblyDamp]

When you are getting the error what is the value of varAverage?

[Jblake00]

Ok lets start over.. Here is my code now.

Dim my As IO.StreamReader
       Dim fmtStr As String = "{0,11}{1,4} {2,8}  {3,6}     {4,6}"
       Dim strStudent() As String
       Dim i As Integer
       Dim row As Double
       Dim Start As String, strLetterGrade As String
       Dim col, Grades(,) As Double
       Dim g1, g2 As Double
       Dim total As Double
       Dim varEveryonesGrade As Double
       Dim varAverage As Double
       ' Dim f As Double
       '  Dim s As Double
       Dim sum As Double
       Dim counter As Integer
       varAverage = 0
       sum = 0
       counter = 0
       
       If IO.File.Exists("A:\grades.txt") Then
           my = IO.File.OpenText("A:\grades.txt")
           Do While my.Peek <> -1
               strStudent(i) = my.ReadLine

               counter += 1
           Loop
           my.Close()
           ReDim strStudent(counter)
           my = IO.File.OpenText("A:\grades.txt")
           strStudent(i) = my.ReadLine
           ReDim Grades(counter, 2)
           strStudent(row) = 1
           Grades(g1, g2) = 2
           g1 = Start.Substring(12, 4)
           g2 = Start.Substring(16, 4)
           varAverage = Grades(g1, +g2) \ 2
           strStudent(strLetterGrade) = varAverage
           For i = 1 To counter

               If Grades(g1, +g2) \ 2 = varAverage Then
                   varEveryonesGrade += varAverage
                   varEveryonesGrade = Math.Round(varEveryonesGrade / sum)


                   txtDsplyClsAvr.Text = "The class average is " & CStr(varEveryonesGrade)
               End If

               sum += 1

               Select Case varAverage
                   Case Is >= 90
                       strLetterGrade = "A"
                   Case Is >= 80
                       strLetterGrade = "B"
                   Case Is >= 70
                       strLetterGrade = "C"
                   Case Is >= 60
                       strLetterGrade = "D"
                   Case Is >= 50
                       strLetterGrade = "F"
               End Select
               lstGtGrds.Items.Add(String.Format(fmtStr, strStudent, g1, g2, varAverage, strLetterGrade))

           Next
           my.Close()
           'varEveryonesGrade = Math.Round(varEveryonesGrade / sum)

       Else

           MsgBox("Try putting in the disk that has grades.txt on it!, , Missing Disk")

       End If

The problem now is I am outofbounds with my array index.

And it has to do with my trying to add g1 and g2. I think.

Any way I got to take a coffee break and think about it.

[PlausiblyDamp]

in the line

Grades(g1, +g2)

could you not just use

Grades(g1, g2)

also on the lines

 

g1 = Start.Substring(12, 4)
g2 = Start.Substring(16, 4)

the variable Start doesn't appear to be initialized before you use it.

 

and in

strStudent(strLetterGrade) = varAverage

strLetterGrade doesn't appear to be initalize either - as well as it being a string not an integer (as pointed out by IcePlug earlier)

 

also not sure what

If Grades(g1, +g2) \ 2 = varAverage Then
    varEveryonesGrade += varAverage
    varEveryonesGrade = Math.Round(varEveryonesGrade / sum)
    txtDsplyClsAvr.Text = "The class average is " &  CStr(varEveryonesGrade)
End If

is doing at all

 

and which line are you getting the Index out of bounds error?

 

the variable sum only seems to be being used as a loop counter but is declared as a double - any reason why?

[Jblake00]

No I am not sure why I had sum as double. It is a counter or was. I may need to do away with it now? Ok lets start over. I made a new text file that contains names only. one name per line. Here is my idea that is the first part of my program. So what I want it to do is simply add the names to a list box in column. But the names are actually the begining of the rows and the grades are the columns. At any rate so far I am haveing no luck.

I almost had it working and changed some things about the text reader and really messed it up.

any way if I could work out the first part first the I could go on to the rest of it.

Here is my thoughts.

 dim the stream reader
Dim names() As String = {"student"}
       Dim i, keepCount As Integer
keepCount = 0
If IO.File.Exists("a:\name.txt") Then
           names(i) = myReader.ReadToEnd()
           Do While myReader.Peek <> -1
               keepCount += 1
               myReader.ReadLine()

           Loop
           my.Close()

           ReDim names(keepCount)
           myReader = IO.File.OpenText("a:\name.txt")
           myReader.ReadLine()
           lstBox.Items.Clear()
           For i = 1 To keepCount
               names(i) = myReader.ReadLine


               lstBox.Items.Add(names(i))
           Next

if I could get that to work then perhaps I could build from there.

[PlausiblyDamp]

firstly

names(i) = myreader.ReadToEnd()

will read the entire file into the first item of the names array - probably not what you intended.

 

Try something like...

 

Dim myReader As System.IO.StreamReader
	Dim names() As String
	Dim i As Integer = 0
	Dim line As String

	myReader = IO.File.OpenText("a:\name.txt")
	lstBox.Items.Clear()

	Do

		ReDim Preserve names(i)
		line = myReader.ReadLine
		names(i) = line
		If Not line Is Nothing Then lstBox.Items.Add(names(i))
		i += 1
	Loop Until line = Nothing

 

although you may be able to do it easier using string.split

Dim myReader As System.IO.StreamReader
Dim names() As String
Dim line As String

myReader = IO.File.OpenText("a:\names.txt")
lstBox.Items.Clear()

line = myReader.ReadToEnd
names = line.Split(Environment.NewLine)
lstBox.DataSource = names

although you may need to mess with the line.Split(...) bit to get the correct line terminator in.

[Jblake00]

Ok keep that in mind for the next part not sure if I got to use the split command yet. I got the first part finally, here it is.

Private Sub btn1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btn1.Click
       Dim my As IO.StreamReader
       Dim names() As String = {"student"}
       Dim i, keepCount As Integer
       Dim start As String
       keepCount = 0
       '
       If IO.File.Exists("a:\name.txt") Then
           my = IO.File.OpenText("A:\name.txt")
           Do While my.Peek <> -1
               start = my.ReadLine
               keepCount += 1
               '
           Loop
           my.Close()
           my = IO.File.OpenText("a:\name.txt")

           ReDim names(keepCount)
           For i = 1 To keepCount
               names(i) = CStr(my.ReadLine)
               lstBox.Items.Add(names(i))
           Next
           my.Close()

       End If

   End Sub
End Class

of I realize that many of you are much more advance than I am at this sort of thing. But hey when I started I knew absolutely nothing about programing and know at least I know a little.

I have to add a nested loop to what I got so far, also some grades to the text file. then I am going to have to get them into zones, that display the name 2 grades an average and a letter grade. then I have to display the average of the class in a text box.

The most confusing thing to me was mentioned before. It is the part were I divide the 2 grades to get the average. As I was asked before and someone didn't understand what I was doing.

Well the idea is (grade1 + grade2) /2 or " is divided by 2 " and that gives the average. only thing I am unsure of if that is how it is done in this program. Maybe it is more like row1 & col 4 + col 5 / 2 = average ????

[PlausiblyDamp]

You really don't need to open and read the file twice - see my above post (1st sample) on how to do it opening the file only once.

 

you could also use the split command to split the line you read in into it's seperate columns.

dim vals() as string
vals = line.split(" " )    'will split on space
'based on your example earlier of a line being tod 89 64
'vals(0) would = tod
'vals(1) would = 89
'and vals(2) would = 64

[Jblake00]

Ok I see your point. Unfornunately I have a set of guidelines that I have to go by. I have learned these guidelines take a simple problem and make a mountain out of a mole hill. so in another words I have to have name() or student() as a string and grades(,) as double,however he said we had thus far used substring(0,11) and did hint that we would have to figure out another way to do it. So now you have me wandering if. vals(student) and vals(grade1, grade2) would work out? at any rate fixing to try something on the second part

[Jblake00]

Ok I added the grades to the file and when I used the script from above that showed all names and grades.

So I dug thought my collection of pages that I printed off from the micrsoft vb sight and came up with this. I change the line

names(i) = CStr(my.ReadLine)

To this

names(i) = my.ReadLine.ToCharArray(0, 11)

Walla names without the grades.

Btw I am not ignoreing what you are saying about opening and closeing the streamreader, but as I said before, " I got certain guidelines I must folllow."... I am quit certain you and many others could do the program in "probably" 10 minutes...

But I think that it has to do with keep up with the counter. Well I have for afternoons to figure the rest out. Btw this I quite a challange for someone who is a framer and also dropped out of high school in the tenth grade.

I am trying to become a computer tech, before my back gets more degenerating and heriated disk than it already has.

So far the with the programs I have done excellent with, but I freeze up on the test,,,,,errrrr.

Any links that may help me learn are welcome. I do well on remembering what I read as long as I is simplified to to were a beginer to an intermediate level of understanding. I am definitly not ready for to advanced programing skills yet.

But hay I am getting there, slowly but surely.

[Iceplug]

So, what does your code look like now?

And where are those grades coming from? Have you already averaged those?

Seems as though, since grades is a 2D array, you would be using a nested for loop on the grades. :-\

[Jblake00]

Yes That is what I am atempting. here is the code now.

But is not showing or adding the grades or the rest of the items.

 Dim my As IO.StreamReader
       Dim fmtStr As String = "{0,11}{1,4} {2,8}  {3,6}     {4,6}"
       Dim grades(,) As Double
       Dim f As Double
       Dim s As Double
       Dim grade1, grade2, total As Double
       Dim varAverage As Double
       Dim sdtLetterG As Double
       Dim names() As String
       Dim student As String
       Dim i, keepCount As Integer
       Dim start As String
       keepCount = 0
       '
       If IO.File.Exists("a:\name.txt") Then
           my = IO.File.OpenText("A:\name.txt")
           Do While my.Peek <> -1
               start = my.ReadLine
               keepCount += 1


           Loop
           my.Close()
           my = IO.File.OpenText("a:\name.txt")


           ReDim names(keepCount)
           ReDim grades(keepCount, 2)
           For i = 1 To keepCount
               start = my.ReadLine
               names(i) = start.ToCharArray(0, 11)

               lstBox.Items.Add(names(i))
           Next
           For keepCount = f To s
               ' 
               f = grades(f, 2) = start.Substring(12, 4)
               f = grade1
               lstBox.Items.Add(f)
               '
               s = grades(1, s) = start.Substring(16, 4)
               s = grade2
               lstBox.Items.Add(s)
               'varAverage = Math.Round((grade1 + grade2) / 2)
               'total += varAverage




           Next
           'total = Math.Round(varAverage / keepCount)
           For sdtLetterG = 1 To keepCount

           Next
           Select Case varAverage
               Case Is >= 90
                   sdtLetterG = "A"
               Case Is >= 80
                   sdtLetterG = "B"
               Case Is >= 70
                   sdtLetterG = "C"
               Case Is >= 60
                   sdtLetterG = "D"
               Case Is >= 50
                   sdtLetterG = "F"
           End Select

           'lstBox.Items.Add(String.Format(fmtStr, names(i), grade1, grade2, varAverage, sdtLetterG))

           my.Close()
           varAverage = Math.Round((grade1 + grade2) / 2)
           total += varAverage


           total = Math.Round(total / keepCount)

           txtDsplyClsAvr.Text = "The class average is " & CStr(total)

       Else

           MsgBox("Try putting in the disk that has grades.txt on it!", , "Missing Disk")
           lstBox.Items.Add(String.Format(fmtStr, names(i), grade1, grade2, varAverage, sdtLetterG))


       End If

   End Sub

[Jblake00]

  Dim my As IO.StreamReader
       'Dim fmtStr As String = "{0,11}{1,4} {2,8}  {3,6}     {4,6}"
       Dim grades(,) As Double
       Dim row, col As Integer
       Dim f As Double
       Dim s As Double
       Dim grade1, grade2, total As Double
       Dim varAverage As Double
       Dim sdtLetterG As Double
       Dim names() As String = {"0,11", "{1,4}", "{2,8} ", "{3,6} ", "{4,6} "}

       Dim student As String
       Dim i, keepCount As Integer
       Dim start As String
       keepCount = 0
       '
       If IO.File.Exists("a:\name.txt") Then
           my = IO.File.OpenText("A:\name.txt")
           Do While my.Peek <> -1
               start = my.ReadLine
               keepCount += 1
               

           Loop
       End If

       my.Close()


       my = IO.File.OpenText("a:\name.txt")
       ReDim names(keepCount)
       ReDim grades(grade1, grade2)
       For i = 1 To keepCount

           start = my.ReadLine
           names(i) = start.Substring(0, 11)
           lstBox.Items.Add(names(i))


       Next

       If IO.File.Exists("a:\name.txt") Then
           my = IO.File.OpenText("A:\name.txt")
           Do While my.Peek <> -1

               For varAverage = keepCount To 2
                   'varAverage += Math.Round(grades(Grade1, + Grade2)) / 2)
               Next

               start = my.ReadLine
               grade1 = start.Substring(12, 4)
               lstBox.Items.Add(grade1)
               grade2 = start.Substring(16, 4)
               lstBox.Items.Add(grade2)
               'lstBox.Items.Insert(grade1, grade2)




           Loop


           'lstBox.Items.Add(varAverage)
           'varAverage = grades(grade1, grade2) / 2 = start.Substring(12, 8)
           'lstBox.Items.Add(grades(grade1, grade2))


           'varAverage = Math.Round((grade1 + grade2) / 2)
           'total += varAverage

           '  Do Until my.Peek <> -1



           total = Math.Round(varAverage / keepCount)
           For sdtLetterG = 1 To keepCount

           Next
           Select Case varAverage
               Case Is >= 90
                   sdtLetterG = "A"
               Case Is >= 80
                   sdtLetterG = "B"
               Case Is >= 70
                   sdtLetterG = "C"
               Case Is >= 60
                   sdtLetterG = "D"
               Case Is >= 50
                   sdtLetterG = "F"
           End Select

           ' lstBox.Items.Add(String.Format(fmtStr, names(i), grade1, grade2, varAverage, sdtLetterG))

           my.Close()

           total += varAverage


           total = Math.Round(total / keepCount)

           txtDsplyClsAvr.Text = "The class average is " & CStr(total)

       Else

           MsgBox("Try putting in the disk that has grades.txt on it!", , "Missing Disk")
           ' lstBox.Items.Add(names(i), grade1, grade2, varAverage, sdtLetterG))
       End If

This code produces all of my names and grades, however it is not seperating them into the rows and columns. Instead it is placeing the grades under the names? Aslo I have no idea on how to get the names grades, averages, and letterGrade into zones as I done on the program before?

[Iceplug]

In order to get the data to show up on the same line, you'll probably have to use a Tab and add everything to the listbox that you want to be on a row at once.

Or, you can use some sort of table/grid control.

 

You'll also need to bring back your counter while you read the file to get the grades.

lstBox.Items.Add(names(i) & " - " & grade1 & " - " & grade2)

or something similar to that.

 

And I don't know what you mean by a zone.

:)

[Jblake00]

Here is the final code for that program.

Private Sub btn1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btn1.Click

       Dim my As IO.StreamReader
       Dim fmtStr As String = "{0,1}{1, 4}{2,5} {3,6}  {4,11}  {5,4}{6,3}" ' BTW HERE IS WHAT MAKES THE ZONES!!
       Dim student, start, temp, strLetterGrade, studentName() As String
       Dim intCount, name, row, col, average As Integer
       Dim total, grades(,), intStart As Double
       intCount = 0
       If IO.File.Exists("A:grades.txt") Then
           my = IO.File.OpenText("A:grades.txt")
           Do While my.Peek <> -1
               student = my.ReadLine
               intCount += 1

           Loop
       


           my.Close()
           my = IO.File.OpenText("A:grades.txt")
           ReDim studentName(intCount)
           ReDim grades(intCount, 2)
           '       Array.Sort(studentName)
           For name = 1 To intCount
               start = my.ReadLine
               studentName(name) = start.Substring(0, 11)
               intStart = 12
               For col = 1 To 2
                   grades(name, col) = start.Substring(intStart, 4)
                   intStart = intStart + 4
                   average += CInt(grades(name, col))

               Next
               'average = cint(grades(name, 1) + grades(name, 2)
               average = average / 2
               Select Case average
                   Case Is >= 90
                       strLetterGrade = "A"
                   Case Is >= 80
                       strLetterGrade = "B"
                   Case Is >= 70
                       strLetterGrade = "C"
                   Case Is >= 60
                       strLetterGrade = "D"
                   Case Is >= 50
                       strLetterGrade = "F"
               End Select
               total = Math.Round(average + total / intCount)
               lstGrades.Items.Add(String.Format(fmtStr, studentName(name), grades(name, 1), "", grades(name, 2), average, "", strLetterGrade))
               average = 0

           Next

           Select Case total
               Case Is >= 90
                   strLetterGrade = "A"
               Case Is >= 80
                   strLetterGrade = "B"
               Case Is >= 70
                   strLetterGrade = "C"
               Case Is >= 60
                   strLetterGrade = "D"
               Case Is >= 50
                   strLetterGrade = "F"
           End Select
           'total = Math.Round(total / intCount, 0)
           txtDsplyClsAvr.Text = "The class average is " & CStr(total) & " " & (strLetterGrade)

           my.Close()
       Else
           MsgBox("Try putting in the disk that has grades.txt on it!", , "Missing Disk")
       End If


   End Sub
End Class

Now to figure out how to make it sort into an aphabetical order and make the grades follow along too.

[Iceplug]

Looks like you're going to need to make your own Sorting.

You may be able to make a copy of the array, sort one of them, and then find where the names have moved by looking at the old array, then the new array, and then moving the grades in the grade array by the same amount :).

[PlausiblyDamp]

if you look at the overloads of Array.Sort - one takes two arrays - try that one.

[Jblake00]

Yea I got it. One problem though it is a strange calculation with the average. I will get figured out soon. Onething I know for sure is that even after taking this course on vb.net. I have only touched the tip of an iceberg..