Moving Comma-seperated string into a 2d array.

[mike55]

Hi

 

I am using the following code to obtain a response from a web page:

objRequest = System.Net.HttpWebRequest.Create(HttpPaymentRequestUrl(receiptCode))
           objResponse = objRequest.GetResponse()

 

I am using a StreamReader to convert the return into a string:

Dim sr As New StreamReader(objResponse.GetResponseStream())
result = sr.ReadToEnd

 

I want to take the result returned from the web request and put it into an array, preferabily a 2d array.

 

Here is a sample of the web request:

https://www.gatewayURL/EPG/QUERY?Receipts=21051541119&Login_Name=XXX&Logi

n_Password=XXXX&Version=2.0

 

Here are the results that I get back:

Receipt,Identifier,Amount,Auth,ReasonCode,Status,Batch

21051541119,test,0.2,REFERRAL A,02,F,

 

I know that I can do it by doing a loops to determine how many "," are in the string, followed by a loop that gets each value and inserts it into the array.

 

Is there instead a more effective approach, I know that when you want to convert an array to a comma-seperated string you can use the command:

String.Join(",", arrayName)

 

Is there any method that does the reverse? Alternatively, can I use datatables?

 

Mike55.

Edited January 24, 2007 by mike55

[PlausiblyDamp]

dim s as string = "One, Two, Three"
dim x() as string = s.Split(",")

 

The above will return an array of strings - one element per value between the separator specified.

[mike55]

dim s as string = "One, Two, Three"
dim x() as string = s.Split(",")

 

Yea, came across the above code else where and used it. I also had to use a char() to store the split elements as when I did a quick watch on the string, I found that there was also a carriage return. Given that the carriage return indicates a new line is there any way to split the string into a 2d array?

 

Mike55.

[MrPaul]

2D array vs jagged array

 

There is no simple way of using Split to obtain a 2D array. If there are an equal number of elements on each line, then it could be achieved by using the first line as a size guide:

 

Untested code:

 

Dim values(,) As String
Dim lines() As String
Dim parts() As String

'Get lines
lines = myString.Split(ControlChars.Lf) 'Use appropriate line separator
parts = lines(0).Split(","c)

'Resize output array
ReDim values(lines.Count - 1, parts.Count - 1)

For i As Integer = 0 To lines.Count - 1

   'Get values of this line
   parts = lines(i).Split(","c)

   'Copy parts into 2D array
   For j As Integer = 0 To parts.Count - 1
       values(i, j) = parts(j)
   Next
Next

 

However, if the number of values on each line varies, you are probably best using a jagged array (infact I would recommend this either way). This basically consists of an array of arrays:

 

Dim values()() As String
Dim lines() As String

'Get lines
lines = myString.Split(ControlChars.Lf) 'Use appropriate line separator

'Resize output array
ReDim values(lines.Count - 1)

For i As Integer = 0 To lines.Count - 1
   'Get values for this line
   values(i) = lines(i).Split(","c)
Next

 

Now the jth value on line i can be referenced by values(i)(j).

 

Good luck :cool:

[travisowens]

Too bad the RegularExpression objects don't have their own Split, you could probably write a pretty flexible split based on regex.

[mike55]

Here is the final version of the code, it is optimised for dealing with the Malta based payment gateway endeavour:

       Private Function GetParameterValue(ByVal csString As String, ByVal searchValue As String) As String
           Dim values()() As String
           Dim lines() As String

           'Get lines
           lines = csString.Split(System.Environment.NewLine) 'Use appropriate line separator

           'Resize output array
           'Dim i As Int16 = 0
           'While i <= (lines.Length - 1)

           'End While
           'ReDim values(lines.Length - 1)
           ReDim values(0)

           Dim position As Int16 = 0

           'Take the return and put it into a 2d array.
           For i As Integer = 0 To (lines.Length - 1)
               Select Case String.IsNullOrEmpty(lines(i).ToString)
                   Case False
                       'Check to determine if the line contains valid data, some lines come back with a character with the ascii code 10
                       Select Case lines(i).Contains(",")
                           Case True

                               'Increase the size of the array if needed.
                               Select Case position
                                   Case 0
                                       'do nothing
                                   Case Is > 0
                                       ReDim Preserve values(position)
                               End Select

                               'Get values for this line
                               values(position) = lines(i).Split(","c)
                               position += 1

                           Case False
                               'do nothing
                       End Select

                   Case True
                       'do nothing
               End Select

           Next

           'In the event that the first character of the first value of each line has an ASCII value of 10, remove that character.
           For i As Integer = 0 To (values.Length - 1)
               Select Case Asc(values(i)(0).Chars(0)).ToString
                   Case "10"
                       values(i)(0) = values(i)(0).Remove(0, 1)
               End Select
           Next

           'Begin looking for the searchValue
           Dim parameterValue As String = Nothing
           Dim aLength As Int16 = 0
           Dim aHeight As Int16 = 0
           Dim pos As Int16 = 0

           'Get the length of the array and begin iterating though it untill parameter located.
           aLength = values(0).Length
           aHeight = values.Length

           While pos < aLength - 1
               If values(0)(pos).ToLower = searchValue.ToLower Then
                   parameterValue = values(aHeight - 1)(pos)
                   Exit While
               End If
               pos += 1
           End While

           Return parameterValue
       End Function

 

Alternatively, if anyone wants to refactor the code, fire away.

 

Mike55.

[MrPaul]

Refactoring

 

Rather than constantly resizing an array, I would suggest using a List(Of String()) (from System.Collections.Generic). This will be more efficient and will deal with the resizing of the collection automatically.

 

For the second For loop, you could use the TrimStart method of the string, rather than checking the first character:

 

For Each line As String() In values
   line(0) = line(0).TrimStart(ControlChars.Cr)
Next

 

However, from the looks of your last For loop, you're only interested in values taken from the last line of data, using the first line as column guide. This would mean there is no real need to store every other line in an array or collection, you may as well just parse the first and last lines:

 

Dim lines() As String
Dim colnames() As String
Dim lastrow() As String

'Get lines
lines = csString.Split(Environment.NewLine)

'Get column names
For Each line As String In lines
   If (line.Contains(",")) Then
       colnames = line.Split(",")
       Exit For
   End If
Next

'Get last line (as above, searching backwards)
Array.Reverse(lines)
For Each line As String In lines
   If (line.Contains(",")) Then
       lastrow = line.Split(",")
       Exit For
   End If
Next

'Find appropriate index in colnames here, then take value from lastrow

 

Good luck :cool: