Sort a String array - regex

Question

I have as input the string in the below format
"[1_5,3,7,1],[1_2,4,1,9],[],[1_1,,4,,,9,2]"
What I need to obtain is the same string but with the number after the _ sorted:
"[1_1,3,5,7],[1_1,2,4,9],[],[1_1,2,4,9,,,]"
Dim tmprequestedArea_selectionAreaIn As String = "[1_5,3,7,1],[1_2,4,1,9],[],[1_1,,4,,,9,2]"
tmprequestedArea_selectionAreaIn = Regex.Replace(requestedArea_selectionAreaIn,"\],\[","#")
tmprequestedArea_selectionAreaIn = Regex.Replace(tmprequestedArea_selectionAreaIn,"\[|\]","")
bracList.AddRange(tmprequestedArea_selectionAreaIn.Split(New Char() {"#"c}, StringSplitOptions.None ))
If sortNumber Then
'Split braclist by _ and puts the value in strList
'If after _ is only one number put only that number, else split it by char "," and put in strList the join of the split by , array
'Sort the array
'in previous example strList will contain a,b,c in position 0 and _d_f (instead of f,d) in position 1
For i As Integer = 0 To bracList.Count -1
Dim tmp As String()
Dim tmpInt As New System.Collections.Generic.List(Of Integer)
If Not(String.IsNullOrEmpty(bracList(i))) Then
Dim tmpRequested As String = bracList(i).Split(New Char() {"_"c})(0)
Dim tmpSelection As String = bracList(i).Split(New Char() {"_"c})(1)
If tmpSelection.Contains(",") Then
tmp = tmpSelection.Split(New Char() {","c})
For j As Integer = 0 To tmp.Length -1
tmpInt.Add(Convert.toInt32(tmp(j)))
Next
tmpInt.Sort
strList.Add("[" + tmpRequested + "_" + String.Join(",",tmpInt ) + "]")
Else
strList.Add("[" + tmpRequested + "_" + tmpSelection + "]" )
End If
Else
strList.Add("[]")
End If
Next i
I'm looking for a better way to manage it.

Answer 1

Try this, as a possible substitute for what you're doing now.
Given this input string:
Dim input As String = "[1_5,3,7,1],[1_2,4,1,9],[],[1_1,,4,,,9,2]"
Note: this will also deal with decimal values without changes. E.g.,
"[1_5.5,3.5,7,1],[1_2.564,4,2.563,9],[],[1_1,,4.23,,,9.0,2.45]"
You can extract the content of the brackets with this pattern: \[(.*?)\] and use Regex.Matches to return a MatchCollection of all the substrings that match the pattern.
Then use a StringBuilder as a container to rebuild the string while the parts are being treated.
Imports System.Linq
Imports System.Text.RegularExpressions
Dim pattern As String = "\[(.*?)\]"
Dim matches = Regex.Matches(input, pattern, RegexOptions.Singleline)
Dim sb As New StringBuilder()
For Each match As Match In matches
Dim value As String = match.Groups(1).Value
If String.IsNullOrEmpty(value) Then
sb.Append("[],")
Continue For
End If
Dim sepPosition As Integer = value.IndexOf("_"c) + 1
sb.Append("[" & value.Substring(0, sepPosition))
Dim values = value.Substring(sepPosition).Split(","c)
sb.Append(String.Join(",", values.Where(Function(n) n.Length > 0).OrderBy(Function(n) CDec(n))))
sb.Append(","c, values.Count(Function(n) n.Length = 0))
sb.Append("],")
Next
Dim result As String = sb.ToString().TrimEnd(","c)
If you don't know about LINQ, this is what it's doing:
String.Join(",", values.Where(Function(n) n.Length > 0).OrderBy(Function(n) CDec(n)))
values is an array of strings, generated by String.Split().
values.Where(Function(n) n.Length > 0): creates an Enumerable(Of String) from values Where the content, n, is a string of length > 0.
I could have written values.Where(Function(n) Not String.IsNUllOrEmpty(n)).
.OrderBy(Function(n) CDec(n))): Orders the resulting Enumerable(Of String) using the string value converted to Decimal and generates an Enumerable(Of String), which is passed back to String.Join(), to rebuild the string, adding a char (","c) between the parts.
values.Count(Function(n) n.Length = 0): Counts the elements of values that have Length = 0 (empty strings). This is the number of empty elements that are represented by a comma, appended at the end of the partial string.

Answer 2

If you are looking for a "way"
I think it is easier to fetch each char of the string and if it is a number you put it in array (and when the char is ']' you start new array) the sort the arrays and replace each number from the string with it's sorted number (so you will just do allocation without the need to reconstruct with regular expression
I wish that I had Visual Studio to provide you the code (it is joyful to code a riddle) ^_^
ps:for the commas you can use a counter for each blank commas an the put it in the end