Strange ASC Codes

Question

Hello all, I'm not familiar with chars and encodings, but need to filter input strings char by char and just allow few chars to pass out

Convert.ToInt32(InputString.Chars(LoopNo))

I'm confused with some chars ASC codes, like:

133 which is Horizontal ellipsis … but in some conditions I get 8230 instead of 133

146 which is Right single quotation mark ’ but in some conditions I get 8217 instead of 146

Each char has 2 ASC codes?
How to cover them all in my function?

For LoopNo As Integer = 0 To InputString.Length - 1
Select Case Convert.ToInt32(InputString.Chars(LoopNo))
Case 133, 146, etc...
OutString += InputString.Chars(LoopNo)
Case Else
'Disregard
End Select
Next

Answer 1

Hi
I would do something like this. Lots of room for improvements as I don't really know what you are planning on.

Public Class Form1  
	Dim teststring As String = "1  2A" & Chr(133) & "BA C" & Chr(146) & "de fA"  
	Dim wanted() As Integer = {65, 133, 146}  
	Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load  
  
		Dim OutString As String = GetChars(teststring)  
		Stop  
		' hover over the OutString variable above to see what it holds.  
		' Here it is "A…A’A"  
	End Sub  
	Function GetChars(s As String) As String  
		Dim newstring As String = Nothing  
		For Each c As Char In s  
			If wanted.Contains(Asc(c)) Then newstring &= c  
		Next  
		Return newstring  
	End Function  
End Class  

Answer 2

I guess you mean more ASCII code, not ASC(ending)

but in some conditions I get 8217 instead of 146

ASCII can represent max. 255 characters = 1 byte in size. Unicode uses 2 bytes = can have value higher then 255, see https://www.codetable.net/decimal/8217

Answer 3

Hi
See THIS LINK for some info.

As for your code. Do you want to add multiple characters to the OutString when it already has that character? e.g. InputString = "ABCDAFGAHIJ" so OutString would contain character 'A' value 3 times. or, if already in OutString would only contain the value for 'A' once?