Remove special characters from a string

Question

These are valid characters:

a-z
A-Z
0-9
-
/

How do I remove all other characters from my string?

Which characters aren't special? Do you want the cleaned string to only contain `-` and `/` or do you want to keep other characters too? — LukeH, Sep 13 '10 at 13:51
a-zA-Z0-9 and -,/ rest all not needed but mainly right now i need to remove crlf,cr,lf using vb.net — Sriram, Sep 13 '10 at 13:57

score 27 · Answer 1 · answered Sep 13 '10 at 14:17

27

Dim cleanString As String = Regex.Replace(yourString, "[^A-Za-z0-9\-/]", "")

answered Sep 13 '10 at 14:17

LukeH

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Little support requesting.. If I need to exclude a special character from this. Not special character, say If I want white space and # symbol not to be replaced.. how can I modify this.. – Sandeep Thomas Sep 14 '17 at 12:01
@sforsandeep: Just add them into the group, for example: `[^A-Za-z0-9\-/#\s]` or similar. – LukeH Sep 15 '17 at 11:31

score 6 · Answer 2 · answered Sep 13 '10 at 13:54

6

Use either regex or Char class functions like IsControl(), IsDigit() etc. Get a list of these functions here: http://msdn.microsoft.com/en-us/library/system.char_members.aspx

Here's a sample regex example:

(Import this before using RegEx)

Imports System.Text.RegularExpressions

In your function, write this

Regex.Replace(strIn, "[^\w\\-]", "")

This statement will replace any character that is not a word, \ or -. For e.g. aa-b@c will become aa-bc.

answered Sep 13 '10 at 13:54

Sidharth Panwar

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+1 The OP probably wants to keep spaces as well - though maybe not tabs (?) which would be `Regex.Replace(strIn, "[^\w\\- ]", "")` – El Ronnoco Sep 13 '10 at 14:20
Watch out! The `\w` class doesn't only match alphanumerics. For example, your regex won't correctly clean *"a_string_containing_underscores"*. (Also, the OP wants to allow forward-slashes, not backslashes.) – LukeH Sep 13 '10 at 14:26
Hmm. Slash should be different. – Sidharth Panwar Sep 13 '10 at 16:36

score 1 · Answer 3 · answered May 22 '18 at 21:21

1

Dim txt As String
txt = Regex.Replace(txt, "[^a-zA-Z 0-9-/-]", "")

answered May 22 '18 at 21:21

But Jao

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An explanation of the regex would be helpful as part of your answer. – Mary May 22 '18 at 23:25

Anand Vishwakarma · Answer 4 · 2017-01-02T13:09:41.527

0

Function RemoveCharacter(ByVal stringToCleanUp)
    Dim characterToRemove As String = ""
        characterToRemove = Chr(34) + "#$%&'()*+,-./\~"
        Dim firstThree As Char() = characterToRemove.Take(16).ToArray()
        For index = 1 To firstThree.Length - 1
            stringToCleanUp = stringToCleanUp.ToString.Replace(firstThree(index), "")
        Next
        Return stringToCleanUp
End Function

edited Jan 02 '17 at 13:09

answered Jan 02 '17 at 13:04

Anand Vishwakarma

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String.Replace("char", "")? – brandito Jul 26 '18 at 03:48

score 0 · Answer 5 · answered Nov 02 '22 at 00:31

I've used the first solution from LukeH, but then realized that this code replaces the dot for extension, therefore I've just upgraded the code slightly:

 Dim fileNameNoExtension As String = Path.GetFileNameWithoutExtension(fileNameWithExtension)
 Dim cleanFileName As String = Regex.Replace(fileNameNoExtension, "[^A-Za-z0-9\-/]", "") & Path.GetExtension(fileNameWithExtension)

cleanFileName will the file name with no special characters with extension.

Remove special characters from a string

5 Answers5

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