how can i extract only letters from text?

Question

      Dim value = "only42letter"

        Dim m As Match = Regex.Match(value, _
                "([A-Za-z]+)", _
               RegexOptions.IgnoreCase)
        If (m.Success) Then
        Dim key As String = m.Groups(1).Value
        MsgBox(key)
        End If

i need to make value "onlyletter" by excluding "42". but key returning "only" or "letter". how can i get whole letters but numbers?

Answer 1

Hi, you can use Regex.Replace to get the string without numbers:

Dim input As String = "only42string"

Dim output As String = Regex.Replace(input, "[\d]", String.Empty)

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Koopakiller [kuːpakɪllɐ] http://koopakiller.ko.ohost.de/

Answer 2

Alternative without regex:

Dim input = "only42letters"

Dim output = String.Join(String.Empty, input.Where(AddressOf Char.IsLetter))

Answer 3

Alternative without regex:

Dim input = "only42letters"

Dim output = String.Join(String.Empty, input.Where(AddressOf Char.IsLetter))

good idea but your code won't run with Option Strict on.

String.Join joins a string array + you're passing it an IEnumerable(Of Char).

try this:

Dim input = "only42letters"
Dim output = String.Concat(input.Where(AddressOf Char.IsLetter).ToArray)

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thanks for any help

Answer 4

this String.Join certainly works with Option Strict On, but I could have used this String.Concat and drop the call at ToArray in your code ;)

Answer 5

this String.Join certainly works with Option Strict On, but I could have used this String.Concat and drop the call at ToArray in your code ;)

that only works with 4+ framework. i tested it in vb2008

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thanks for any help