.NET: Extract numbers from string

VB.NET

Shared Function ExtractNumbers(ByVal expr As String) As String
Return String.Join(Nothing, System.Text.RegularExpressions.Regex.Split(expr, "[^\d]"))
End Function

C#

static string ExtractNumbers(string expr)
{
return string.Join(null,System.Text.RegularExpressions.Regex.Split(expr, "[^\\d]"));
}

Call the function as follows

VB.NET

Response.Write (ExtractNumbers("12EFR77"))

C#

Response.Write (ExtractNumbers("12EFR77"));

Output of this Code will be: 1277