仅将混合字符串中的数字相乘[VB.Net]

Question

Let's say I have a string "N4NSD3MKF34MKMKFM53" and i want to multiply the string * 2 to get

N8NSD6MKF68MKMKFM106 How would I go about doing this?

Answer 1

Ok, I might as well give you the Regex solution as long as I'm here. But I caution you not to use it unless you understand what it's doing. It's never a good idea to just copy and paste code that you don't fully understand.

Dim input As String = "N4NSD3MKF34MKMKFM53"
Dim output As String = Regex.Replace(
                                 input, 
                                 "\d+", 
                                 Function(x) (Integer.Parse(x.Value) * 2).ToString())

Answer 2

You can try the following code:

Public Class Program
Public Shared Sub Main(args As String())

        Const  expression As String = "N4NSD3MKF34MKMKFM53"

        Dim  result = MultiplyExpression.Calculate(expression)
        Console.WriteLine(result)
    End Sub
End Class

Class MultiplyExpression
    Public Shared Function Calculate(expression As String) As String
        Dim result = String.Empty
        For  Each c In expression
            Dim num As Integer
            If Int32.TryParse(c.ToString(), num) Then
                result += (num * 2).ToString()
            Else
                result += c
            End If
        Next

        Return result
    End Function
End Class

Output: N8NSD6MKF68MKMKFM106