Question Using String Replace

Hello all,

I have to convert an Email address before I search a database. I have to Change the (.) Period to an (_) Underscore before I search and the string replace changes ALL the periods to underscore.

I need to replace the period in the Name and not in the .COM


This ([email protected]) needs to be ([email protected])

Using the replace method it turns into this

some_one@here_com

Is there a way to change the first occurrence only?

-NJ

Is it just the 1st occurrence of the period? What if the email address is [email protected]?

This extension method will replace all periods with underscores before the @.

vb.net Code:

Public Class Form1
 
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
 
        Dim email = "[email protected]"
        email.ReplacePeriodEmailUser()
 
    End Sub
End Class
 
Public Module StringExtensions
 
    <System.Runtime.CompilerServices.Extension()>
    Public Sub ReplacePeriodEmailUser(ByRef text As String)
        Dim split = text.Split("@"c)
        text = String.Join("@"c, split(0).Replace("."c, "_"c), split(1))
    End Sub
 
End Module

Well regex is certainly one way, here is another:

Code:

---

        'Some email
        Dim email_string As String = "[email protected]"

        'Get first instance of @
        Dim at_sign As Integer = email_string.IndexOf("@")

        'Loop from the beginning to the @ sign
        For i As Integer = 0 To at_sign
            'If that certain letter is a . then...
            If email_string.Substring(i, 1) = "." Then
                'Replace it with an _
                email_string = email_string.Substring(0, i) & "_" & email_string.Substring(i + 1)
            End If
        Next

---

Edit - MattP beat me!

That is awesome!!!

I never knew of the text.split option.

Thanks,

-NJ

Quote:

---

Originally Posted by NJDevils28

I never knew of the text.split option.

---

Here's the documentation: String.Split Method

You can also use string builder.

Code:

---

        Dim s As String = "[email protected]"
        Dim cpy As New System.Text.StringBuilder(s)

        For x As Integer = 0 To cpy.Length - 1
            If cpy(x) = "."c Then
                cpy(x) = "_"c
                Exit For
            End If
        Next

        s = cpy.ToString

---

This only works if there is a "." before the "@".