vb.net if statement between range of numbers

Question

is there a way in vb.net that i can run an if statement to say if a variable starts with 07 then between 1-9

i know i could do this using substring which would work but it would make the if statement rather large

number_called.Substring(0, 3) = "071" or number_called.Substring(0, 3) = "072"

and so on up to 079 but can i create a shorter if statement for the whole range?

Answer 1

This would do it

Private Function CheckNumber(myNumber As String) As Boolean
    Dim regex As Regex = New Regex("^07[1-9]]")
    Dim match As Match = regex.Match(myNumber)
    Return match.Success
End Function

Just call CheckNumber("071") or CheckNumber(number_called)

Remember to import the references Imports System.Text.RegularExpressions

Updated Expression, thank you Veeke

Answer 2

If you know that it will always start with 3 numbers you can parse it

Dim num = Int32.Parse(number_called.Substring(0, 3))
Dim Valid= num>69 and num<80

If you dont know if it will start with 3 numbers, surround it with a TryCatch

Answer 3

You could use String.StartsWith("07") and check the last character of the String - it must be a number and not 0 like this:

If str.Length = 3 And str.StartsWith("07") And Char.IsNumber(str(2)) And str(2) <> "0" Then

End If

Answer 4

Small correction on Malcor's post, which doesn't check if it begins with '07' (just if it contains '07'):

Private Function CheckNumber(myNumber As String) As Boolean
    Dim regex As Regex = New Regex("^07[1-9]")
    Dim match As Match = regex.Match(myNumber)
    Return match.Success
End Function

Answer 5

You could use StartsWith coupled with a Select Case if you are sure it is always a numeric string:

If number_called.StartsWith("07") Then
    Select Case CInt(number_called.SubString(2, 1))
    Case 1 to 9
         'it matched
    Case Else
         'it didn't match
    End Select
End If