[dbaliki918]

This is the code i have thus far, using Visual Basic 2010 Express:

Public Class Form1
    Dim playername As String
    Dim level As String
    Dim country As String
    Dim alliance As Integer

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load


        playername = InputBox("What is your Player Name?")
        level = InputBox("What is your level?")
        If Char.IsLetter(level) Then
            '**************************************************************************************************
            'I want to know how to go back to the "level" input box  instruction if the input contains letters.
            '**************************************************************************************************
        ElseIf Char.IsNumber(level) Then

        End If

        country = InputBox("What is your country?")
        alliance = InputBox("What is the size of your alliance?")
    End Sub
End Class

[AdamSpeight2008]

What does that suggest to you need?
To me some for conditional loop. Do ... While / Do ... Until

[torind_2000]

Wouldn't something like this work?

        If Char.IsLetter(CChar(level)) Then
            Do Until Char.IsNumber(CChar(level))
                level = InputBox("What is your level?")
            Loop
        ElseIf Char.IsNumber(CChar(level)) Then

[sela007]

or the simplest way

1:
level = InputBox("What is your level?")
If Char.IsLetter(level) Then goto 1

[Curtis Rutland]

Did you really just suggest goto?

[sela007]

Curtis Rutland, on 02 February 2012 - 06:21 PM, said:

Did you really just suggest goto?

it's just another way. Whats wrong with that?

[nK0de]

sela007, on 03 February 2012 - 02:17 PM, said:

Curtis Rutland, on 02 February 2012 - 06:21 PM, said:

Did you really just suggest goto?

it's just another way. Whats wrong with that?

LOL

[Atli]

sela007, on 03 February 2012 - 08:47 AM, said:

it's just another way. Whats wrong with that?

The goto statement makes it very very easy to create spaghetti code (which is easy enough as it is), and it makes your code unpredictable. - If you place a label, especially one that vague, in a routine, you can call that at a any point in the routine. You'll have to waste time trying to figure out why the label was placed there and at what points in the routine it is called. There is no structure to it.

Meanwhile, these versions of your code are 100% obvious:

Do 
    level = InputBox("What is your level")
Loop While Char.IsLetter(level)

While !CharIsNumber(level)
    level = InputBox("What is your level")
End While

They even read like plain English. As far as simplicity goes, where exactly does the goto get simpler than this?

There is never any reason to use a goto in a language like VB.NET. It has structured control statements, like the DO loop, that can be used to produce any result, without the use of a goto.

[sela007]

Atli, on 03 February 2012 - 04:22 AM, said:

There is never any reason to use a goto in a language like VB.NET. It has structured control statements, like the DO loop, that can be used to produce any result, without the use of a goto.

I don't agree with you. If you know how to use it and when, then there is no problem. Sometimes it's useful to avoid spaghetti code , especially when you have a complex code with bunch of select case statements ,and loops.

[Curtis Rutland]

At best it's rarely useful. One of the only places it's acceptable to use is to escape from a deeply nested series of conditionals or loops, but I'd say that it's bad practice to write code that needs it in the first place. It can always be refactored to reduce nesting, at the very least by extracting methods.

The point is, suggesting goto as a replacement for a basic loop is bad advice, no matter how you want to spin it.

[sela007]

Curtis Rutland, on 03 February 2012 - 06:55 AM, said:

The point is, suggesting goto as a replacement for a basic loop is bad advice, no matter how you want to spin it.

i agree with that. I just wanted to dbaliki918 knows that there are many ways to repeat the line of code.
first is Do ... While / Do ... Until.. like AdamSpeight2008 said... goto is last alternative,it's bad but it can do the job ...

[smohd]

sela007, on 03 February 2012 - 07:56 PM, said:

... goto is last alternative,it's bad but it can do the job ...

And we do not advice bad practices here, if there is a best practice, always use it. That is all previous replies were saying. And we already have a topic about GOTO in JavaVB.net Advanced discussion forum

This post has been edited by smohd: 03 February 2012 - 08:08 AM

[no2pencil]

sela007, on 03 February 2012 - 03:47 AM, said:

Curtis Rutland, on 02 February 2012 - 06:21 PM, said:

Did you really just suggest goto?

it's just another way. Whats wrong with that?

Goto is used best in interpreted languages. In a language that is compiled & uses functions, Goto should be avoided. It's simply too elementary code structure for a compiled language.