Resolved Arrays with Option Strict On

[Gorkfu]

I am new to VB.net, I've only been messing with it for a few weeks. However I'm not new to coding, been an avid php coder for the last few years. Anyways on to my issue.

I found some code written for VB6 for extracting text within tags. I took it and modified it for VB.net, not much was needed to be modified. I ended up with the following code.

    Public Function ExtractIt(ByVal TextIN As String, Optional ByVal StartTag As String = " ", Optional ByVal EndTag As String = " ") As String
        On Error GoTo LocalError

        Dim lArray As Object
        ExtractIt = ""
        lArray = Split(TextIN, StartTag)
        If IsArray(lArray) Then
            ExtractIt = lArray(1)
            lArray = Split(ExtractIt, EndTag)
            If IsArray(lArray) Then
                ExtractIt = lArray(0)
            Else
                ExtractIt = ""
            End If
        End If
        Exit Function

LocalError:
        ExtractIt = "Didn't Work!"
    End Function

The code works fine if I have the strict option off, however I'm in the habit of leaving it on and want to keep that habit.

With option strict on I get an error, "Option Strict On disallows late binding." If I understand correctly it means I can't bind an array or part of an array to a variable with option strict on.

Error shows up on these lines:
ExtractIt = lArray(1)
ExtractIt = lArray(0)

How do i change the arrays to work properly with "Option Strict On"?

Original code can be found here:
Extract Text Within Tags

 

[Robert_Zenz]

Hello.

Try this instead. Maybe the error occured 'cause you defined lArray as Object instead as String.

    Public Function ExtractIt(ByVal TextIN As String, Optional ByVal StartTag As String = " ", Optional ByVal EndTag As String = " ") As String
        Try
            Dim lArray As String() = Split(TextIN, StartTag)
            ' ??? ExtractIt = ""

            If IsArray(lArray) Then
                ExtractIt = lArray(1)
                lArray = Split(ExtractIt, EndTag)
                If IsArray(lArray) Then
                    ExtractIt = lArray(0)
                Else
                    ExtractIt = ""
                End If
            End If
        Catch ex as Exception
            ExtractIt = "Didn't Work!"        
        End Try
    End Function

Alternative to it, you could use Regular Expressions:

Imports System.Text.RegularExpressions

Public Function ExtractIt(ByVal text as String, Optional byVal StartTag as String = " ", Optional ByVal EndTag as String = " ") as List(Of String)

      Dim matches as New List(Of String)

      For each match as Match in RegEx.Matches(text, StarTag & "[a-zA-z0-9-!"#$%&'()*+,./:;<=>?@\[\\\]_`{|}~]* & EndTag)
            matches.Add(match.Value)
      Next

      Extractit = matches
End Function

But there might an issue there, if you use this function to split a string, since the last and the first word doesn't match this pattern, instead I'd use the Split() Function.

Bobby

 

[Sehnsucht]

Gorkfu, Option Strict disallows implicit Type conversion, but in the two error lines you make implicit conversion from object to string

First solution: convert to string

ExtractIt = lArray(1).ToString()

Better solution: create an array of String (strongly typed)

Dim lArray As String()

 

[Gorkfu]

Thanks for the help guys, changing the lArray variable to a string fixed the problem. However, using .tostring or even Cstring to convert the arrays would not work. I'm not sure why, but maybe someone could explain that one. I actually attempted the conversions before my original post.

Now I understand the difference between implicit and explicit conversions and it helps to understand them, lol.

 

[Gorkfu]

I just realized why the .tostring and Cstring conversions did not work. It's the fact that the original code was like this:

Dim lArray As Object

When it should have been:

Dim lArray As Object()

 

[kaisellgren]

Great. I solved my issue with this, too:

Public Instances As Object()