Check code in loop doesn't working properly - arrays

Question

I made a code capable of downloading values in a web page and it works well. Since the values are taken in real time, that is, data download is performed only when there are actually changes, I need if a certain value is changed.
I then created a code that allows me to get check from all elements of the array with the updated values and the array with the old values.
The code actually detects when a given result has changed, but for some strange reason, the message appears to infinity, as if it were stuck in a foor that takes no arguments, and this is very strange.
For Each abc As Country_Data In lista
For Each xyz As Country_Data In vecchia_lista
If abc.casa = xyz.casa And abc.ospite = xyz.ospite Then
If abc.Result <> xyz.Result Then
MsgBox(abc.casa & " - " & abc.ospite & " -- " & abc.Result)
Exit For
End If
End If
Next
Next
Variable definition
Dim lista As New List(Of Country_Data)
Dim vecchia_lista As New List(Of Country_Data)
Private Structure Country_Data
Dim casa As String
Dim ospite As String
Dim Result As String
End Structure
how to fix this?

Answer 1

Based on your comments, I'm gathering that you only ever want to see one message box, when it finds the first case where a result has changed (even though there could be others after that).
The Exit For you're using only exits from the inner For loop, and thus the outer For loop continues to loop, which is probably what you're observing.
You can do something like this:
Dim keepLooping As Boolean = True
For Each abc As Country_Data In lista
For Each xyz As Country_Data In vecchia_lista
If abc.casa = xyz.casa And abc.ospite = xyz.ospite Then
If abc.Result <> xyz.Result Then
MsgBox(abc.casa & " - " & abc.ospite & " -- " & abc.Result)
keepLooping = False
Exit For
End If
End If
Next
If (Not keepLooping) Then Exit For
Next
That way when you want to stop looping, it will set the boolean flag and that will be observed by the outer loop, causing it to exit as well.