Vb.net reading text file and searching for a number

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Hello dope community, I did search a lot about this but found nothing
so simply I do have 1 textbox, 1 label called "Invalid", 1 button and finally a text file

the text file has numbers in lines or more likely a zip codes written by that way:
"10000
23251
30021
51931
and so on..."
textbox = type the zip code number
button = to search if the number which i did type in the textbox is inside the text file or not
if yes then label1.text = "Valid"

and that's pretty much all of it

I tried the following but I know it's totally wrong + it doesn't work + it will talk so long time to type each and every single number in it

Thank you so much in advance

What I have tried:

nothing so far, I've tried this:

If value1 = 10000 or 23251 or 30021 or 51931 Then
            Label1.Text = "VALID"
        End If

Posted 23-Feb-22 19:09pm

Sam K. Lewis

Updated 23-Feb-22 21:44pm

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2 solutions

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OriginalGriff · Answer 1 · 2022-02-23T19:49:00

Solution 1

Just treat it as text: use File.ReadAllLines to read the file data into an array, then use Linq methods to tell you if there is an exact match:

VB

If linesFromFile.Any(Function(l) l = myTextBox.Text) Then
    label1.Text = "Valid"
End If

Posted 23-Feb-22 19:49pm

OriginalGriff

Comments

Sam K. Lewis 24-Feb-22 9:44am

Thank you so much for your reply, I've tried this:

Dim File As String = "Georgia.txt"
Dim Georgia As String = IO.File.ReadAllLines(File)
If Georgia.Any(Function(l) l = TextBox1.Text) Then
Label1.Text = "Valid"
End If

but not good so far, i think I did a mistake

OriginalGriff 24-Feb-22 10:47am

why do you think that ReadAllLines would return a single string?
If you come across a method you don't recognise, don't guess - check the documentation!

Ralf Meier · Answer 2 · 2022-02-23T21:44:00

Solution 2

independant from the answer from Griff (which is pretty pretty good) your code-snipped would not work. If you want to do something like this your code must look like :

If (value1 = 10000) or (value1 = 23251) or (value1 = 30021) or (value1 = 51931) Then
   Label1.Text = "VALID"
End If

Posted 23-Feb-22 21:44pm

Ralf Meier

Comments

Sam K. Lewis 24-Feb-22 9:45am

That helped a lot, small thing but matters!
I Appreciate you