CODEWITHSUNDEEP
arraysvb.netstringfor-loop
user1959628
user1959628

Reputation: 23

Comparing string with array

I am trying to compare a string variable to an element of a string array using a for loop in visual basic. I am comparing a user-entered string variable to an array with the lowercase alphabet, in order. I have some logical mistake because my "count" variable is always on 25 for some reason, and therefore it always says "Sorry, Try again" unless the user types a Z. Please help!

 Dim lower() As String = {"a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l",    "m", "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z"}
   For count As Integer = 0 To 25
        input = txtInput.Text
        input = input.ToLower
        If input.Equals(lower(count)) Then
            txtResult.Text = "Correct"
        Else
            txtResult.Text = "Sorry, Try again"
        End If
    Next

Upvotes: 2

Views: 3239

Answers (2)

xpda
xpda

Reputation: 15813

The problem is that you should exit the loop (with exit for) after you find a match. Otherwise, any mismatched characters will reset txtResults.Text to "Sorry, Try again." For example, when you enter "f", txtResults.Text is set to "Correct". But when you get to g, currently, it changes txtResults.Text to "Sorry, Try again.", and h, i, etc.

This is a good exercise in programming, but there is a shortcut you can use:

lower.contains(input.lower)

Info:

http://msdn.microsoft.com/en-us/library/dy85x1sa.aspx

Upvotes: 1

Andrey Gordeev
Andrey Gordeev

Reputation: 32459

Welcome to StackOverflow!

The reason you get "Correct" result only if you type "z" is that "z" is the last item of the array. If you type "y", the result will be correct for count = 24 (lower(24) = "y"), but at the next step it compares "y" with lower(25), which is actually "z". So txtResult.Text will be overwritten by "Sorry, Try again".

As I get your task correctly, you want to check if the input string is exists in the array. For that purpose you may use Array.Contains method:

Dim lower() As String = {"a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l",    "m", "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z"}
Dim input As String = txtInput.Text
If (lower.Contains(input)) Then
    txtResult.Text = "Correct"
Else
    txtResult.Text = "Sorry, Try again"
End If

Upvotes: 1

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