Question

I'm using Visual Studio to make a grocery app for school that includes usernames and passwords. I'm given all the code then it tells me to use search arrays to implement two functions. They should return true if the username and password is found in the arrays. But i can't seem to get the function and arrays right. Below is the code and I'm supposed to implement the array in the two empty functions at the bottom. Would really appreciate some help here, thanks

Module Main
Friend blnLoggedIn As Boolean
Dim arrUsernames() As String = {"Admin", "Clerk", "Manager"}
Dim arrPasswords() As String = {"password", "password2", "password3"}

Sub Login(username As String, password As String)
blnLoggedIn = False
If VerifyUsername(username) And VerifyPassword(password) Then
'Find index for username
Dim userIndex As Integer
For loopIndex = 0 To arrUsernames.Length - 1
If arrUsernames(loopIndex) = username Then
userIndex = loopIndex
Exit For
End If
Next
'Check for password match
If arrPasswords(userIndex) = password Then
blnLoggedIn = True
Else
MessageBox.Show("Incorrect password.")
End If
End If
End Sub
Function VerifyUsername(username As String) As Boolean

End Function
Function VerifyPassword(password As String) As Boolean

End Function
End Module

Answer 1

VB:

Public Function VerifyUsername(ByVal username As String) As Boolean

For positionInUsernameArray As Integer = 0 To arrUsername.Length - 1

If positionInUsernameArray = arrUsername.Length Then Exit For

If username = arrUsername(positionInUsernameArray) Then

Return True

Else

Continue For

End If

Next

Return False

End Function

Public Function VerifyPassword(ByVal password As String) As Boolean

For positionInUsernameArray As Integer = 0 To arrPassword.Length - 1

If positionInUsernameArray = arrPassword.Length Then Exit For

If password = arrPassword(positionInUsernameArray) Then

Return True

Else

Continue For

End If

Next

Return False

End Function

C#:

sealed class Main

{

internal bool blnLoggedIn;

string[] arrUsername = new string[] { "Admin", "Clerk", "Manager" };

string[] arrPassword = new string[] { "password", "password2", "password3" };

public void Login(string username, string passowrd)

{

blnLoggedIn = false;

if (VerifyUsername(username) && VerifyPassword(passowrd))

{

// Find index for username

int userIndex = 0;

for (int loopIndex = 0; loopIndex <= arrUsername.Length - 1; loopIndex++)

{

if (arrUsername[loopIndex] == username)

{

userIndex = Convert.ToInt32(loopIndex);

break;

}

else continue;

}

// Check for password match

if (arrPassword[userIndex] == passowrd)

blnLoggedIn = true;

else

MessageBox.Show("Incorrect password");

}

}

public bool VerifyUsername(string username)

{

for (int positionInUsernameArray = 0; positionInUsernameArray <= arrUsername.Length - 1; positionInUsernameArray++)

{

if (positionInUsernameArray == arrUsername.Length)

break;

if (username == arrUsername[positionInUsernameArray])

return true;

else continue;

}

return false;

}

public bool VerifyPassword(string password)

{

for (int positionInUsernameArray = 0; positionInUsernameArray <= arrPassword.Length - 1; positionInUsernameArray++)

{

if (positionInUsernameArray == arrPassword.Length)

break;

if (password == arrPassword[positionInUsernameArray])

return true;

else continue;

}

return false;

}

}

Step-by-step explanation:

First I created a for loop with a "positionInUsernameArray" and singed it a value of 0. Next I stated while positionInUsernameArraywas less than or equal to arrUsername.Length - 1, positionInUsernameArraywould increment.

Once the base for loop was in place I created two if statements. The first if statement determines if positionInUsernameArray is equal to arrUsername.Length, if so, the for loop breaks and the method returns false. The second if statement determines if the parameter is equal to the position in the arrUsername array, if so, the method would return true, otherwise the for loop will restart.

For the "VerifyPassword" method, I used the same method as "VerifyUsername" just I changed the variable names.

Hope this helped :) If it didn't please let me know what happened so I can fix the code.

Have a good day!