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Secure Login Validation with Username and Password in C#

This C# program implements a basic authentication system that continuously prompts the user to enter a username and password until they match the correct credentials.

The program follows these steps:
1. It prompts the user to enter a username.
2. It prompts the user to enter a password.
3. If the entered credentials are incorrect, it displays an error message and asks the user to try again.
4. The process repeats indefinitely until the user enters the correct username "username" and password "password".
5. Once the correct credentials are provided, the program grants access and terminates.

This exercise is a great introduction to user authentication logic and loop structures in C#.



Group

C# Basic Data Types Overview

Objective

Write a C# program to ask the user for their username and password (both should be strings) and repeat it as many times as necessary until the entered name is "username" and the password is "password".

Example C# Exercise

 Copy C# Code 
using System;

class Program
{
    static void Main()
    {
        string correctUsername = "username"; // Expected username
        string correctPassword = "password"; // Expected password

        string enteredUsername, enteredPassword;

        do
        {
            // Prompt the user for a username
            Console.Write("Enter your username: ");
            enteredUsername = Console.ReadLine();

            // Prompt the user for a password
            Console.Write("Enter your password: ");
            enteredPassword = Console.ReadLine();

            // Check if the credentials are correct
            if (enteredUsername != correctUsername || enteredPassword != correctPassword)
            {
                Console.WriteLine("Incorrect username or password. Please try again.\n");
            }

        } while (enteredUsername != correctUsername || enteredPassword != correctPassword);

        // Successful login message
        Console.WriteLine("\nAccess granted. Welcome!");
    }
}

 Output

//Example 1 (Incorrect Attempt Followed by Success):
Enter your username: admin
Enter your password: 1234
Incorrect username or password. Please try again.

Enter your username: user
Enter your password: pass
Incorrect username or password. Please try again.

Enter your username: username
Enter your password: password

Access granted. Welcome!

//Example 2 (Success on First Attempt):
Enter your username: username
Enter your password: password

Access granted. Welcome!

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