How to use Cursor AI to Generate CSharp(C#) Code

using System;
using System.Text.RegularExpressions;

namespace CSharpExample
{
public class UserLogin
{
private string _username;
private string _password;
private bool _isLoggedIn;

public UserLogin()
{
_isLoggedIn = false;
}

public bool Register(string username, string password)
{
if (!ValidateUsername(username))
{
throw new ArgumentException("Username must be between 3-20 characters and contain only letters and numbers");
}

if (!ValidatePassword(password))
{
throw new ArgumentException("Password must be at least 8 characters long and contain at least one number and one special character");
}

_username = username;
_password = password;
return true;
}

public bool Login(string username, string password)
{
if (_username == null || _password == null)
{
throw new InvalidOperationException("User must be registered before logging in");
}

if (username == _username && password == _password)
{
_isLoggedIn = true;
return true;
}

return false;
}

public void Logout()
{
_isLoggedIn = false;
}

public bool IsLoggedIn => _isLoggedIn;

private bool ValidateUsername(string username)
{
// Username must be 3-20 characters long and contain only letters and numbers
return Regex.IsMatch(username, @"^[a-zA-Z0-9]{3,20}$");
}

private bool ValidatePassword(string password)
{
// Password must be at least 8 characters long and contain at least one number and one special character
return password.Length >= 8 &&
Regex.IsMatch(password, @"[0-9]") &&
Regex.IsMatch(password, @"[!@#$%^&*(),.?""':{}|<>]");
}
}
}

Now, let's modify the Program.cs to demonstrate the usage of the UserLogin class:

using System;

namespace CSharpExample
{
class Program
{
static void Main(string[] args)
{
Console.WriteLine("Welcome to C# Example!");

// Demonstrate basic C# features
var calculator = new Calculator();

Console.WriteLine("\nBasic Calculator Operations:");
Console.WriteLine($"5 + 3 = {calculator.Add(5, 3)}");
Console.WriteLine($"10 - 4 = {calculator.Subtract(10, 4)}");
Console.WriteLine($"6 * 7 = {calculator.Multiply(6, 7)}");
Console.WriteLine($"15 / 3 = {calculator.Divide(15, 3)}");

// Demonstrate string interpolation and DateTime
Console.WriteLine($"\nCurrent date and time: {DateTime.Now}");

// Demonstrate exception handling
try
{
Console.WriteLine($"\nDivision by zero test: {calculator.Divide(5, 0)}");
}
catch (DivideByZeroException ex)
{
Console.WriteLine($"Error: {ex.Message}");
}

// Demonstrate UserLogin functionality
Console.WriteLine("\nUser Login Demonstration:");
var userLogin = new UserLogin();

try
{
// Try to register with invalid credentials
Console.WriteLine("\nAttempting to register with invalid credentials...");
userLogin.Register("ab", "password"); // Too short username
}
catch (ArgumentException ex)
{
Console.WriteLine($"Registration failed: {ex.Message}");
}

try
{
// Register with valid credentials
Console.WriteLine("\nAttempting to register with valid credentials...");
userLogin.Register("john123", "Password123!");
Console.WriteLine("Registration successful!");

// Try to login with wrong password
Console.WriteLine("\nAttempting to login with wrong password...");
if (!userLogin.Login("john123", "wrongpass"))
{
Console.WriteLine("Login failed: Invalid credentials");
}

// Login with correct credentials
Console.WriteLine("\nAttempting to login with correct credentials...");
if (userLogin.Login("john123", "Password123!"))
{
Console.WriteLine("Login successful!");
Console.WriteLine($"User is logged in: {userLogin.IsLoggedIn}");

// Logout
userLogin.Logout();
Console.WriteLine($"After logout, user is logged in: {userLogin.IsLoggedIn}");
}
}
catch (Exception ex)
{
Console.WriteLine($"Error: {ex.Message}");
}

Console.WriteLine("\nPress any key to exit...");
Console.ReadKey();
}
}

public class Calculator
{
public int Add(int a, int b) => a + b;
public int Subtract(int a, int b) => a - b;
public int Multiply(int a, int b) => a * b;
public int Divide(int a, int b)
{
if (b == 0)
throw new DivideByZeroException("Cannot divide by zero!");
return a / b;
}
}
}