Notes

/*using System;
using System.Text;
using System.Threading.Tasks;

namespace calculator_c_sharp
{
class Program
{
static void Main(string[] args)
{
string value;
do
{
int res;
Console.Write("Enter first number:");
int num1 = Convert.ToInt32(Console.ReadLine());
Console.Write("Enter second number:");
int num2 = Convert.ToInt32(Console.ReadLine());
Console.Write("Enter symbol(/,+,-,*):");
string symbol = Console.ReadLine();

switch (symbol)
{
case "+":
res = num1 + num2;
Console.WriteLine("Addition:" + res);
break;
case "-":
res = num1 - num2;
Console.WriteLine("Subtraction:" + res);
break;
case "*":
res = num1 * num2;
Console.WriteLine("Multiplication:" + res);
break;
case "/":
res = num1 / num2;
Console.WriteLine("Division:" + res);
break;
default:
Console.WriteLine("Wrong input");
break;
}
Console.ReadLine();
Console.Write("Do you want to continue(y/n):");
value = Console.ReadLine();
}
while (value=="y" || value=="Y");
}
}

}*/
//==================================================
/*using System;

class Program
{
static void Greatings()
{
// Ask the user to enter their name
Console.Write("Please enter your name: ");

// Read the name from the console
string name = Console.ReadLine();

// Print out the name
Console.WriteLine("Hello, " + name + "!");
}
}*/

//=====================================================
// See https://aka.ms/new-console-template for more information
/*using System.Reflection.Metadata.Ecma335;

Console.WriteLine("Hello, World!");

System.Console.WriteLine();
System.Console.ReadLine();

Greatings( name, age);
*/

//=============================
/*
System.Console.WriteLine("Please insert your name: ");
var ner = Console.ReadLine();

System.Console.WriteLine("Please insert your age: ");
var nas = Console.ReadLine();

Greatings(ner, Convert.ToInt32(nas));


void Greatings(String name, int age) {
System.Console.WriteLine("Hello, " + name.Contains("bbi"));//Contains dotor bga string bga esehiig shalgaj tru bolon false aar hariu ugnu
System.Console.WriteLine("You are " + age+ " years old!");

*/

//-==================================================

/*
using System;
using System.IO;
using Newtonsoft.Json;
using System.Security.Cryptography;
using System.Text;

class Program
{
private static readonly string filePath = "/home/lab-209/Project 1/week2cs4b/user.json";

static void Main(string[] args)
{
Console.WriteLine("1. Register");
Console.WriteLine("2. Login");
var choice = Console.ReadLine();
switch (choice)
{
case "1":
Register();
break;
case "2":
Login();
break;
default:
Console.WriteLine("Invalid choice.");
break;
}
}
static void Register(){
Console.WriteLine("Enter your name: ");
var username = Console.ReadLine();
Console.WriteLine("Enter your password: ");
var password = Console.ReadLine();
string hashedPassword = HashPassword(password);//hashpassword ni password iig nuutsladag
User user = new User{
Username = username,
Password = hashedPassword
};
try{
string json = JsonConvert.SerializeObject(user, Formatting.Indented);
File.WriteAllText(filePath, json);
Console.WriteLine("Successfully registered...");
}
catch (IOException e){
Console.WriteLine("Error writing to file: " + e.Message);
}
}

static void Login(){
Console.WriteLine("Enter your username: ");
string inputName = Console.ReadLine();
Console.WriteLine("Enter your password: ");
string inputPwd = Console.ReadLine();
try{
if (!File.Exists(filePath)){
Console.WriteLine("User data not found.");
return;
}
string json = File.ReadAllText(filePath);
User storedUser = JsonConvert.DeserializeObject<User>(json);
if (storedUser != null && storedUser.Username == inputName && VerifyPassword(inputPwd, storedUser.Password)){
Console.WriteLine("Logging in SUCCESSFULY");
}else{
Console.WriteLine("Login failed.");
}
}
catch (IOException e){
Console.WriteLine("Error reading from file: " + e.Message);
}
}
static string HashPassword(string password){
using (var sha256 = SHA256.Create()){
byte[] bytes = sha256.ComputeHash(Encoding.UTF8.GetBytes(password));
StringBuilder sb = new StringBuilder();
foreach (byte b in bytes){
sb.Append(b.ToString("x2"));
}
return sb.ToString();
}
}
static bool VerifyPassword(string inputPassword, string storedHashedPassword)
{
string hashedInputPassword = HashPassword(inputPassword);
return hashedInputPassword == storedHashedPassword;
}

class User
{
public string Username { get; set; }
public string Password { get; set; }
}
}

*/