Program2.cs

using System;
using System.Collections.Generic;
delegate void Mydelegate(String Name);
delegate void Heatwave(String city, int temp);
delegate void lowbal(int acno, int bal);
class Program
{
    static void Main()
    {
        //Dictionary<int,string> students = new Dictionary<int,string>();
        //students.Add(1, "xyz");
        //students.Add(2, "abc");
        //foreach (var student in students)
        //{
        //    Console.WriteLine($"{student.Key},{student.Value}");
        //}





        ////generate a dictionary for 3 students having rolno and name, ask the user to enter name of n student and your 
        ////program should show the details if the student exists

        //Dictionary<int, string> students = new Dictionary<int, string>();
        //students.Add(1, "xyz");
        //students.Add(2, "abc");
        //students.Add(3, "pqr");

        //String n=Console.ReadLine();
        //int f = 0;

        //foreach (var student in students)
        //{
        //    if (n == student.Value)
        //    {
        //        Console.WriteLine($"{student.Key},{student.Value}");
        //        f = 1;
        //    }

        //}
        //if (f == 0) Console.WriteLine("not found");




        //Car c1 = new Car(1111,"BMW","Jetshree");
        //c1.display();





        //Bank b = new Bank("abc", 1, 10000);
        //Console.WriteLine(b.add(10000));
        //Console.WriteLine(b.withdraw(200));





        //Overloading o1=new Overloading();
        //o1.add(1, 2);
        //o1.add(3, 4,3);





        //Animal a=new Animal();
        //a.speak();
        //Animal b = new Dog();
        //b.speak();
        //Animal c = new Bulldog();
        //c.speak();




        //Animals a = new Dogs();
        //a.speak();
        //a.eat();




        //Mydelegate del = GreetEnglish;
        //del += GreetHindi;
        //del += GreetGuj;
        //del("abc");
           




        //WeatherStorm w = new WeatherStorm("Ahmedabad", 45);
        //w.handler += OnAlert;
        //w.updatetemp(48);





        BankAccount b = new BankAccount(1, 5000);
        b.lh += Alert;
        b.withdraw(4500);


    }
    public static void OnAlert(String city, int temp) 
    {
        Console.WriteLine("alert");
    }
    public static void Alert(int acno, int temp)
    {
        Console.WriteLine("low balance");
    }



    // delegate and events
    // develop an approach delegate to greet user (in 3 different languages)

    static void GreetEnglish(String name) 
    {
        Console.WriteLine("Hello " + name);
    }
    static void GreetHindi(String name)
    {
        Console.WriteLine("Hello (hindi)" + name);
    }
    static void GreetGuj(String name)
    {
        Console.WriteLine("Hello (Guj)" + name);
    }
}


//create a class for car, assign 2 objects to it. Attributes : car no., car brand and customer name. consider action as 
//all the details to be printed
class Car
{
    public int carno;
    public String brand;
    public String customer;
    public Car(int no, String br, String cus)
    {
        carno = no;
        brand = br;
        customer = cus;
    }

    public void display() {
        Console.WriteLine(carno);
        Console.WriteLine(brand);
        Console.WriteLine(customer);
    }

}

// consider class of bank account in which you have details like account holder name, acc no and balance
// you want to provide 2 options: add money or withdraw 
// after any action is done show acc no, balance and customer name

class Bank {
    public String cust;
    public int accno;
    public int balance;

    public Bank(String c, int a, int b)
    {
        cust= c;
        accno= a;
        balance= b;
    }

    public int add(int i) { 
        balance += i;
        return balance;
    }
    public int withdraw(int w) {
        if (w < balance) balance = balance - w;
        else Console.WriteLine("not enough balance");
        return balance;
    }
}

// overloading

class Overloading { 
    public void add(int a, int b, int c)
    {
        Console.WriteLine(a + b + c);
    }
    public void add(int a, int b)
    {
        Console.WriteLine(a + b);
    }
}


// overriding => virtual, override, sealed override

class Animal
{
    public virtual void speak() {
        Console.WriteLine("Animal makes sound");
    }
}
class Dog : Animal 
{
    public override void speak() // writing sealed gives error when dog is parent
    {
        Console.WriteLine("Dog barks");
    }
}
class Bulldog : Dog
{
    public override void speak()
    {
        Console.WriteLine("Bulldog barks");
    }
}


// abstract => must be in child class also

abstract class Animals
{
    public abstract void speak();
    public void eat() => Console.WriteLine("Eating");
}
class Dogs : Animals
{
    public override void speak() // writing sealed gives error when dog is parent
    {
        Console.WriteLine("Dog barks");
    }
}



//create delegate and events , class is weather storm with field city and temp
//methods : update temp, define del and ev for heatwave method, raise the event if temp>40
// in main create weather storm object, subscribe to the event an ddisplay a warning msg whne triggered


class WeatherStorm 
{
    public String city;
    public int temp;
    public event Heatwave handler;

    public WeatherStorm(String City, int Temp)
    {
        city = City;
        temp = Temp;
    }

    public void updatetemp(int temperature)
    {
        temp = temperature;
        if (temp > 43) 
        {
            handler ?. Invoke(city, temperature);
        }

    }
}

/* 
 create a class bankaccount. attr: acno and balance, there is a method withdraw that decreases the balance
define del and event lowbalance alert
the event should be raised when the balance goes below 1000 event trigger
in the withdraw method after the deduction check if the balance is < 1000 if true trigger the low balance 
alert and pass the current balance in main part create bankaccount obj with initial bal 5000.
perform certain withdrwals and raise bal trigger.
 */

class BankAccount
{
    public int acno;
    public int bal;
    public event lowbal lh;

    public BankAccount(int a, int b)
    {
        acno = a;
        bal = b;
    }

    public void withdraw(int b)
    {
        bal -= b;
        if (bal < 1000) { 
            lh?.Invoke(acno, bal);
        }
    }

}