Understanding Up Casting and Down Casting (C# reference)

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace Apps

{

    class Doctor1

    {

        protected string name, specialization;

        public Doctor1(string name, string specialization)

        {

            this.name = name;

            this.specialization = specialization;

        }

        public void Print()

        {

            Console.WriteLine(name);

            Console.WriteLine(specialization);

        }

    }

    class ResidentalDoctors1 : Doctor1

    {

        protected int salary;

        public ResidentalDoctors1(string name, string specialization, int salary)

            : base(name, specialization)

        {

            this.salary = salary;

        }

        public new void Print()

        {

            base.Print();

            Console.WriteLine(salary);

        }

        public int GetPay()

        {

            return salary;

        }

    }

    class Consultant1 : Doctor1

    {

        protected int fees, visitNum;

        public Consultant1(string name, string specialization, int fees, int visitNum)

            : base(name, specialization)

        {

            this.fees = fees;

            this.visitNum = visitNum;

        }

        public new void Print()

        {

            base.Print();

            Console.WriteLine(fees);

            Console.WriteLine(visitNum);

        }

        public int GetPay()

        {

            return fees * visitNum;

        }

    }

    class UnderstandingUpDownCasting

    {

        public static void Main()

        {

            //ResidentalDoctors rd = new ResidentalDoctors("Steve", "General", 100);

            //Consultant c = new Consultant("Chitti", "General", 300, 10);

            Doctor1 d = new Consultant1("Chitti", "General", 300, 10);  // Upcasting

            Consultant1 c;

            c = (Consultant1)d; //Downcasting

            //Console.WriteLine(d.GetPay());

            //Console.WriteLine(c.GetPay());

            //rd.Print();

           // c.Print();

        }

    }

}

Program to Copy the file contents from one file to copy part of line in another file throughout

using System;

using System.IO;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace Apps

{

    class FileContentSeperation

    {

        static void Main(string[] args)

        {

            //FileStream fs = new FileStream() 

            StreamReader sfilecontent1 = new StreamReader(@"D:\Practice Applications\Srikanth Tech\File1.txt");

            StreamWriter dfilecontent2 = new StreamWriter(@"D:\Practice Applications\Srikanth Tech\File2.txt");

            string line;

            //Console.WriteLine(line);

            while ((line = sfilecontent1.ReadLine()) != null)

            {

                string[] words = line.Split(',');

                string k = words[1];

                dfilecontent2.Write(k.Trim() + "\r\n");

            }

            sfilecontent1.Close();

            dfilecontent2.Close();

        }

    }

}

Program to find Fibanocci Series (C# reference)

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace Apps

{

    class FibanocciServiesClass

    {

        private int temp;

        public void Fibanocci(int j)

        {

            int a = 1;

            int b = 0;

            if (j == 0)

                Console.WriteLine(0);

            else

            {

                Console.Write(b+"\t");

                Console.Write(a + "\t");

                while (temp < j)

                {

                    temp = a + b;

                    b = a;

                    a = temp;

                    if (temp < j)

                    Console.Write(temp + "\t");

                }

            }

        }

    }

    class FibanocciSeries

    {

        public static void Main()

        {

            Console.WriteLine("Enter a number");

            int i = Int32.Parse(Console.ReadLine());

            FibanocciServiesClass s1 = new FibanocciServiesClass();

            s1.Fibanocci(i);

        }

    }

}

Program to find the Armstrong Number

Consider a number 153. The number has three digits so it becomes the power of each digit. Example: 1^3 + 5^3 + 3^3 = 153. The resultant after calculation is equal to the number itself(Armstrong Number).

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace Apps

{

    class ArmstrongNumberM

    {

        //private int number;

        private int count = 0, tempnum = 0, armstrong = 0,i=0;

        private int[] digits = new int[5];

        public int CountDigits(int num)

        {

            // count digits

            tempnum = num;

            while (tempnum % 10 > 0)

            {

                digits[count] = tempnum % 10;

                tempnum = tempnum / 10;

                count++;

            }

            int s = Evaluator();

            return s;

        }

        public int Evaluator()   // Scope of this method is within countDigits() only so calling this method in it.

        {

            for (int i = 0; i < count; i++)

            {

                armstrong += (int)Math.Pow((double)digits[i], (double)count);

            }

            return armstrong;

        }

    }

    class ArmstrongNumber

    {

        public static void Main()

        {

            Console.WriteLine("Enter the Number to Check for Armstrong or not");

            ArmstrongNumberM s1 = new ArmstrongNumberM();

            //  Console.WriteLine(s1.CountDigits(Int32.Parse(Console.ReadLine())));        // Passing the input to count number of digits method

            int numberentered = int.Parse(Console.ReadLine());

            int returnvalue = s1.CountDigits(numberentered);

            if (numberentered == returnvalue)

            {

                Console.WriteLine("Entered number is Armstrong Number");

            }

            else

                Console.WriteLine("Entered number is NOT Armstrong Number");

        }

    }

}