Problems In C-sharp

Prime Number 

 

1. Prime Number Upto 99

 

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace Prime
{
    class Program
    {
        void prime_num(long num)
        {

            bool isPrime = true;
            for (int i = 0; i <= num; i++)
            {
                for (int j = 2; j <= num; j++)
                {
                    if (i != j && i % j == 0)
                    {
                        isPrime = false;
                        break;
                    }
                }
                if (isPrime)
                {
                    Console.WriteLine ( "Prime No:" + i );
                }
                isPrime = true;
            }
        }
        static void Main(string[] args)
        {
            Program p = new Program();
            p.prime_num (99L);
            Console.ReadLine();
        }
    }
} 

 

2.Prime Number Between Two Given Number

 

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace PrimeNumber
{
      class Program
        {

            static void Main(string[] args)
            {

                Console.WriteLine("Enter a No");
                int a = Convert.ToInt32(Console.ReadLine());
                Console.WriteLine("Enter Second No");
                int b = Convert.ToInt32(Console.ReadLine());
                //Add two Number
                int d = a + b;
                Console.WriteLine("{0}", d);

                //Prime  Logic
                bool c = true;
                for (int i = a; i <= b; i++)
                {
                    //Condition For Not a Prime All Non Prime No are Exlcluded Here
                    for (int j = 2; j <= b; j++)
                    {
                        if (i != j && i % j == 0)
                        {
                            c = false;
                            break;
                        }
                    }
                    //Condition For Prime No
                    if (c)
                    {
                        Console.WriteLine("Prime:" + i);
                    }
                    c = true;
                }
                Console.ReadLine();
            }
        }
    }

 

Reverse A Number /String

 

1.Reverse a Number

 

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace Reverse_a_Number
{
    class Program
    {
        static void Main(string[] args)
        {
            int reverse=0,a;
            Console.Write("Enter A Number");
           a = Convert.ToInt32(Console.ReadLine());
            while (a!=0)
            {
               reverse = reverse * 10;
                reverse = reverse + a % 10;
                a = a / 10;
            }
            Console.Write("{0}",reverse);
            Console.ReadLine();
        }
    }
}

2.Reverse a String

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace Reverse_a_String
{
    class Program
    {
        static void Main(string[] args)
        {
            string Str, Revstr = "";
            int Length;

            Console.Write("Enter A String : ");
            Str = Console.ReadLine();

            Length = Str.Length - 1;

            while (Length >= 0)
            {

                Revstr = Revstr + Str[Length];
                Length--;

            }

            Console.WriteLine("Reverse  String  Is  {0}", Revstr);

            Console.ReadLine();
        }
    }
}