Thread: Display Prime Number in C#

Hi. I am first year MCA Student. I am learning C# programming language. Right now I have little bit knowledge of C#. I want to write a program for to find a prime number. I tried different way but none of them worked out. Any help would be highly appreciated. Thanks in advanced.

Refer following program to display Prime Number program in C# :

Code:

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

namespace ConsoleApplication16
{
    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:" + i );
                }
                isPrime = true;
            }
        }



        static void Main(string[] args)
        {
            Program p = new Program();
            p.prime_num (999999999999999L);
            Console.ReadLine();

        }
    }
}

Try out this code, when you run this program you get the prime number as an output result:

Code:

int counter;
int counter2;
float ansFloat;
int ansInt;
float check;
check = 1;
for (counter = numStart; counter <= numEnd; counter++)
{
for (counter2 = 2; counter2 < counter; counter2++)
{
ansFloat = counter / counter2;
ansInt = counter / counter2;
check = ansInt / ansFloat;
while (check == 1)
{
// Don't do anything.
}
}