using System;
using System.Collections.Generic;
using System.Text;
 
namespace prime
{
    class Program
    {
        static void Main(string[] args)
        {
            int num;
            int result;
            int i, j;
 
            Console.WriteLine("Untill what number u want to show prime number?");
            num = Convert.ToInt32(Console.ReadLine());
            Console.WriteLine("The prime number between o and ur number are:");
            if (num == 2)
                Console.WriteLine("2");
 
            else
            {
 
                Console.WriteLine("2");
                for (i = 3; i <= num; i++)
                {
                    for (j = 2; j <=num / 2; j++)
                    {
                        result = i % j;
                        if (result!=0)
                            Console.WriteLine(i);
 
                     }
 
 
 
 
 
 
 
                }
                Console.ReadLine();
 
            }
        }
    }
}

using System;
using System.Collections.Generic;
using System.Text;
 
namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            bool current = false;
            int j;
 
            Console.WriteLine("Enter any integer");
            int num = Int32.Parse(Console.ReadLine());
 
            for (int i = 2; i <= num; i++)//2 is the first prime number.
                                          //I set i to 2 beacuse it has to print 2 firstly...  
            {
                for (j = 2; j < i; j++)
                {
                    if (i % j == 0)//Controls i is prime number or not...
                    {
                        current = true;
                        break;//breaks for not controlling anymore...
                    }
                }
                if (current == false)
                    Console.Write("{0} ", j);//if i is prime number, print it...
                else
                   current = false;   
            }
 
            Console.ReadLine();
 
 
 
        }
    }
}

using System;
class pnumber
{
public static void Main()
{
int value; // Value Enter By User!
int count,count2; // For inner & outer loop
int prime; // used to check prime number
 
Console.WriteLine("Welcome To My Program\nPlease enter a number to check whether its a prime number or not!");
value=Convert.ToInt32(Console.ReadLine());
for(count=2;count<value;count++) // Outer loop
{
prime = 1; // to set prime value to 1 every time outer loop works
for(count2=2;count2<count;count2++) // Inner loop
{
if(count%count2 == 0) // If Value is divisible..
{
prime = 0; // Set prime to 0
}
}
if(prime==1) // If prime value is 1 then...
Console.WriteLine("{0} Is Prime Number",count); // display count variable
}
}
}

using System;
class g9{
	public static void Main(){
			int num;
			Console.Write("Enter the number till you want Prime Number : ");
			num=Convert.ToInt32(Console.ReadLine());	
			for(int i=2;i<=num;i++){
				if(i<=5 && i!=4){
					Console.Write(i+" ");
				}
					if(i%2!=0 && i%3!=0 && i%5!=0)
					Console.Write(i+" ");
 
			}
		}
}

num = 9:
 
i	j	i%j	output
3	2	1	3
3	3	0	
3	4	3	3
4	2	0	
4	3	1	4
4	4	0	
5	2	1	5
5	3	2	5
5	4	1	5
6	2	0	
6	3	0	
6	4	2	6