C#

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

namespace Ch11Ex03yield
{
    public class Primes 
    {
        private long min;
        public  long max;

        public Primes()
            : this(2, 100)
        {
        }

        public Primes(long i, long j)
        {
            if (i < 2)
            {
                min = 2;
            }
            min = i;
            max = j;
        }
        public IEnumerator GetEnumerator()
        {
            for (long possiblePrime = min; possiblePrime <= max; possiblePrime++)
            {
                bool isPrime = true;
                for (long possibleFactor = 2; possibleFactor <=
                    (long)Math.Floor(Math.Sqrt(possiblePrime)); possibleFactor++)
                {
                    long remainderAfterDivision = possiblePrime % possibleFactor;
                    if (remainderAfterDivision == 0)
                    {
                        isPrime = false;
                        break;
                    }
                }
                if (isPrime)
                {
                    yield return possiblePrime;
                }
            }
        }
    }
                        
    class Program
    {
        static void Main(string[] args)
        {
            Primes myPrimes = new Primes(2,1000);
            foreach (long i in myPrimes)
                Console.Write("{0}{1} ",i,
                    (i==myPrimes.max )?".":",");
            
            Console.ReadKey();
        }
    }
}