use this
using System;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace Euler
{
class Program
{
static void Main(string[] args)
{
Prime p = new Prime();
p.ExecutePrimeDirective();
}
}
public class Prime
{
public void ExecutePrimeDirective()
{
string endstring = “”;
while (endstring != “e”)
{
Console.WriteLine("\n What is your uppper limit in searching for prime numbers?");
string numberstring = Console.ReadLine();
int limit = 0;
int test = 0;
if (int.TryParse(numberstring, out test))
limit = test;
else // the else is not required it's left in for clarity
limit = 0;
List<bool> isPrime = new List<bool>();
for (int i = 0; i <= limit; i++)
{
if (DeterminePrime(i))
isPrime.Add(true);
else
isPrime.Add(false);
}
for (int i = 0; i <= limit; i++)
{
Console.WriteLine("isPrime[" + i.ToString()+"] " + isPrime[i]);
}
while (endstring != "e" && endstring != "r")
{
Console.WriteLine("\n Type >>> e <<< and press enter to exit \n Type >>> r <<< to restart and try again");
endstring = Console.ReadLine();
}
}
}
// i just copy pasted this part
public bool DeterminePrime(int number)
{
return (Enumerable.Range(1, number).Where(x => number % x == 0).Count() == 2);
}