IsPrime in C#

[Kasracer]

This might be useful to someone out there.

This function takes in an integer (32bit but you shouldn't need to worry about that). Then, it uses The Sieve of Eratosthenes method to find out if the number supplied to it is a prime number or not. It's very quick compared to conventional methods.

I was working on this function and found this article to optimize it using the Sieve of Eratosthenes method.

This function may not be that useful to anyone but I thought I would throw it in here.

public static bool IsPrime(Int32 ToBeChecked)
{
    System.Collections.BitArray numbers = new System.Collections.BitArray(ToBeChecked+1, true);
    for (Int32 i = 2; i < ToBeChecked+1; i++)
        if (numbers[[b][/b]i])
        {
            for (Int32 j = i * 2; j < ToBeChecked+1; j += i)
                numbers[j] = false;
            if (numbers[i])
            {
                if (ToBeChecked == i)
                {
                    return true;
                }
            }
        }
    return false;
}