Random number: 0 or 1

Question

Am I looking too far to see something as simple as pick a number: 0 or 1?

  Random rand = new Random();

  if (rand.NextDouble() == 0)
  {
   lnkEvents.CssClass = "selected";
  }
  else
  {
   lnkNews.CssClass = "selected";
  }

Answer 1

If you want 50/50 probability, I suggest:

            Random rand = new Random();

            if (rand.NextDouble() >= 0.5)
            {
                    lnkEvents.CssClass = "selected";
            }
            else
            {
                    lnkNews.CssClass = "selected";
            }

Answer 2

Random.NextDouble() will select any double number from 0 but less than 1.0. Most of these numbers are not zero, so your distribution will not be as even as you expect.

Answer 3

            Random rand = new Random();

            if (rand.Next(0, 2) == 0)
            {
                    lnkEvents.CssClass = "selected";
            }
            else
            {
                    lnkNews.CssClass = "selected";
            }

Random.Next picks a random integer between the lower bound (inclusive) and the upper bound (exclusive).

Answer 4

It seems like what you're wanting to do (choose between two values) is more clearly expressed by using the Next method, instead of the NextDouble method.

const int ExclusiveUpperBound = 2;
if (new Random().Next(ExclusiveUpperBound) == 0)

The value produced is "greater than or equal to zero, and less than" ExclusiveUpperBound.