Random number: 0 or 1 | 易学教程

问题

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";
        }

回答1:

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).

回答2:

If you want 50/50 probability, I suggest:

Random rand = new Random();

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

回答3:

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.

回答4:

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.

回答5:

If not in a tight loop you could use

(DateTime.Now.Millisecond % 2) - double DateTime.Now.Millisecond % (double) 10) / 10

回答6:

A very simple approach could be:

Random random = new Random();
bool result = random.Next(0, 2) != 0;

Then use result for your logic.

来源：https://stackoverflow.com/questions/1493051/random-number-0-or-1

标签

random