Why is the System.Random class not static?

Question

When you use the System.Random class, you must make an instance of it. Why is it not static? Because if I want a random number between 0 and 9, I can use the static method, System.Random.Next(int, int):

int ourRandomNumber = Random.Next(0,9);

So why isn't the class just static?

Answer 1

You wouldn't be able to use different seeds if it were static - the Random instance keeps track of that state. By default Random uses the current time as seed, but re-using a particular seed (i.e. new Random(42)) allows you to exactly repeat the sequence of random numbers - they will always be the same for the same seed. This aspect is very important in some applications. For example, Minecraft.