One Pitfall when you use C# to generate the Random number

You can have try these two code snippets, see what the different.

for (int i = 0; i < 200; i++)

{

     Random rand = new Random();

     Console.WriteLine(rand.Next());

}

Random rand = new Random();

for (int i = 0; i < 200; i++)

{

    Console.WriteLine(rand.Next()); 

}