Random Array of numbers

Question

Hi there I would like to figure out how to shorten a piece of code. I have it working the way I want it to work however I know it can be simplified I just can't figure out how. I want to make a do while loop that checks to see if the array is empty. int draw; int[] balls = new int[5]; int size = balls.Length; int count = 0; Random rdmn = new Random(); for (int i = 0; i { draw = rdmn.Next(50); if (!balls.Contains(draw)) { balls[count] = draw; count++; } else { size++; } } foreach (int n in balls) { Console.WriteLine(n); } Right now I am adding to the size of the loop if the number is not unique. However if I can put in a do while loop then I can get rid of int size etc. Thank for your time.

Vulpes · Answer

It would be possible to do it like this: int draw; int[] balls = new int[5]; int size = balls.Length; // all zero by default for(int i = 0; i Random rdmn = new Random(); for(int i = 0; i { while(true) { draw = rdmn.Next(50); // random n umber between 0 and 49 if (!balls.Contains(draw)) { balls[i] = draw; break; } } } foreach (int n in balls) { Console.WriteLine(n); } Notice that you have a small problem at the moment in that all the elements of balls are zero to start with and the random number could conceivably be zero as well. I've fixed it by re-initializing all the elements of the array to -1.

Michael Malcolm · Answer

This has been very helpful thank you very much.

Vulpes · Answer

Yes when you create an array of ints then it's automatically filled with zero which is the default value of an int. Similarly an array of bools would be filled with 'false' an array of chars with '\0' and an array of strings (or any other reference type) with null. Incidentally it's possible to create an empty array by setting its length to 0: int[] empty = new int[0]; but remembering that you can't change an array's length once you've created it this is only of use in special situations.

Michael Malcolm · Answer

Ah so what you are saying is when I create the array it is automatically filled with zero rather than null. So if I make the values -1 then I check to see if there is -1 and this would work the same as if array is empty then do. My understanding of Array's isn't very strong. That is why I asked for help. I thought that I could: while (array is empty) generate random number if number isn't in the array add it Thanks for your time.