CODEWITHSUNDEEP
c#arraysvisual-studio-2012
Dan Butcher
Dan Butcher

Reputation: 7

Random Values for an Array?

I'm looking for some help with my array. to put it in context im trying to create a console application that randomly generates a 4-digit code for the user to guess.

to do this I need an array of [3] and they need to have random numbers assigned to it.

        int[] secretCode = new int[3];

        secretCode[0] = 
        secretCode[1] = 
        secretCode[2] = 
        secretCode[3] =

My concern is what would i put here to make them generate random numbers?

thank you for your help in advance.

Upvotes: 1

Views: 77

Answers (1)

Eric J.
Eric J.

Reputation: 150108

You can use Linq and the Random class

Random rnd = new Random();
int[] secretCode = 
    Enumerable.Repeat(0, 4).Select(i => rnd.Next(1000, 10000)).ToArray();

or more traditionally

int SIZE = 4;
Random rnd = new Random();
int[] secretCode = new int[SIZE]; 
for (int i = 0; i < SIZE; i++)
{
    secretCode[i] = rnd.Next(1000, 10000);
}

Note that there is a possibility of creating the same code more than once. The solution assumes you want something in the range 1000..9999 (10000 is an exclusive upper bound) since the code is to be 4 digits. If you would also allow smaller numbers, just adjust the Select portion.

As a side note, do not create a new instance of Random inside the select, as it would likely be reseeded to the same seed, based on the system time, resulting in the same "random" number over and over. Also Random is fast, but not cryptographically strong. If you need cryptographically valid randomness use RNGCryptoServiceProvider in place of Random.

Upvotes: 2

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