Choosing a random string in C# for WP7

Question

I am making a WP7 app that, when a user taps an image, randomly decides what they will get.

Right now, I have this code:

string firstdoor = "";

string seconddoor = "";

string thirddoor = "";

and

string prize1 = "vacation to Hawaii with all expenses covered";

string prize2 = "used glue stick";

string prize3 = "pile of dog dung";

string prize3 = "vacation to Europe with all expenses covered";

string prize3 = "million dollars";

string prize3 = "blank CD";

string prize3 = "temporary tattoo";

string prize3 = "nickel";

string prize3 = "dime";

and

What I want to do is randomly assign the door s to the prize s.

For instance, when the user taps the image, dime is assigned to thirddoor , nickel is assigned to firstdoor, and million dollars is assigned to secondoor .

Answer 1

Here are the steps that seem to make the most sense to me (not going to write all the code for you):

1. Put all prize strings in an array.

2. Generate three random numbers between 0 and the maximum number of prizes.

3. Assign each door the prize from the prize array with each of the random numbers.

4. ...

5. Profit!

Edit

Actually, here's a little bit of code to help out:

var randomGenerator = new Random();

string[] prizes = { "vacation to Hawaii with all expenses covered",
                    "used glue stick",
                    "pile of dog dung",
                    "vacation to Europe with all expenses covered" };

string firstDoor = prizes[randomGenerator.Next(prizes.Length)];
string secondDoor = prizes[randomGenerator.Next(prizes.Length)];
string thirdDoor = prizes[randomGenerator.Next(prizes.Length)];

Answer 2

On the assumption that you don't want to repeat any of the prizes the solution is a little more complicated, but you can bring some Linq and a little trick with Random into play:

    var prizes = new string[] {
        "vacation to Hawaii with all expenses covered",
        "used glue stick",
        // etc
        "dime"            
    };

    var rand = new Random();

    var result = (from prize in prizes
                  orderby rand.NextDouble()
                  select prize).Take(3).ToArray();

Answer 3

Justin, your answer is fine but might result in 2 doors having the same prize. I believe this might be better:

string[] prizes = new string[]
        {
            "Prize 1",
            "Prize 2",
            "Prize 3",
            "Prize 4",
            "Prize 5"
        };

        Random r = new Random();
        var choices = prizes.OrderBy(x => r.Next()).Take(3).ToArray();

        string firstDoor = choices[0];
        string secondDoor = choices[1];
        string thirdDoor = choices[2];