RPG - Random Chest Rewards

Greetings,

I want to program a chest that gives a random reward (from a pool from 10 possible rewards). Which is the best way to program this function? If-else? Switch? Array?

And more importantly, how can I define the chance of getting each reward?
For example: The player has 50% of getting Reward1, 3% Reward2, 0.005% Reward3 and so on?

Thanks.

Have an array with all the rewards, and then an array with the chances, that corresponds to the first array.

Then generate a random number, and loop through the chances array, checking if the random number is lower then the chance you have assigned it (Instead of assigning each reward a chance, you need to alot it a chance range somewhere between 0-1, and then order the chances in ascending order.

Example:

rewards = [ new BaconStrip(), new EggMcMuffin(), new AK-47()];
chances = [ 0.5, 0.8, 1];

In this example, getting a bacon strip is a 0.5 chance, getting an egg mcmuffin is 0.3 chance ( 0.8 - 0.5), and getting a brand new AK-47 is a 0.2 chance ( 1 - 0.8).

If you want to get really technical, look into Treasure Classes: Diablo II: Treasure Classes