Generate non-repeating random numbers in Ruby

Question

I want to generates a sequence of unique random number between 100 and 999. I want to make sure that no numbers are generated twice, to ensure that each number is unique. Here is what I came up with. It does not work. When i run it, the screen is just blank. Can anyone help me?

products = {}

def random_key(products)

  rand_key = rand(900) + 100

  while products.has_key?(rand_key)

    rand_key = rand(900) + 100

  end

end

puts random_key(products)

Answer 1

a = (100..999).to_a.shuffle 

then every time you need a new id

new_id = a.pop

This guarantees that numbers are never reused. Of course, you'll have problems when you run out of elements on the array.