A typical use of the
sample method
on Array will look something
like this:
> chars = [('a'..'z'), ('A'..'Z'), ('0'..'9')].map(&:to_a).flatten
> chars.sample(6)
=> ["o", "Z", "X", "i", "8", "Y"]By default, this is using Random (a pseudo-random number generator) to
produce a random sampling of elements from your array.
The longer form of this looks like:
> chars.sample(6, random: Random)
=> ["F", "c", "g", "I", "w", "E"]Or to get reproducible results, you can specify the Random seed:
> chars.sample(6, random: Random.new(123))
=> ["T", "c", "D", "K", "P", "s"]If instead you want a cryptographically random sampling of elements from your
array, you can specify a different random number generator. Such as
SecureRandom.
> require 'securerandom'
=> true
> chars.sample(6, random: SecureRandom)
=> ["3", "C", "o", "i", "K", "4"]The
Array#shuffle
method is another example of a method that can take a random option.