method_chaining.rb

# TODO: Refactor for elegance
def shout_backwards(string)
  # before:
  # all_caps  = string.upcase
  # backwards = all_caps.reverse
  # result    = backwards + "!!!!"

  # return result
  string.upcase.reverse + "!!!!"
end


# FIXME: This is convoluted. Refactor for clarity.

def factors_of(num)
  return [num] if num <= 1
  (2..num - 1).select { |i| x % i == 0 }
end

def squared_primes(array)
  # before: array.find_all{|x| (2..x-1).select(){|i| x % i == 0 }.count == 0 }.map{|p| p*p}
	primes = array.select do |num|
    factors_of(num).count == 0
  end

  primes.map { |num| num ** 2 }
end

# Driver code... don't edit. This should print a bunch of trues.
puts shout_backwards("hello, boot") == "TOOB ,OLLEH!!!"
puts squared_primes([1, 3, 4, 7, 42]) == [1, 9, 49]