Demonstrates how to form Hashes from Arrays in Ruby.

hashes_and_ararys.rb

{:a => 'alpha'}.to_a
#=> [[:a, "alpha"]] # Notice the nested array

Hash[:a => 'alpha']
#=> {:a => 'alpha'}

Hash[[:a => 'alpha']]
#=> {} # Doesn't work with a nested array.

Hash[[[:a => 'alpha']]]
#=> {:a => 'alpha'} # Works with a doubly nested array.

# Notice that this is NOT a treble nested array.
# The outermost [] is the method notation that class:Hash accepts.
# So, it is a doubly nested array.