Demonstrates how :map can be used on class:Array

array_map.rb

[:a, :b, :c].map {|e| e.to_s }
#=> ['a', 'b', 'c'] # Invoke .to_s on each element and collect these in an array.

[:a, :b, :c].map(&:to_s)
#=> ['a', 'b', 'c'] # The same result obtained in a shorthand fashion.