class Range: A \Range object represents a collection of values that are between given begin and end values. literals.| docs.ruby-lang.org
module Enumerable: Enumerable@Methods+for+Iterating] - {And more. tt>, +false+ otherwise.| docs.ruby-lang.org
class Array: en. wikipedia.| docs.ruby-lang.org
class Object: Object is the default root of all Ruby objects. Object inherits from BasicObject which allows creating alternate object hierarchies.| docs.ruby-lang.org
class Hash: A +Hash+ maps each of its unique keys to a specific value. An Array index is always an Integer.| docs.ruby-lang.org