A class which allows both internal and external iteration.| docs.ruby-lang.org
An instance of class IO (commonly called a stream) represents an input/output stream in the underlying operating system. Class IO is the basis for input and output in Ruby.| docs.ruby-lang.org
Public Instance Methods| docs.ruby-lang.org
An Array is an ordered, integer-indexed collection of objects, called elements. Any object (even another array) may be an array element, and an array can contain objects of different types.| docs.ruby-lang.org