Hash
class Hash
A Hash is a dictionary-like collection of unique keys and their values. Also called associative arrays, they are similar to Arrays, but where an Array uses integers as its index, a Hash allows you to use any object type.
Hashes enumerate their values in the order that the corresponding keys were inserted.
A Hash can be easily created by using its implicit form:
grades = { "Jane Doe" => 10, "Jim Doe" => 6 }
Hashes allow an alternate syntax for keys that are symbols. Instead of
options =
