Enumerable and Ruby Comparable

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I read the Ruby documentation about the modules Enumerable and Comparable, but I didn’t really understand what they do. Could someone give me some examples where I use them in my classes?

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DRT: the Enumerable is responsible for seeking and ordering and the Comparable by setting out the ordination rules (>, <, >=, <=) of the items of the enumeration.

The relationship between the Enumerable and the Comparable is implicit. Let’s go to the concepts:

The mixin Enumerable is used in collections that need search and sort methods. The class Array, Ruby, for example, extends the module Enumerable.

[:debito, :credito, :boleto].include? :dinheiro
=> false

In the above example, I used the method Enumerable#include?, available through the class Array.

In addition to the ability to search, the Enumerable also sorts. The problem is: to sort, one needs comparators as larger, smaller and equal.

The ordering methods of Enumerable need the collection items to extend or implement the Comparable, or has a name method <=> and return 1, 0 or -1.

So that’s how you can do this kind of operation:

nomes = ['João', 'Maria', 'Carlos']
nomes.max
=> 'Maria'

  • Would you have an example of how to implement in my classes? .

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