instance method any?

Returns true if the collection is not empty.

class Person < ActiveRecord::Base
  has_many :pets
end

person.pets.count # => 0
person.pets.any?  # => false

person.pets << Pet.new(name: 'Snoop')
person.pets.count # => 1
person.pets.any?  # => true

Calling it without a block when the collection is not yet loaded is equivalent to collection.exists?. If you’re going to load the collection anyway, it is better to call collection.load.any? to avoid an extra query.

You can also pass a block to define criteria. The behavior is the same, it returns true if the collection based on the criteria is not empty.

person.pets
# => [#<Pet name: "Snoop", group: "dogs">]

person.pets.any? do |pet|
  pet.group == 'cats'
end
# => false

person.pets.any? do |pet|
  pet.group == 'dogs'
end
# => true