Example of a Complex Array of Hashes and how to use Enumerable methods on it

pets.rb

$pets = []

$pets << {
  :name => 'Lallo',
  :nocturnal => false,
  :breed => 'Schnauzer',
  :talents => ['napping', 'rolling over', 'playing dead'],
  :legs => 4
}
$pets << {
  :name => 'Buckminster',
  :nocturnal => false,
  :breed => 'Scottish Fold Kitty',
  :talents => ['napping', 'ignoring humans', 'singing'],
  :legs => 4
}
$pets << {
  :name => 'Roro',
  :nocturnal => true,
  :breed => 'African Grey Parrot',
  :talents => ['mimicry', 'singing'],
  :legs => 2
}
$pets << {
  :name => 'Little Jade',
  :nocturnal => true,
  :breed => 'Box Turtle',
  :talents => ['swimming', 'napping'],
  :legs => 4
}
$pets << {
  :name => 'Cometa',
  :nocturnal => false,
  :breed => 'Slug',
  :talents => ['ignoring humans', 'being squishy'],
  :legs => 0
}

# 2 different ways to find how many of our pets are nocturnal
puts "Number of Noctural Pets: #{$pets.reject{|p| p[:nocturnal] == false}.count}"
puts "Number of Noctural Pets: #{$pets.select{|p| p[:nocturnal] == true}.count}"

Here are the Rubydocs for Enumerables - http://ruby-doc.org/core-2.0.0/Enumerable.html