instance method `slice`

Ruby on Rails 4.1.16

Since v2.3.18 Last seen in v5.2.8.1

Available in: v2.3.18 v3.0.20 v3.1.12 v3.2.22.5 v4.0.13 v4.1.16 v4.2.9 v5.2.8.1

Compare with:

slice(*keys)

Slice a hash to include only the given keys. This is useful for limiting an options hash to valid keys before passing to a method:

def search(criteria = {})
  criteria.assert_valid_keys(:mass, :velocity, :time)
end

search(options.slice(:mass, :velocity, :time))

If you have an array of keys you want to limit to, you should splat them:

valid_keys = [:mass, :velocity, :time]
search(options.slice(*valid_keys))

Parameters

keys rest

Source

# File activesupport/lib/active_support/core_ext/hash/slice.rb, line 15
  def slice(*keys)
    keys.map! { |key| convert_key(key) } if respond_to?(:convert_key, true)
    keys.each_with_object(self.class.new) { |k, hash| hash[k] = self[k] if has_key?(k) }
  end

Defined in activesupport/lib/active_support/core_ext/hash/slice.rb line 15 · View on GitHub · Improve this page · Find usages on GitHub

Defined in Hash

Signature

Parameters