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Instance Public methods
compact_blank() Link
Returns a new Array
without the blank items. Uses Object#blank?
for determining if an item is blank.
[1, "", nil, 2, " ", [], {}, false, true].compact_blank
# => [1, 2, true]
Set.new([nil, "", 1, false]).compact_blank
# => [1]
When called on a Hash
, returns a new Hash
without the blank values.
{ a: "", b: 1, c: nil, d: [], e: false, f: true }.compact_blank
# => { b: 1, f: true }
exclude?(object) Link
The negative of the Enumerable#include?
. Returns true
if the collection does not include the object.
excluding(*elements) Link
Returns a copy of the enumerable excluding the specified elements.
["David", "Rafael", "Aaron", "Todd"].excluding "Aaron", "Todd"
# => ["David", "Rafael"]
["David", "Rafael", "Aaron", "Todd"].excluding %w[ Aaron Todd ]
# => ["David", "Rafael"]
{foo: 1, bar: 2, baz: 3}.excluding :bar
# => {foo: 1, baz: 3}
in_order_of(key, series, filter: true) Link
Returns a new Array
where the order has been set to that provided in the series
, based on the key
of the objects in the original enumerable.
[ Person.find(5), Person.find(3), Person.find(1) ].in_order_of(:id, [ 1, 5, 3 ])
# => [ Person.find(1), Person.find(5), Person.find(3) ]
If the series
include keys that have no corresponding element in the Enumerable
, these are ignored. If the Enumerable
has additional elements that aren’t named in the series
, these are not included in the result, unless the filter
option is set to false
.
including(*elements) Link
Returns a new array that includes the passed elements.
[ 1, 2, 3 ].including(4, 5)
# => [ 1, 2, 3, 4, 5 ]
["David", "Rafael"].including %w[ Aaron Todd ]
# => ["David", "Rafael", "Aaron", "Todd"]
index_by() Link
Convert an enumerable to a hash, using the block result as the key and the element as the value.
people.index_by(&:login)
# => { "nextangle" => <Person ...>, "chade-" => <Person ...>, ...}
people.index_by { |person| "#{person.first_name} #{person.last_name}" }
# => { "Chade- Fowlersburg-e" => <Person ...>, "David Heinemeier Hansson" => <Person ...>, ...}
index_with(default = (no_default = true)) Link
Convert an enumerable to a hash, using the element as the key and the block result as the value.
post = Post.new(title: "hey there", body: "what's up?")
%i( title body ).index_with { |attr_name| post.public_send(attr_name) }
# => { title: "hey there", body: "what's up?" }
If an argument is passed instead of a block, it will be used as the value for all elements:
%i( created_at updated_at ).index_with(Time.now)
# => { created_at: 2020-03-09 22:31:47, updated_at: 2020-03-09 22:31:47 }
# File activesupport/lib/active_support/core_ext/enumerable.rb, line 75 def index_with(default = (no_default = true)) if block_given? result = {} each { |elem| result[elem] = yield(elem) } result elsif no_default to_enum(:index_with) { size if respond_to?(:size) } else result = {} each { |elem| result[elem] = default } result end end
many?() Link
Returns true
if the enumerable has more than 1 element. Functionally equivalent to enum.to_a.size > 1
. Can be called with a block too, much like any?, so people.many? { |p| p.age > 26 }
returns true
if more than one person is over 26.
maximum(key) Link
Calculates the maximum from the extracted elements.
payments = [Payment.new(5), Payment.new(15), Payment.new(10)]
payments.maximum(:price) # => 15
minimum(key) Link
Calculates the minimum from the extracted elements.
payments = [Payment.new(5), Payment.new(15), Payment.new(10)]
payments.minimum(:price) # => 5
pick(*keys) Link
Extract the given key from the first element in the enumerable.
[{ name: "David" }, { name: "Rafael" }, { name: "Aaron" }].pick(:name)
# => "David"
[{ id: 1, name: "David" }, { id: 2, name: "Rafael" }].pick(:id, :name)
# => [1, "David"]
pluck(*keys) Link
Extract the given key from each element in the enumerable.
[{ name: "David" }, { name: "Rafael" }, { name: "Aaron" }].pluck(:name)
# => ["David", "Rafael", "Aaron"]
[{ id: 1, name: "David" }, { id: 2, name: "Rafael" }].pluck(:id, :name)
# => [[1, "David"], [2, "Rafael"]]
sole() Link
Returns the sole item in the enumerable. If there are no items, or more than one item, raises Enumerable::SoleItemExpectedError
.
["x"].sole # => "x"
Set.new.sole # => Enumerable::SoleItemExpectedError: no item found
{ a: 1, b: 2 }.sole # => Enumerable::SoleItemExpectedError: multiple items found
# File activesupport/lib/active_support/core_ext/enumerable.rb, line 211 def sole case count when 1 then return first # rubocop:disable Style/RedundantReturn when 0 then raise ActiveSupport::EnumerableCoreExt::SoleItemExpectedError, "no item found" when 2.. then raise ActiveSupport::EnumerableCoreExt::SoleItemExpectedError, "multiple items found" end end