instance method `index_by`

Ruby on Rails 3.1.12

Since v2.2.3

Available in: v2.2.3 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 v6.0.6 v6.1.7.10 v7.0.10 v7.1.6 v7.2.3 v8.0.4 v8.1.2

Compare with:

index_by()

Convert an enumerable to a hash. Examples:

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 ...>, ...}

Source

# File activesupport/lib/active_support/core_ext/enumerable.rb, line 92
  def index_by
    Hash[map { |elem| [yield(elem), elem] }]
  end

Defined in activesupport/lib/active_support/core_ext/enumerable.rb line 92 · View on GitHub · Improve this page · Find usages on GitHub

Defined in Enumerable

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