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Diffstat (limited to 'guides/source/active_support_core_extensions.md')
| -rw-r--r-- | guides/source/active_support_core_extensions.md | 30 |
1 files changed, 21 insertions, 9 deletions
diff --git a/guides/source/active_support_core_extensions.md b/guides/source/active_support_core_extensions.md index 2a643680f7..01bf928407 100644 --- a/guides/source/active_support_core_extensions.md +++ b/guides/source/active_support_core_extensions.md @@ -1936,6 +1936,8 @@ as well as adding or subtracting their results from a Time object. For example: (4.months + 5.years).from_now ``` +NOTE: Defined in `active_support/core_ext/numeric/time.rb` + ### Formatting Enables the formatting of numbers in a variety of ways. @@ -2193,6 +2195,16 @@ removed: NOTE: Defined in `active_support/core_ext/enumerable.rb`. +### `pluck` + +The method `pluck` returns an array based on the given key: + +```ruby +[{ name: "David" }, { name: "Rafael" }, { name: "Aaron" }].pluck(:name) # => ["David", "Rafael", "Aaron"] +``` + +NOTE: Defined in `active_support/core_ext/enumerable.rb`. + Extensions to `Array` --------------------- @@ -2201,14 +2213,14 @@ Extensions to `Array` Active Support augments the API of arrays to ease certain ways of accessing them. For example, `to` returns the subarray of elements up to the one at the passed index: ```ruby -%w(a b c d).to(2) # => %w(a b c) +%w(a b c d).to(2) # => ["a", "b", "c"] [].to(7) # => [] ``` Similarly, `from` returns the tail from the element at the passed index to the end. If the index is greater than the length of the array, it returns an empty array. ```ruby -%w(a b c d).from(2) # => %w(c d) +%w(a b c d).from(2) # => ["c", "d"] %w(a b c d).from(10) # => [] [].from(0) # => [] ``` @@ -2216,7 +2228,7 @@ Similarly, `from` returns the tail from the element at the passed index to the e The methods `second`, `third`, `fourth`, and `fifth` return the corresponding element (`first` is built-in). Thanks to social wisdom and positive constructiveness all around, `forty_two` is also available. ```ruby -%w(a b c d).third # => c +%w(a b c d).third # => "c" %w(a b c d).fifth # => nil ``` @@ -2229,7 +2241,7 @@ NOTE: Defined in `active_support/core_ext/array/access.rb`. This method is an alias of `Array#unshift`. ```ruby -%w(a b c d).prepend('e') # => %w(e a b c d) +%w(a b c d).prepend('e') # => ["e", "a", "b", "c", "d"] [].prepend(10) # => [10] ``` @@ -2240,8 +2252,8 @@ NOTE: Defined in `active_support/core_ext/array/prepend_and_append.rb`. This method is an alias of `Array#<<`. ```ruby -%w(a b c d).append('e') # => %w(a b c d e) -[].append([1,2]) # => [[1,2]] +%w(a b c d).append('e') # => ["a", "b", "c", "d", "e"] +[].append([1,2]) # => [[1, 2]] ``` NOTE: Defined in `active_support/core_ext/array/prepend_and_append.rb`. @@ -2465,7 +2477,7 @@ NOTE: Defined in `active_support/core_ext/array/wrap.rb`. ### Duplicating -The method `Array.deep_dup` duplicates itself and all objects inside +The method `Array#deep_dup` duplicates itself and all objects inside recursively with Active Support method `Object#deep_dup`. It works like `Array#map` with sending `deep_dup` method to each object inside. ```ruby @@ -2687,7 +2699,7 @@ NOTE: Defined in `active_support/core_ext/hash/deep_merge.rb`. ### Deep duplicating -The method `Hash.deep_dup` duplicates itself and all keys and values +The method `Hash#deep_dup` duplicates itself and all keys and values inside recursively with Active Support method `Object#deep_dup`. It works like `Enumerator#each_with_object` with sending `deep_dup` method to each pair inside. ```ruby @@ -2883,7 +2895,7 @@ The method `transform_values` accepts a block and returns a hash that has applie ``` There's also the bang variant `transform_values!` that applies the block operations to values in the very receiver. -NOTE: Defined in `active_support/core_text/hash/transform_values.rb`. +NOTE: Defined in `active_support/core_ext/hash/transform_values.rb`. ### Slicing |