An iterator that can be used as an argument for other iterators that require a RecursiveIterator but do not want children. This iterator will always behave as having no nested items.
Returns an array that can be used to describe the internal state of this object.
Returns a callable that receives a value and will return whether or not it matches certain condition.
Returns a column from $data that can be extracted by iterating over the column names contained in $path.
Returns a callable that can be used to extract a property or column from an array or object based on a dot separated path.
Returns a column from $data that can be extracted by iterating over the column names contained in $path
Returns a new collection as the result of concatenating the list of elements in this collection with the passed list of elements
Create a new collection that is the cartesian product of the current collection
Returns a new collection where the values extracted based on a value path and then indexed by a key path. Optionally this method can produce parent groups based on a group property path.
Iterates once all elements in this collection and executes all stacked operations of them, finally it returns a new collection with the result.
Returns true if $value is present in this collection. Comparisons are made both by value and type.
Sorts a list into groups and returns a count for the number of elements in each group. Similar to groupBy, but instead of returning a list of values, returns a count for the number of values in that group.
Returns the number of unique keys in this iterator. This is the same as the number of elements the collection will contain after calling toArray()
Returns true if all values in this collection pass the truth test provided in the callback.
Returns a new collection containing the column or property value found in each of the elements.
Looks through each value in the collection, and returns another collection with all the values that pass a truth test. Only the values for which the callback returns true will be present in the resulting collection.
Returns the first result matching all of the key-value pairs listed in conditions.
Splits a collection into sets, grouped by the result of running each value through the callback. If $callback is a string instead of a callable, groups by the property named by $callback on each of the values.
Given a list and a callback function that returns a key for each element in the list (or a property name), returns an object with an index of each item.
Returns a new collection containing each of the elements found in $values
as a property inside the corresponding elements in this collection. The property where the values will be inserted is described by the $path
parameter.
Returns the data that can be converted to JSON. This returns the same data as toArray()
which contains only unique keys.
Returns a new collection where any operations chained after it are guaranteed to be run lazily. That is, elements will be yieleded one at a time.
Returns a new collection with each of the elements of this collection after flattening the tree structure. The tree structure is defined by nesting elements under a key with a known name. It is possible to specify such name by using the '$nestingKey' parameter.
Returns another collection after modifying each of the values in this one using the provided callable.
Looks through each value in the list, returning a Collection of all the values that contain all of the key-value pairs listed in $conditions.
Returns a new collection where the values are nested in a tree-like structure based on an id property path and a parent id property path.
Unwraps this iterator and returns the simplest traversable that can be used for getting the data out
Folds the values in this collection to a single value, as the result of applying the callback function to all elements. $zero is the initial state of the reduction, and each successive step of it should be returned by the callback function.
Looks through each value in the collection, and returns another collection with all the values that do not pass a truth test. This is the opposite of filter
.
Returns a string representation of this object that can be used to reconstruct it
Returns a new collection with the elements placed in a random order, this function does not preserve the original keys in the collection.
Returns a new collection that will skip the specified amount of elements at the beginning of the iteration.
Returns true if any of the values in this collection pass the truth test provided in the callback.
Returns a sorted iterator out of the elements in this collection, ranked in ascending order by the results of running each value through a callback. $callback can also be a string representing the column or property name.
Creates a new collection that when iterated will stop yielding results if the provided condition evaluates to true.
Returns the total sum of all the values extracted with $matcher or of this collection.
Returns a new collection with maximum $size elements in the internal order this collection was created. If a second parameter is passed, it will determine from what position to start taking elements.
Creates a new collection where the items are the concatenation of the lists of items generated by the transformer function applied to each item in the original collection.
Returns the closest nested iterator that can be safely traversed without losing any possible transformations. This is used mainly to remove empty IteratorIterator wrappers that can only slowdown the iteration process.
Combines the elements of this collection with each of the elements of the passed iterables, using their positional index as a reference.
Combines the elements of this collection with each of the elements of the passed iterables, using their positional index as a reference.
__construct(iterable $items)
Constructor. You can provide an array or any traversable object
iterable
$items Items.
InvalidArgumentException
__debugInfo()
Returns an array that can be used to describe the internal state of this object.
array
_createMatcherFilter(array $conditions)
Returns a callable that receives a value and will return whether or not it matches certain condition.
array
$conditions A key-value list of conditions to match where the key is the property path to get from the current item and the value is the value to be compared the item with.
\Closure
_extract(mixed $data, array $path)
Returns a column from $data that can be extracted by iterating over the column names contained in $path.
It will return arrays for elements in represented with {*}
array|\ArrayAccess
$data Data.
string[]
$path Path to extract from.
mixed
_propertyExtractor(mixed $callback)
Returns a callable that can be used to extract a property or column from an array or object based on a dot separated path.
string|callable
$callback A dot separated path of column to follow so that the final one can be returned or a callable that will take care of doing that.
callable
_simpleExtract(mixed $data, array $path)
Returns a column from $data that can be extracted by iterating over the column names contained in $path
array|\ArrayAccess
$data Data.
string[]
$path Path to extract from.
mixed
append(mixed $items)
Returns a new collection as the result of concatenating the list of elements in this collection with the passed list of elements
iterable
$items Items list.
self
appendItem(mixed $item, mixed $key)
Append a single item creating a new collection.
mixed
$item The item to append.
mixed
$key optional The key to append the item with. If null a key will be generated.
self
avg(mixed $path)
Returns the average of all the values extracted with $path or of this collection.
$items = [ ['invoice' => ['total' => 100]], ['invoice' => ['total' => 200]] ]; $total = (new Collection($items))->avg('invoice.total'); // Total: 150 $total = (new Collection([1, 2, 3]))->avg(); // Total: 2
string|callable|null
$path optional The property name to sum or a function If no value is passed, an identity function will be used. that will return the value of the property to sum.
float|int|null
buffered()
Returns a new collection where the operations performed by this collection.
No matter how many times the new collection is iterated, those operations will only be performed once.
This can also be used to make any non-rewindable iterator rewindable.
self
cartesianProduct(?callable $operation, ?callable $filter)
Create a new collection that is the cartesian product of the current collection
In order to create a carteisan product a collection must contain a single dimension of data.
$collection = new Collection([['A', 'B', 'C'], [1, 2, 3]]); $result = $collection->cartesianProduct()->toArray(); $expected = [ ['A', 1], ['A', 2], ['A', 3], ['B', 1], ['B', 2], ['B', 3], ['C', 1], ['C', 2], ['C', 3], ];
callable|null
$operation optional A callable that allows you to customize the product result.
callable|null
$filter optional A filtering callback that must return true for a result to be part of the final results.
\Cake\Collection\CollectionInterface
LogicException
chunk(int $chunkSize)
Breaks the collection into smaller arrays of the given size.
$items [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]; $chunked = (new Collection($items))->chunk(3)->toList(); // Returns [[1, 2, 3], [4, 5, 6], [7, 8, 9], [10, 11]]
int
$chunkSize The maximum size for each chunk
self
chunkWithKeys(int $chunkSize, bool $preserveKeys)
Breaks the collection into smaller arrays of the given size.
$items ['a' => 1, 'b' => 2, 'c' => 3, 'd' => 4, 'e' => 5, 'f' => 6]; $chunked = (new Collection($items))->chunkWithKeys(3)->toList(); // Returns [['a' => 1, 'b' => 2, 'c' => 3], ['d' => 4, 'e' => 5, 'f' => 6]]
int
$chunkSize The maximum size for each chunk
bool
$preserveKeys optional If the keys of the array should be preserved
self
combine(mixed $keyPath, mixed $valuePath, mixed $groupPath)
Returns a new collection where the values extracted based on a value path and then indexed by a key path. Optionally this method can produce parent groups based on a group property path.
$items = [ ['id' => 1, 'name' => 'foo', 'parent' => 'a'], ['id' => 2, 'name' => 'bar', 'parent' => 'b'], ['id' => 3, 'name' => 'baz', 'parent' => 'a'], ]; $combined = (new Collection($items))->combine('id', 'name'); // Result will look like this when converted to array [ 1 => 'foo', 2 => 'bar', 3 => 'baz', ]; $combined = (new Collection($items))->combine('id', 'name', 'parent'); // Result will look like this when converted to array [ 'a' => [1 => 'foo', 3 => 'baz'], 'b' => [2 => 'bar'] ];
callable|string
$keyPath the column name path to use for indexing or a function returning the indexing key out of the provided element
callable|string
$valuePath the column name path to use as the array value or a function returning the value out of the provided element
callable|string|null
$groupPath optional the column name path to use as the parent grouping key or a function returning the key out of the provided element
self
compile(bool $preserveKeys)
Iterates once all elements in this collection and executes all stacked operations of them, finally it returns a new collection with the result.
This is useful for converting non-rewindable internal iterators into a collection that can be rewound and used multiple times.
A common use case is to re-use the same variable for calculating different data. In those cases it may be helpful and more performant to first compile a collection and then apply more operations to it.
$collection->map($mapper)->sortBy('age')->extract('name'); $compiled = $collection->compile(); $isJohnHere = $compiled->some($johnMatcher); $allButJohn = $compiled->filter($johnMatcher);
In the above example, had the collection not been compiled before, the iterations for map
, sortBy
and extract
would've been executed twice: once for getting $isJohnHere
and once for $allButJohn
You can think of this method as a way to create save points for complex calculations in a collection.
bool
$preserveKeys optional whether to use the keys returned by this collection as the array keys. Keep in mind that it is valid for iterators to return the same key for different elements, setting this value to false can help getting all items if keys are not important in the result.
self
contains(mixed $value)
Returns true if $value is present in this collection. Comparisons are made both by value and type.
mixed
$value The value to check for
bool
true if $value is present in this collection
count()
Returns the amount of elements in the collection.
Calling this method at the same time that you are iterating this collections, for example in a foreach, will result in undefined behavior. Avoid doing this.
On certain type of collections, calling this method may render unusable afterwards. That is, you may not be able to get elements out of it, or to iterate on it anymore.
Specifically any collection wrapping a Generator (a function with a yield statement) or a unbuffered database cursor will not accept any other function calls after calling count()
on it.
Create a new collection with buffered()
method to overcome this problem.
Any collection constructed by appending collections together, or by having internal iterators returning duplicate keys, will report a larger amount of elements using this functions than the final amount of elements when converting the collections to a keyed array. This is because duplicate keys will be collapsed into a single one in the final array, whereas this count method is only concerned by the amount of elements after converting it to a plain list.
If you need the count of elements after taking the keys in consideration (the count of unique keys), you can call countKeys()
int
countBy(mixed $callback)
Sorts a list into groups and returns a count for the number of elements in each group. Similar to groupBy, but instead of returning a list of values, returns a count for the number of values in that group.
When $callback is a string it should be a property name to extract or a dot separated path of properties that should be followed to get the last one in the path.
$items = [ ['id' => 1, 'name' => 'foo', 'parent_id' => 10], ['id' => 2, 'name' => 'bar', 'parent_id' => 11], ['id' => 3, 'name' => 'baz', 'parent_id' => 10], ]; $group = (new Collection($items))->countBy('parent_id'); // Or $group = (new Collection($items))->countBy(function ($e) { return $e['parent_id']; }); // Result will look like this when converted to array [ 10 => 2, 11 => 1 ];
callable|string
$callback the callback or column name to use for indexing or a function returning the indexing key out of the provided element
self
countKeys()
Returns the number of unique keys in this iterator. This is the same as the number of elements the collection will contain after calling toArray()
This method comes with a number of caveats. Please refer to CollectionInterface::count()
for details.
int
each(callable $callback)
Applies a callback to the elements in this collection.
$collection = (new Collection($items))->each(function ($value, $key) { echo "Element $key: $value"; });
callable
$callback Callback to run for each element in collection.
$this
every(callable $callback)
Returns true if all values in this collection pass the truth test provided in the callback.
Each time the callback is executed it will receive the value of the element in the current iteration and the key of the element as arguments, in that order.
$overTwentyOne = (new Collection([24, 45, 60, 15]))->every(function ($value, $key) { return $value > 21; });
Empty collections always return true because it is a vacuous truth.
callable
$callback a callback function
bool
true if for all elements in this collection the provided callback returns true, false otherwise.
extract(mixed $path)
Returns a new collection containing the column or property value found in each of the elements.
The matcher can be a string with a property name to extract or a dot separated path of properties that should be followed to get the last one in the path.
If a column or property could not be found for a particular element in the collection, that position is filled with null.
Extract the user name for all comments in the array:
$items = [ ['comment' => ['body' => 'cool', 'user' => ['name' => 'Mark']], ['comment' => ['body' => 'very cool', 'user' => ['name' => 'Renan']] ]; $extracted = (new Collection($items))->extract('comment.user.name'); // Result will look like this when converted to array ['Mark', 'Renan']
It is also possible to extract a flattened collection out of nested properties
$items = [ ['comment' => ['votes' => [['value' => 1], ['value' => 2], ['value' => 3]]], ['comment' => ['votes' => [['value' => 4]] ]; $extracted = (new Collection($items))->extract('comment.votes.{*}.value'); // Result will contain [1, 2, 3, 4]
string|callable
$path A dot separated path of column to follow so that the final one can be returned or a callable that will take care of doing that.
self
filter(?callable $callback)
Looks through each value in the collection, and returns another collection with all the values that pass a truth test. Only the values for which the callback returns true will be present in the resulting collection.
Each time the callback is executed it will receive the value of the element in the current iteration, the key of the element and this collection as arguments, in that order.
Filtering odd numbers in an array, at the end only the value 2 will be present in the resulting collection:
$collection = (new Collection([1, 2, 3]))->filter(function ($value, $key) { return $value % 2 === 0; });
callable|null
$callback optional the method that will receive each of the elements and returns true whether or not they should be in the resulting collection. If left null, a callback that filters out falsey values will be used.
self
first()
Returns the first result in this collection
mixed
The first value in the collection will be returned.
firstMatch(array $conditions)
Returns the first result matching all of the key-value pairs listed in conditions.
array
$conditions a key-value list of conditions where the key is a property path as accepted by Collection::extract
, and the value the condition against with each element will be matched
mixed
getChildren()
Returns a self instance without any elements.
\RecursiveIterator
groupBy(mixed $callback)
Splits a collection into sets, grouped by the result of running each value through the callback. If $callback is a string instead of a callable, groups by the property named by $callback on each of the values.
When $callback is a string it should be a property name to extract or a dot separated path of properties that should be followed to get the last one in the path.
$items = [ ['id' => 1, 'name' => 'foo', 'parent_id' => 10], ['id' => 2, 'name' => 'bar', 'parent_id' => 11], ['id' => 3, 'name' => 'baz', 'parent_id' => 10], ]; $group = (new Collection($items))->groupBy('parent_id'); // Or $group = (new Collection($items))->groupBy(function ($e) { return $e['parent_id']; }); // Result will look like this when converted to array [ 10 => [ ['id' => 1, 'name' => 'foo', 'parent_id' => 10], ['id' => 3, 'name' => 'baz', 'parent_id' => 10], ], 11 => [ ['id' => 2, 'name' => 'bar', 'parent_id' => 11], ] ];
callable|string
$callback the callback or column name to use for grouping or a function returning the grouping key out of the provided element
self
hasChildren()
Returns false as there are no children iterators in this collection
bool
indexBy(mixed $callback)
Given a list and a callback function that returns a key for each element in the list (or a property name), returns an object with an index of each item.
Just like groupBy, but for when you know your keys are unique.
When $callback is a string it should be a property name to extract or a dot separated path of properties that should be followed to get the last one in the path.
$items = [ ['id' => 1, 'name' => 'foo'], ['id' => 2, 'name' => 'bar'], ['id' => 3, 'name' => 'baz'], ]; $indexed = (new Collection($items))->indexBy('id'); // Or $indexed = (new Collection($items))->indexBy(function ($e) { return $e['id']; }); // Result will look like this when converted to array [ 1 => ['id' => 1, 'name' => 'foo'], 3 => ['id' => 3, 'name' => 'baz'], 2 => ['id' => 2, 'name' => 'bar'], ];
callable|string
$callback the callback or column name to use for indexing or a function returning the indexing key out of the provided element
self
insert(string $path, mixed $values)
Returns a new collection containing each of the elements found in $values
as a property inside the corresponding elements in this collection. The property where the values will be inserted is described by the $path
parameter.
The $path can be a string with a property name or a dot separated path of properties that should be followed to get the last one in the path.
If a column or property could not be found for a particular element in the collection as part of the path, the element will be kept unchanged.
Insert ages into a collection containing users:
$items = [ ['comment' => ['body' => 'cool', 'user' => ['name' => 'Mark']], ['comment' => ['body' => 'awesome', 'user' => ['name' => 'Renan']] ]; $ages = [25, 28]; $inserted = (new Collection($items))->insert('comment.user.age', $ages); // Result will look like this when converted to array [ ['comment' => ['body' => 'cool', 'user' => ['name' => 'Mark', 'age' => 25]], ['comment' => ['body' => 'awesome', 'user' => ['name' => 'Renan', 'age' => 28]] ];
string
$path a dot separated string symbolizing the path to follow inside the hierarchy of each value so that the value can be inserted
mixed
$values The values to be inserted at the specified path, values are matched with the elements in this collection by its positional index.
self
isEmpty()
Returns whether or not there are elements in this collection
$items [1, 2, 3]; (new Collection($items))->isEmpty(); // false
(new Collection([]))->isEmpty(); // true
bool
jsonSerialize()
Returns the data that can be converted to JSON. This returns the same data as toArray()
which contains only unique keys.
Part of JsonSerializable interface.
array
The data to convert to JSON
last()
Returns the last result in this collection
mixed
The last value in the collection will be returned.
lazy()
Returns a new collection where any operations chained after it are guaranteed to be run lazily. That is, elements will be yieleded one at a time.
A lazy collection can only be iterated once. A second attempt results in an error.
self
listNested(mixed $order, mixed $nestingKey)
Returns a new collection with each of the elements of this collection after flattening the tree structure. The tree structure is defined by nesting elements under a key with a known name. It is possible to specify such name by using the '$nestingKey' parameter.
By default all elements in the tree following a Depth First Search will be returned, that is, elements from the top parent to the leaves for each branch.
It is possible to return all elements from bottom to top using a Breadth First Search approach by passing the '$dir' parameter with 'asc'. That is, it will return all elements for the same tree depth first and from bottom to top.
Finally, you can specify to only get a collection with the leaf nodes in the tree structure. You do so by passing 'leaves' in the first argument.
The possible values for the first argument are aliases for the following constants and it is valid to pass those instead of the alias:
$collection = new Collection([ ['id' => 1, 'children' => [['id' => 2, 'children' => [['id' => 3]]]]], ['id' => 4, 'children' => [['id' => 5]]] ]); $flattenedIds = $collection->listNested()->extract('id'); // Yields [1, 2, 3, 4, 5]
string|int
$order optional The order in which to return the elements
string|callable
$nestingKey optional The key name under which children are nested or a callable function that will return the children list
self
map(callable $callback)
Returns another collection after modifying each of the values in this one using the provided callable.
Each time the callback is executed it will receive the value of the element in the current iteration, the key of the element and this collection as arguments, in that order.
Getting a collection of booleans where true indicates if a person is female:
$collection = (new Collection($people))->map(function ($person, $key) { return $person->gender === 'female'; });
callable
$callback the method that will receive each of the elements and returns the new value for the key that is being iterated
self
match(array $conditions)
Looks through each value in the list, returning a Collection of all the values that contain all of the key-value pairs listed in $conditions.
$items = [ ['comment' => ['body' => 'cool', 'user' => ['name' => 'Mark']], ['comment' => ['body' => 'very cool', 'user' => ['name' => 'Renan']] ]; $extracted = (new Collection($items))->match(['user.name' => 'Renan']); // Result will look like this when converted to array [ ['comment' => ['body' => 'very cool', 'user' => ['name' => 'Renan']] ]
array
$conditions a key-value list of conditions where the key is a property path as accepted by `Collection::extract, and the value the condition against with each element will be matched
self
max(mixed $callback, int $sort)
Returns the top element in this collection after being sorted by a property.
Check the sortBy method for information on the callback and $sort parameters
// For a collection of employees $max = $collection->max('age'); $max = $collection->max('user.salary'); $max = $collection->max(function ($e) { return $e->get('user')->get('salary'); }); // Display employee name echo $max->name;
callable|string
$callback the callback or column name to use for sorting
int
$sort optional The sort type, one of SORT_STRING SORT_NUMERIC or SORT_NATURAL
mixed
The value of the top element in the collection
median(mixed $path)
Returns the median of all the values extracted with $path or of this collection.
$items = [ ['invoice' => ['total' => 400]], ['invoice' => ['total' => 500]] ['invoice' => ['total' => 100]] ['invoice' => ['total' => 333]] ['invoice' => ['total' => 200]] ]; $total = (new Collection($items))->median('invoice.total'); // Total: 333 $total = (new Collection([1, 2, 3, 4]))->median(); // Total: 2.5
string|callable|null
$path optional The property name to sum or a function If no value is passed, an identity function will be used. that will return the value of the property to sum.
float|int|null
min(mixed $callback, int $sort)
Returns the bottom element in this collection after being sorted by a property.
Check the sortBy method for information on the callback and $sort parameters
// For a collection of employees $min = $collection->min('age'); $min = $collection->min('user.salary'); $min = $collection->min(function ($e) { return $e->get('user')->get('salary'); }); // Display employee name echo $min->name;
callable|string
$callback the callback or column name to use for sorting
int
$sort optional The sort type, one of SORT_STRING SORT_NUMERIC or SORT_NATURAL
mixed
The value of the bottom element in the collection
nest(mixed $idPath, mixed $parentPath, string $nestingKey)
Returns a new collection where the values are nested in a tree-like structure based on an id property path and a parent id property path.
callable|string
$idPath the column name path to use for determining whether an element is parent of another
callable|string
$parentPath the column name path to use for determining whether an element is child of another
string
$nestingKey optional The key name under which children are nested
self
newCollection(mixed ...$args)
Returns a new collection.
Allows classes which use this trait to determine their own type of returned collection interface
mixed
...$args Constructor arguments.
\Cake\Collection\CollectionInterface
optimizeUnwrap()
Unwraps this iterator and returns the simplest traversable that can be used for getting the data out
iterable
prepend(mixed $items)
Prepend a set of items to a collection creating a new collection
mixed
$items The items to prepend.
self
prependItem(mixed $item, mixed $key)
Prepend a single item creating a new collection.
mixed
$item The item to prepend.
mixed
$key optional The key to prepend the item with. If null a key will be generated.
self
reduce(callable $callback, mixed $initial)
Folds the values in this collection to a single value, as the result of applying the callback function to all elements. $zero is the initial state of the reduction, and each successive step of it should be returned by the callback function.
If $zero is omitted the first value of the collection will be used in its place and reduction will start from the second item.
callable
$callback The callback function to be called
mixed
$initial optional The state of reduction
mixed
reject(callable $callback)
Looks through each value in the collection, and returns another collection with all the values that do not pass a truth test. This is the opposite of filter
.
Each time the callback is executed it will receive the value of the element in the current iteration, the key of the element and this collection as arguments, in that order.
Filtering even numbers in an array, at the end only values 1 and 3 will be present in the resulting collection:
$collection = (new Collection([1, 2, 3]))->reject(function ($value, $key) { return $value % 2 === 0; });
callable
$callback the method that will receive each of the elements and returns true whether or not they should be out of the resulting collection.
self
sample(int $length)
Returns a new collection with maximum $size random elements from this collection
int
$length optional the maximum number of elements to randomly take from this collection
self
serialize()
Returns a string representation of this object that can be used to reconstruct it
string
shuffle()
Returns a new collection with the elements placed in a random order, this function does not preserve the original keys in the collection.
self
skip(int $length)
Returns a new collection that will skip the specified amount of elements at the beginning of the iteration.
int
$length The number of elements to skip.
self
some(callable $callback)
Returns true if any of the values in this collection pass the truth test provided in the callback.
Each time the callback is executed it will receive the value of the element in the current iteration and the key of the element as arguments, in that order.
$hasYoungPeople = (new Collection([24, 45, 15]))->every(function ($value, $key) { return $value < 21; });
callable
$callback a callback function
bool
true if the provided callback returns true for any element in this collection, false otherwise
sortBy(mixed $callback, int $order, int $sort)
Returns a sorted iterator out of the elements in this collection, ranked in ascending order by the results of running each value through a callback. $callback can also be a string representing the column or property name.
The callback will receive as its first argument each of the elements in $items, the value returned by the callback will be used as the value for sorting such element. Please note that the callback function could be called more than once per element.
$items = $collection->sortBy(function ($user) { return $user->age; }); // alternatively $items = $collection->sortBy('age'); // or use a property path $items = $collection->sortBy('department.name'); // output all user name order by their age in descending order foreach ($items as $user) { echo $user->name; }
callable|string
$callback the callback or column name to use for sorting
int
$order optional The sort order, either SORT_DESC or SORT_ASC
int
$sort optional The sort type, one of SORT_STRING SORT_NUMERIC or SORT_NATURAL
self
stopWhen(mixed $condition)
Creates a new collection that when iterated will stop yielding results if the provided condition evaluates to true.
This is handy for dealing with infinite iterators or any generator that could start returning invalid elements at a certain point. For example, when reading lines from a file stream you may want to stop the iteration after a certain value is reached.
Get an array of lines in a CSV file until the timestamp column is less than a date
$lines = (new Collection($fileLines))->stopWhen(function ($value, $key) { return (new DateTime($value))->format('Y') < 2012; }) ->toArray();
Get elements until the first unapproved message is found:
$comments = (new Collection($comments))->stopWhen(['is_approved' => false]);
callable|array
$condition the method that will receive each of the elements and returns true when the iteration should be stopped. If an array, it will be interpreted as a key-value list of conditions where the key is a property path as accepted by Collection::extract
, and the value the condition against with each element will be matched.
self
sumOf(mixed $path)
Returns the total sum of all the values extracted with $matcher or of this collection.
$items = [ ['invoice' => ['total' => 100]], ['invoice' => ['total' => 200]] ]; $total = (new Collection($items))->sumOf('invoice.total'); // Total: 300 $total = (new Collection([1, 2, 3]))->sumOf(); // Total: 6
string|callable|null
$path optional The property name to sum or a function If no value is passed, an identity function will be used. that will return the value of the property to sum.
float|int
take(int $length, int $offset)
Returns a new collection with maximum $size elements in the internal order this collection was created. If a second parameter is passed, it will determine from what position to start taking elements.
int
$length optional the maximum number of elements to take from this collection
int
$offset optional A positional offset from where to take the elements
self
takeLast(int $length)
Returns the last N elements of a collection
$items = [1, 2, 3, 4, 5]; $last = (new Collection($items))->takeLast(3); // Result will look like this when converted to array [3, 4, 5];
int
$length The number of elements at the end of the collection
self
through(callable $callback)
Passes this collection through a callable as its first argument.
This is useful for decorating the full collection with another object.
$items = [1, 2, 3]; $decorated = (new Collection($items))->through(function ($collection) { return new MyCustomCollection($collection); });
callable
$callback A callable function that will receive this collection as first argument.
self
toArray(bool $preserveKeys)
Returns an array representation of the results
bool
$preserveKeys optional whether to use the keys returned by this collection as the array keys. Keep in mind that it is valid for iterators to return the same key for different elements, setting this value to false can help getting all items if keys are not important in the result.
array
toList()
Returns an numerically-indexed array representation of the results.
This is equivalent to calling toArray(false)
array
transpose()
Transpose rows and columns into columns and rows
$items = [ ['Products', '2012', '2013', '2014'], ['Product A', '200', '100', '50'], ['Product B', '300', '200', '100'], ['Product C', '400', '300', '200'], ] $transpose = (new Collection($items))->transpose()->toList(); // Returns // [ // ['Products', 'Product A', 'Product B', 'Product C'], // ['2012', '200', '300', '400'], // ['2013', '100', '200', '300'], // ['2014', '50', '100', '200'], // ]
\Cake\Collection\CollectionInterface
LogicException
unfold(?callable $callback)
Creates a new collection where the items are the concatenation of the lists of items generated by the transformer function applied to each item in the original collection.
The transformer function will receive the value and the key for each of the items in the collection, in that order, and it must return an array or a Traversable object that can be concatenated to the final result.
If no transformer function is passed, an "identity" function will be used. This is useful when each of the elements in the source collection are lists of items to be appended one after another.
$items [[1, 2, 3], [4, 5]]; $unfold = (new Collection($items))->unfold(); // Returns [1, 2, 3, 4, 5]
Using a transformer
$items [1, 2, 3]; $allItems = (new Collection($items))->unfold(function ($page) { return $service->fetchPage($page)->toArray(); });
callable|null
$callback optional A callable function that will receive each of the items in the collection and should return an array or Traversable object
self
unserialize(mixed $collection)
Unserializes the passed string and rebuilds the Collection instance
string
$collection The serialized collection
unwrap()
Returns the closest nested iterator that can be safely traversed without losing any possible transformations. This is used mainly to remove empty IteratorIterator wrappers that can only slowdown the iteration process.
\Traversable
zip(iterable $items)
Combines the elements of this collection with each of the elements of the passed iterables, using their positional index as a reference.
$collection = new Collection([1, 2]); $collection->zip([3, 4], [5, 6])->toList(); // returns [[1, 3, 5], [2, 4, 6]]
iterable
$items The collections to zip.
self
zipWith(iterable $items, mixed $callback)
Combines the elements of this collection with each of the elements of the passed iterables, using their positional index as a reference.
The resulting element will be the return value of the $callable function.
$collection = new Collection([1, 2]); $zipped = $collection->zipWith([3, 4], [5, 6], function (...$args) { return array_sum($args); }); $zipped->toList(); // returns [9, 12]; [(1 + 3 + 5), (2 + 4 + 6)]
iterable
$items The collections to zip.
callable
$callback The function to use for zipping the elements together.
self
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https://api.cakephp.org/4.1/class-Cake.Collection.Iterator.NoChildrenIterator.html