laravel的Collection工具類對php的數組處理函數進行了封裝，開發者可以鏈式調用Collection中的方法，從而優雅地處理數組類的數據。
<?php
namespace Illuminate\Support;
use ArrayAccess;
use ArrayIterator;
use Illuminate\Support\Traits\EnumeratesValues;
use Illuminate\Support\Traits\Macroable;
use stdClass;
/* Collection集合類 實現了兩個接口，一個是php內置的數組訪問接口，一個是枚舉接口*/
class Collection implements ArrayAccess, Enumerable
{
// 引入了兩個特性，
use EnumeratesValues, Macroable;
/**
* The items contained in the collection.
*保存要處理的數組數據，這個類中所有的方法基本都是在處理這個屬性
* @var array
*/
protected $items = [];
/**
* Create a new collection.
*構造方法，參數是一個數組，保存到本類的唯一屬性$items中，之後調用方法處理
*
* @param mixed $items
* @return void
*/
public function __construct($items = [])
{
$this->items = $this->getArrayableItems($items);
}
/**
* Create a new collection by invoking the callback a given amount of times.
*靜態方法，調用固定次數的閉包函數處理數據後，創建一個新的集合類。
* @param int $number
* @param callable|null $callback
* @return static
*/
public static function times($number, callable $callback = null)
{
// $number參數小於1，直接實例化
if ($number < 1) {
return new static;
}
// 如果閉包函數爲空，將連續的數字數組 [1,2,....$number] 作爲參數實例化集合類
if (is_null($callback)) {
return new static(range(1, $number));
}
// 用連續的數字數組實例化集合類後，調用map方法。 相當於調用了$number次的$collback閉包
return (new static(range(1, $number)))->map($callback);
}
/**
* Get all of the items in the collection.
*
* @return array
*/
public function all()
{
// 返回本對象包裝的數組
return $this->items;
}
/**
* Get a lazy collection for the items in this collection.
*
* @return \Illuminate\Support\LazyCollection
*/
public function lazy()
{
// 用LazyCollection類 包裝 本對象的數組數據
return new LazyCollection($this->items);
}
/**
* Get the average value of a given key.
*獲取指定鍵名的平均數
*
* @param callable|string|null $callback
* @return mixed
*/
public function avg($callback = null)
{
// 調用valueRetriever方法處理$callback參數，這個方法定義在特性類EnumeratesValues裏，且返回的數據是一個閉包。若 $callback 參數是字符串，返回的閉包可以用來檢索鍵名爲$callback的數據。
$callback = $this->valueRetriever($callback);
$items = $this->map(function ($value) use ($callback) {
// 調用map方法處理每一個數據，返回閉包處理後的數據
return $callback($value);
})->filter(function ($value) {
// 篩掉值爲null的數據
return ! is_null($value);
});
if ($count = $items->count()) {
return $items->sum() / $count;
}
}
/**
* Get the median of a given key.
*返回給定 鍵名 數據的的中值
* @param string|array|null $key
* @return mixed
*/
public function median($key = null)
{
$values = (isset($key) ? $this->pluck($key) : $this)
->filter(function ($item) {
return ! is_null($item);
})->sort()->values();
$count = $values->count();
if ($count === 0) {
return;
}
$middle = (int) ($count / 2);
if ($count % 2) {
return $values->get($middle);
}
return (new static([
$values->get($middle - 1), $values->get($middle),
]))->average();
}
/**
* Get the mode of a given key.
*統計元素出現次數，返回出現次數做多的元素
* @param string|array|null $key
* @return array|null
*/
public function mode($key = null)
{
if ($this->count() === 0) {
return;
}
$collection = isset($key) ? $this->pluck($key) : $this;
$counts = new self;
// 統計每個數組元素出現次數
$collection->each(function ($value) use ($counts) {
$counts[$value] = isset($counts[$value]) ? $counts[$value] + 1 : 1;
});
// 排序
$sorted = $counts->sort();
// 獲取出現次數最多的值
$highestValue = $sorted->last();
return $sorted->filter(function ($value) use ($highestValue) {
return $value == $highestValue;
})->sort()->keys()->all();
}
/**
* Collapse the collection of items into a single array.
*將多維數組轉換成一維數組
* @return static
*/
public function collapse()
{
return new static(Arr::collapse($this->items));
}
/**
* Determine if an item exists in the collection.
*判斷 符合特定條件 的元素 是否在 集合裏
*例如，contains('name', '=', 'ldy')，判斷集合中的元素是否 包含 *鍵名爲name，鍵值爲ldy的 元素，返回bool值。
*
* @param mixed $key
* @param mixed $operator
* @param mixed $value
* @return bool
*/
public function contains($key, $operator = null, $value = null)
{
if (func_num_args() === 1) {
// $key是一個可以調用的結構
if ($this->useAsCallable($key)) {
$placeholder = new stdClass;
// 調用 first 方法檢索數據，若最終返回的數據是 first 方法的默認值 $placeholder ，則說明不存在
return $this->first($key, $placeholder) !== $placeholder;
}
return in_array($key, $this->items);
}
// 參數不只一個，調用operatorForWhere函數解析參數，將參數包裝成一個用來比較的閉包，
return $this->contains($this->operatorForWhere(...func_get_args()));
}
/**
* Cross join with the given lists, returning all possible permutations.
*
* @param mixed ...$lists
* @return static
*/
public function crossJoin(...$lists)
{
return new static(Arr::crossJoin(
$this->items, ...array_map([$this, 'getArrayableItems'], $lists)
));
}
/**
* Get the items in the collection that are not present in the given items.
*
* @param mixed $items
* @return static
*/
public function diff($items)
{
return new static(array_diff($this->items, $this->getArrayableItems($items)));
}
/**
* Get the items in the collection that are not present in the given items, using the callback.
*
* @param mixed $items
* @param callable $callback
* @return static
*/
public function diffUsing($items, callable $callback)
{
return new static(array_udiff($this->items, $this->getArrayableItems($items), $callback));
}
/**
* Get the items in the collection whose keys and values are not present in the given items.
*
* @param mixed $items
* @return static
*/
public function diffAssoc($items)
{
return new static(array_diff_assoc($this->items, $this->getArrayableItems($items)));
}
/**
* Get the items in the collection whose keys and values are not present in the given items, using the callback.
*
* @param mixed $items
* @param callable $callback
* @return static
*/
public function diffAssocUsing($items, callable $callback)
{
return new static(array_diff_uassoc($this->items, $this->getArrayableItems($items), $callback));
}
/**
* Get the items in the collection whose keys are not present in the given items.
*
* @param mixed $items
* @return static
*/
public function diffKeys($items)
{
return new static(array_diff_key($this->items, $this->getArrayableItems($items)));
}
/**
* Get the items in the collection whose keys are not present in the given items, using the callback.
*
* @param mixed $items
* @param callable $callback
* @return static
*/
public function diffKeysUsing($items, callable $callback)
{
return new static(array_diff_ukey($this->items, $this->getArrayableItems($items), $callback));
}
/**
* Retrieve duplicate items from the collection.
*
* @param callable|null $callback
* @param bool $strict
* @return static
*/
public function duplicates($callback = null, $strict = false)
{
$items = $this->map($this->valueRetriever($callback));
$uniqueItems = $items->unique(null, $strict);
$compare = $this->duplicateComparator($strict);
$duplicates = new static;
foreach ($items as $key => $value) {
if ($uniqueItems->isNotEmpty() && $compare($value, $uniqueItems->first())) {
$uniqueItems->shift();
} else {
$duplicates[$key] = $value;
}
}
return $duplicates;
}
/**
* Retrieve duplicate items from the collection using strict comparison.
*
* @param callable|null $callback
* @return static
*/
public function duplicatesStrict($callback = null)
{
return $this->duplicates($callback, true);
}
/**
* Get the comparison function to detect duplicates.
*
* @param bool $strict
* @return \Closure
*/
protected function duplicateComparator($strict)
{
if ($strict) {
return function ($a, $b) {
return $a === $b;
};
}
return function ($a, $b) {
return $a == $b;
};
}
/**
* Get all items except for those with the specified keys.
*
* @param \Illuminate\Support\Collection|mixed $keys
* @return static
*/
public function except($keys)
{
if ($keys instanceof Enumerable) {
$keys = $keys->all();
} elseif (! is_array($keys)) {
$keys = func_get_args();
}
return new static(Arr::except($this->items, $keys));
}
/**
* Run a filter over each of the items.
*
* @param callable|null $callback
* @return static
*/
public function filter(callable $callback = null)
{
if ($callback) {
return new static(Arr::where($this->items, $callback));
}
return new static(array_filter($this->items));
}
/**
* Get the first item from the collection passing the given truth test.
*返回第一個通過真值測試的數據
*
* @param callable|null $callback
* @param mixed $default
* @return mixed
*/
public function first(callable $callback = null, $default = null)
{
return Arr::first($this->items, $callback, $default);
}
/**
* Get a flattened array of the items in the collection.
*將多維數組轉化成一位數組
* @param int $depth
* @return static
*/
public function flatten($depth = INF)
{
return new static(Arr::flatten($this->items, $depth));
}
/**
* Flip the items in the collection.
*交換數組中的鍵和值
* @return static
*/
public function flip()
{
//
return new static(array_flip($this->items));
}
/**
* Remove an item from the collection by key.
*從數組中刪除鍵名爲$key的數據
* @param string|array $keys
* @return $this
*/
public function forget($keys)
{
foreach ((array) $keys as $key) {
$this->offsetUnset($key);
}
return $this;
}
/**
* Get an item from the collection by key.
*根據$key從數組中取出數據
* @param mixed $key
* @param mixed $default
* @return mixed
*/
public function get($key, $default = null)
{
if ($this->offsetExists($key)) {
return $this->items[$key];
}
return value($default);
}
/**
* Group an associative array by a field or using a callback.
*
* @param array|callable|string $groupBy
* @param bool $preserveKeys
* @return static
*/
public function groupBy($groupBy, $preserveKeys = false)
{
if (is_array($groupBy)) {
$nextGroups = $groupBy;
$groupBy = array_shift($nextGroups);
}
$groupBy = $this->valueRetriever($groupBy);
$results = [];
foreach ($this->items as $key => $value) {
$groupKeys = $groupBy($value, $key);
if (! is_array($groupKeys)) {
$groupKeys = [$groupKeys];
}
foreach ($groupKeys as $groupKey) {
$groupKey = is_bool($groupKey) ? (int) $groupKey : $groupKey;
if (! array_key_exists($groupKey, $results)) {
$results[$groupKey] = new static;
}
$results[$groupKey]->offsetSet($preserveKeys ? $key : null, $value);
}
}
$result = new static($results);
if (! empty($nextGroups)) {
return $result->map->groupBy($nextGroups, $preserveKeys);
}
return $result;
}
/**
* Key an associative array by a field or using a callback.
*
* @param callable|string $keyBy
* @return static
*/
public function keyBy($keyBy)
{
$keyBy = $this->valueRetriever($keyBy);
$results = [];
foreach ($this->items as $key => $item) {
$resolvedKey = $keyBy($item, $key);
if (is_object($resolvedKey)) {
$resolvedKey = (string) $resolvedKey;
}
$results[$resolvedKey] = $item;
}
return new static($results);
}
/**
* Determine if an item exists in the collection by key.
*
* @param mixed $key
* @return bool
*/
public function has($key)
{
$keys = is_array($key) ? $key : func_get_args();
foreach ($keys as $value) {
if (! $this->offsetExists($value)) {
return false;
}
}
return true;
}
/**
* Concatenate values of a given key as a string.
*
* @param string $value
* @param string|null $glue
* @return string
*/
public function implode($value, $glue = null)
{
$first = $this->first();
if (is_array($first) || is_object($first)) {
return implode($glue, $this->pluck($value)->all());
}
return implode($value, $this->items);
}
/**
* Intersect the collection with the given items.
*
* @param mixed $items
* @return static
*/
public function intersect($items)
{
return new static(array_intersect($this->items, $this->getArrayableItems($items)));
}
/**
* Intersect the collection with the given items by key.
*
* @param mixed $items
* @return static
*/
public function intersectByKeys($items)
{
return new static(array_intersect_key(
$this->items, $this->getArrayableItems($items)
));
}
/**
* Determine if the collection is empty or not.
*判斷是否爲空
* @return bool
*/
public function isEmpty()
{
return empty($this->items);
}
/**
* Join all items from the collection using a string. The final items can use a separate glue string.
*
* @param string $glue
* @param string $finalGlue
* @return string
*/
public function join($glue, $finalGlue = '')
{
if ($finalGlue === '') {
return $this->implode($glue);
}
$count = $this->count();
if ($count === 0) {
return '';
}
if ($count === 1) {
return $this->last();
}
$collection = new static($this->items);
$finalItem = $collection->pop();
return $collection->implode($glue).$finalGlue.$finalItem;
}
/**
* Get the keys of the collection items.
*返回包裝數組的鍵名數組
* @return static
*/
public function keys()
{
return new static(array_keys($this->items));
}
/**
* Get the last item from the collection.
*返回通過真值測試的最後一個元素
* @param callable|null $callback
* @param mixed $default
* @return mixed
*/
public function last(callable $callback = null, $default = null)
{
return Arr::last($this->items, $callback, $default);
}
/**
* Get the values of a given key.
*
* @param string|array $value
* @param string|null $key
* @return static
*/
public function pluck($value, $key = null)
{
// 返回一個新的集合對象，新對象的數組值根據 $value 和 $key 從 items 中篩選
return new static(Arr::pluck($this->items, $value, $key));
}
/**
* Run a map over each of the items.
*
* @param callable $callback
* @return static
*/
public function map(callable $callback)
{
// 取出鍵名
$keys = array_keys($this->items);
// 將數組 鍵值和鍵名 傳入回調函數$callback中處理
$items = array_map($callback, $this->items, $keys);
return new static(array_combine($keys, $items));
}
/**
* Run a dictionary map over the items.
*
* The callback should return an associative array with a single key/value pair.
*
* @param callable $callback
* @return static
*/
public function mapToDictionary(callable $callback)
{
$dictionary = [];
foreach ($this->items as $key => $item) {
$pair = $callback($item, $key);
$key = key($pair);
$value = reset($pair);
if (! isset($dictionary[$key])) {
$dictionary[$key] = [];
}
$dictionary[$key][] = $value;
}
return new static($dictionary);
}
/**
* Run an associative map over each of the items.
*
* The callback should return an associative array with a single key/value pair.
*
* @param callable $callback
* @return static
*/
public function mapWithKeys(callable $callback)
{
$result = [];
foreach ($this->items as $key => $value) {
$assoc = $callback($value, $key);
foreach ($assoc as $mapKey => $mapValue) {
$result[$mapKey] = $mapValue;
}
}
return new static($result);
}
/**
* Merge the collection with the given items.
*和並一個元素到數組
* @param mixed $items
* @return static
*/
public function merge($items)
{
return new static(array_merge($this->items, $this->getArrayableItems($items)));
}
/**
* Recursively merge the collection with the given items.
*
* @param mixed $items
* @return static
*/
public function mergeRecursive($items)
{
return new static(array_merge_recursive($this->items, $this->getArrayableItems($items)));
}
/**
* Create a collection by using this collection for keys and another for its values.
*創建一個新的collection對象，用本實例的中的數組做鍵名，$values做鍵值
* @param mixed $values
* @return static
*/
public function combine($values)
{
return new static(array_combine($this->all(), $this->getArrayableItems($values)));
}
/**
* Union the collection with the given items.
*合併元素到當前collection對象
* @param mixed $items
* @return static
*/
public function union($items)
{
return new static($this->items + $this->getArrayableItems($items));
}
/**
* Create a new collection consisting of every n-th element.
*取出部分元素組成新數組，規則爲，每隔 $step 個元素取出一個
* @param int $step
* @param int $offset
* @return static
*/
public function nth($step, $offset = 0)
{
$new = [];
$position = 0;
foreach ($this->items as $item) {
if ($position % $step === $offset) {
$new[] = $item;
}
$position++;
}
return new static($new);
}
/**
* Get the items with the specified keys.
*取出 特定 鍵名 的元素，返回一個新的集合對象
* @param mixed $keys
* @return static
*/
public function only($keys)
{
if (is_null($keys)) {
return new static($this->items);
}
if ($keys instanceof Enumerable) {
$keys = $keys->all();
}
$keys = is_array($keys) ? $keys : func_get_args();
return new static(Arr::only($this->items, $keys));
}
/**
* Get and remove the last item from the collection.
*彈出最後一個元素
* @return mixed
*/
public function pop()
{
return array_pop($this->items);
}
/**
* Push an item onto the beginning of the collection.
*壓入一個元素
* @param mixed $value
* @param mixed $key
* @return $this
*/
public function prepend($value, $key = null)
{
$this->items = Arr::prepend($this->items, $value, $key);
return $this;
}
/**
* Push one or more items onto the end of the collection.
*在數組後面新增一個或多個元素
* @param mixed $values [optional]
* @return $this
*/
public function push(...$values)
{
foreach ($values as $value) {
$this->items[] = $value;
}
return $this;
}
/**
* Push all of the given items onto the collection.
*將$source中的元素添加到items後面
* @param iterable $source
* @return static
*/
public function concat($source)
{
$result = new static($this);
foreach ($source as $item) {
$result->push($item);
}
return $result;
}
/**
* Get and remove an item from the collection.
*
* @param mixed $key
* @param mixed $default
* @return mixed
*/
public function pull($key, $default = null)
{
return Arr::pull($this->items, $key, $default);
}
/**
* Put an item in the collection by key.
*
* @param mixed $key
* @param mixed $value
* @return $this
*/
public function put($key, $value)
{
$this->offsetSet($key, $value);
return $this;
}
/**
* Get one or a specified number of items randomly from the collection.
*
* @param int|null $number
* @return static|mixed
*
* @throws \InvalidArgumentException
*/
public function random($number = null)
{
if (is_null($number)) {
return Arr::random($this->items);
}
return new static(Arr::random($this->items, $number));
}
/**
* Reduce the collection to a single value.
*
* @param callable $callback
* @param mixed $initial
* @return mixed
*/
public function reduce(callable $callback, $initial = null)
{
return array_reduce($this->items, $callback, $initial);
}
/**
* Replace the collection items with the given items.
*
* @param mixed $items
* @return static
*/
public function replace($items)
{
return new static(array_replace($this->items, $this->getArrayableItems($items)));
}
/**
* Recursively replace the collection items with the given items.
*
* @param mixed $items
* @return static
*/
public function replaceRecursive($items)
{
return new static(array_replace_recursive($this->items, $this->getArrayableItems($items)));
}
/**
* Reverse items order.
*
* @return static
*/
public function reverse()
{
return new static(array_reverse($this->items, true));
}
/**
* Search the collection for a given value and return the corresponding key if successful.
*
* @param mixed $value
* @param bool $strict
* @return mixed
*/
public function search($value, $strict = false)
{
if (! $this->useAsCallable($value)) {
return array_search($value, $this->items, $strict);
}
foreach ($this->items as $key => $item) {
if ($value($item, $key)) {
return $key;
}
}
return false;
}
/**
* Get and remove the first item from the collection.
*
* @return mixed
*/
public function shift()
{
return array_shift($this->items);
}
/**
* Shuffle the items in the collection.
*
* @param int|null $seed
* @return static
*/
public function shuffle($seed = null)
{
return new static(Arr::shuffle($this->items, $seed));
}
/**
* Skip the first {$count} items.
*跳過 前面 $count個數據，返回後面的數組
* @param int $count
* @return static
*/
public function skip($count)
{
return $this->slice($count);
}
/**
* Slice the underlying collection array.
*調用 array_slice 方法 返回數組中部分數據
*
* @param int $offset
* @param int|null $length
* @return static
*/
public function slice($offset, $length = null)
{
return new static(array_slice($this->items, $offset, $length, true));
}
/**
* Split a collection into a certain number of groups.
*
* @param int $numberOfGroups
* @return static
*/
public function split($numberOfGroups)
{
if ($this->isEmpty()) {
return new static;
}
$groups = new static;
$groupSize = floor($this->count() / $numberOfGroups);
$remain = $this->count() % $numberOfGroups;
$start = 0;
for ($i = 0; $i < $numberOfGroups; $i++) {
$size = $groupSize;
if ($i < $remain) {
$size++;
}
if ($size) {
$groups->push(new static(array_slice($this->items, $start, $size)));
$start += $size;
}
}
return $groups;
}
/**
* Chunk the collection into chunks of the given size.
*
* @param int $size
* @return static
*/
public function chunk($size)
{
if ($size <= 0) {
return new static;
}
$chunks = [];
foreach (array_chunk($this->items, $size, true) as $chunk) {
$chunks[] = new static($chunk);
}
return new static($chunks);
}
/**
* Sort through each item with a callback.
*對元素進行排序，排序規則爲根據鍵值大小升序或者降序
* @param callable|null $callback
* @return static
*/
public function sort($callback = null)
{
$items = $this->items;
// 若 callback 是可調用的結構，則使用用戶自定義的排序規則
$callback && is_callable($callback)
? uasort($items, $callback)
: asort($items, $callback);
return new static($items);
}
/**
* Sort items in descending order.
* 對數組進行倒序排序
* @param int $options
* @return static
*/
public function sortDesc($options = SORT_REGULAR)
{
$items = $this->items;
arsort($items, $options);
return new static($items);
}
/**
* Sort the collection using the given callback.
*用給定的 $callback參數 對items進行排序
* @param callable|string $callback
* @param int $options
* @param bool $descending
* @return static
*/
public function sortBy($callback, $options = SORT_REGULAR, $descending = false)
{
$results = [];
// 處理 $callback 參數，返回一個閉包
$callback = $this->valueRetriever($callback);
// First we will loop through the items and get the comparator from a callback
// function which we were given. Then, we will sort the returned values and
// and grab the corresponding values for the sorted keys from this array.
foreach ($this->items as $key => $value) {
$results[$key] = $callback($value, $key);
}
$descending ? arsort($results, $options)
: asort($results, $options);
// Once we have sorted all of the keys in the array, we will loop through them
// and grab the corresponding model so we can set the underlying items list
// to the sorted version. Then we'll just return the collection instance.
foreach (array_keys($results) as $key) {
$results[$key] = $this->items[$key];
}
return new static($results);
}
/**
* Sort the collection in descending order using the given callback.
*
* @param callable|string $callback
* @param int $options
* @return static
*/
public function sortByDesc($callback, $options = SORT_REGULAR)
{
return $this->sortBy($callback, $options, true);
}
/**
* Sort the collection keys.
*根據鍵名排序
* @param int $options
* @param bool $descending
* @return static
*/
public function sortKeys($options = SORT_REGULAR, $descending = false)
{
$items = $this->items;
$descending ? krsort($items, $options) : ksort($items, $options);
return new static($items);
}
/**
* Sort the collection keys in descending order.
*根據鍵名倒序排序
* @param int $options
* @return static
*/
public function sortKeysDesc($options = SORT_REGULAR)
{
return $this->sortKeys($options, true);
}
/**
* Splice a portion of the underlying collection array.
*從數組中移除元素，並用新元素取代它
* @param int $offset
* @param int|null $length
* @param mixed $replacement
* @return static
*/
public function splice($offset, $length = null, $replacement = [])
{
if (func_num_args() === 1) {
return new static(array_splice($this->items, $offset));
}
return new static(array_splice($this->items, $offset, $length, $replacement));
}
/**
* Take the first or last {$limit} items.
* 取出前面或者後面幾個元素
* @param int $limit
* @return static
*/
public function take($limit)
{
if ($limit < 0) {
return $this->slice($limit, abs($limit));
}
return $this->slice(0, $limit);
}
/**
* Transform each item in the collection using a callback.
*用一個 callable 類型變量處理本對象items屬性中的數據，和map不同，map返回一個包含處理後數據的新實例
* @param callable $callback
* @return $this
*/
public function transform(callable $callback)
{
$this->items = $this->map($callback)->all();
return $this;
}
/**
* Reset the keys on the underlying array.
* 重建鍵名，被返回的數組將使用數值鍵，從 0 開始並以 1 遞增。
* @return static
*/
public function values()
{
return new static(array_values($this->items));
}
/**
* Zip the collection together with one or more arrays.
*將新元素壓入數組
* e.g. new Collection([1, 2, 3])->zip([4, 5, 6]);
* => [[1, 4], [2, 5], [3, 6]]
*
* @param mixed ...$items
* @return static
*/
public function zip($items)
{
// 處理每一個參數，將每個參數轉成數組
$arrayableItems = array_map(function ($items) {
return $this->getArrayableItems($items);
}, func_get_args());
// 作爲call_user_func_array函數調用的參數
$params = array_merge([function () {
return new static(func_get_args());
}, $this->items], $arrayableItems);
return new static(call_user_func_array('array_map', $params));
}
/**
* Pad collection to the specified length with a value.
* 將指定數量的某元素插入到數組中
*
* @param int $size
* @param mixed $value
* @return static
*/
public function pad($size, $value)
{
return new static(array_pad($this->items, $size, $value));
}
/**
* Get an iterator for the items.
*獲取一個迭代器
* @return \ArrayIterator
*/
public function getIterator()
{
return new ArrayIterator($this->items);
}
/**
* Count the number of items in the collection.
*
* @return int
*/
public function count()
{
return count($this->items);
}
/**
* Add an item to the collection.
*
* @param mixed $item
* @return $this
*/
public function add($item)
{
$this->items[] = $item;
return $this;
}
/**
* Get a base Support collection instance from this collection.
*返回一個 Illuminate\Support\Collection 對象
* @return \Illuminate\Support\Collection
*/
public function toBase()
{
return new self($this);
}
/**
* Determine if an item exists at an offset.
*接口ArrayAccess實現方法
* @param mixed $key
* @return bool
*/
public function offsetExists($key)
{
return array_key_exists($key, $this->items);
}
/**
* Get an item at a given offset.
*接口ArrayAccess實現方法
* @param mixed $key
* @return mixed
*/
public function offsetGet($key)
{
return $this->items[$key];
}
/**
* Set the item at a given offset.
*接口ArrayAccess實現方法，設置元素
* @param mixed $key
* @param mixed $value
* @return void
*/
public function offsetSet($key, $value)
{
if (is_null($key)) {
$this->items[] = $value;
} else {
$this->items[$key] = $value;
}
}
/**
* Unset the item at a given offset.
*接口ArrayAccess實現方法，刪除數組元素
* @param string $key
* @return void
*/
public function offsetUnset($key)
{
unset($this->items[$key]);
}
}