iterator_to_array()
(PHP 5 >= 5.1.0, PHP 7)
将迭代器中的元素拷贝到数组
说明
iterator_to_array(Traversable$iterator[,bool $use_keys= true]): array
将迭代器中的元素拷贝到数组。
参数
- $iterator
被拷贝的迭代器。
- $use_keys
是否使用迭代器元素键作为索引。
返回值
一个数组,包含迭代器中的元素。
更新日志
版本 | 说明 |
---|---|
5.2.1 | 添加了$use_keys参数。 |
范例
iterator_to_array() example
<?php $iterator = new ArrayIterator(array('recipe'=>'pancakes', 'egg', 'milk', 'flour')); var_dump(iterator_to_array($iterator, true)); var_dump(iterator_to_array($iterator, false)); ?>
以上例程会输出:
array(4) { ["recipe"]=> string(8) "pancakes" [0]=> string(3) "egg" [1]=> string(4) "milk" [2]=> string(5) "flour" } array(4) { [0]=> string(8) "pancakes" [1]=> string(3) "egg" [2]=> string(4) "milk" [3]=> string(5) "flour" }
To generate an deep array from nested iterators: <?php function iterator_to_array_deep(\Traversable $iterator, $use_keys = true) { $array = array(); foreach ($iterator as $key => $value) { if ($value instanceof \Iterator) { $value = iterator_to_array_deep($value, $use_keys); } if ($use_keys) { $array[$key] = $value; } else { $array[] = $value; } } return $array; } ?> I use it to test an iterator: https://gist.github.com/jm42/cb328106f393eeb28751
Using the boolean param : <?php $first = new ArrayIterator( array('k1' => 'a' , 'k2' => 'b', 'k3' => 'c', 'k4' => 'd') ); $second = new ArrayIterator( array( 'k1' => 'X', 'k2' => 'Y', 'Z' ) ); $combinedIterator= new AppendIterator(); $combinedIterator->append( $first ); $combinedIterator->append( $second ); var_dump( iterator_to_array($combinedIterator, false) ); ?> will output : array(7) ( [0]=> string(1) "a" [1]=> string(1) "b" [2]=> string(1) "c" [3]=> string(1) "d" [4]=> string(1) "X" [5]=> string(1) "Y" [6]=> string(1) "Z" ) <?php var_dump( iterator_to_array($combinedIterator, true) ); ?> will output (since keys would merge) : array(5) ( ["k1"]=> string(1) "X" ["k2"]=> string(1) "Y" ["k3"]=> string(1) "c" ["k4"]=> string(1) "d" [0]=> string(1) "Z" )
Generator approach function scandir_deep($dir) { foreach (scandir($dir) as $key => $value) if (in_array($value, [".",".."])) continue; else if (is_dir($dir . DIRECTORY_SEPARATOR . $value)) yield $value => scandir_deep($dir . DIRECTORY_SEPARATOR . $value); else yield $value; }
When using iterator_to_array() on an SplObjectStorage object, it's advisable to set $use_keys to false. The resulting array is identical, since the iterator keys produced by SplObjectStorage::key() are always integers from 0 to (COUNT-1). Passing $use_keys=false cuts out the unnecessary calls to SplObjectStorage::key(), giving a slight performance advantage.
The use_keys parameter was added in one of the 5.2.x releases; it defaults to TRUE. This matches the behavior in PHP 5.1.6, which lacks this parameter.