php教程

iterator_to_array

(PHP 5 >= 5.1.0, PHP 7)

iterator_to_array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

Example #1 iterator_to_array() example

<?php
$iterator 
= new ArrayIterator(array('recipe'=>'pancakes''egg''milk''flour'));
var_dump(iterator_to_array($iteratortrue));
var_dump(iterator_to_array($iteratorfalse));
?>

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"
}

User Contributed Notes

enelar at develop-project dot ru 22-Jan-2017 04:26
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;
}
Harry Willis 07-Jun-2015 09:21
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.
joksnet at gmail dot com 26-Oct-2014 08:36
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
jerome at yazo dot net 09-Dec-2008 10:42
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"
)
chad 0x40 herballure 0x2e com 27-Mar-2008 06:23
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.

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