如何在 PHP 中将多维数组“展平”为简单数组？
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How to "flatten" a multi-dimensional array to simple one in PHP?
提问by Adriana
It's probably beginner question but I'm going through documentation for longer time already and I can't find any solution. I thought I could use implode for each dimension and then put those strings back together with str_splitto make new simple array. However I never know if the join pattern isn't also in values and so after doing str_splitmy original values could break.
这可能是初学者的问题，但我已经阅读了更长时间的文档，但找不到任何解决方案。我想我可以对每个维度使用内爆，然后将这些字符串放回一起str_split以创建新的简单数组。但是，我永远不知道连接模式是否也在值中，因此在执行str_split我的原始值之后可能会中断。
Is there something like combine($array1, $array2)for arrays inside of multi-dimensional array?
combine($array1, $array2)多维数组中的数组是否有类似的东西？
采纳答案by Luc M
<?php
$aNonFlat = array(
1,
2,
array(
3,
4,
5,
array(
6,
7
),
8,
9,
),
10,
11
);
$objTmp = (object) array('aFlat' => array());
array_walk_recursive($aNonFlat, create_function('&$v, $k, &$t', '$t->aFlat[] = $v;'), $objTmp);
var_dump($objTmp->aFlat);
/*
array(11) {
[0]=>
int(1)
[1]=>
int(2)
[2]=>
int(3)
[3]=>
int(4)
[4]=>
int(5)
[5]=>
int(6)
[6]=>
int(7)
[7]=>
int(8)
[8]=>
int(9)
[9]=>
int(10)
[10]=>
int(11)
}
*/
?>
Tested with PHP 5.5.9-1ubuntu4.24 (cli) (built: Mar 16 2018 12:32:06)
使用 PHP 5.5.9-1ubuntu4.24 (cli) 测试（构建时间：2018 年 3 月 16 日 12:32:06）
回答by Prasanth Bendra
$array = your array
$result = call_user_func_array('array_merge', $array);
echo "<pre>";
print_r($result);
REF: http://php.net/manual/en/function.call-user-func-array.php
参考：http: //php.net/manual/en/function.call-user-func-array.php
Here is another solution (works with multi-dimensional array) :
这是另一个解决方案（适用于多维数组）：
function array_flatten($array) {
$return = array();
foreach ($array as $key => $value) {
if (is_array($value)){ $return = array_merge($return, array_flatten($value));}
else {$return[$key] = $value;}
}
return $return;
}
$array = Your array
$result = array_flatten($array);
echo "<pre>";
print_r($result);
回答by Arnold Roa
This is a one line, SUPER easy to use:
这是一行，超级好用：
$result = array();
array_walk_recursive($original_array,function($v) use (&$result){ $result[] = $v; });
It is very easy to understand, inside the anonymous function/closure. $vis the value of your $original_array.
在匿名函数/闭包中很容易理解。$v是你的价值$original_array。
回答by upallnite
// $array = your multidimensional array
$flat_array = array();
foreach(new RecursiveIteratorIterator(new RecursiveArrayIterator($array)) as $k=>$v){
$flat_array[$k] = $v;
}
Also documented: http://www.phpro.org/examples/Flatten-Array.html
回答by Josh Johnson
If you specifically have an array of arrays that doesn't go further than one level deep (a use case I find common) you can get away with array_mergeand the splat operator.
如果您特别有一个数组数组，其深度不超过一个级别（我发现一个用例很常见），您可以使用array_mergesplat 运算符。
<?php
$notFlat = [[1,2],[3,4]];
$flat = array_merge(...$notFlat);
var_dump($flat);
Output:
输出：
array(4) {
[0]=>
int(1)
[1]=>
int(2)
[2]=>
int(3)
[3]=>
int(4)
}
The splat operator effectively changes the array of arrays to a list of arrays as arguments for array_merge.
splat 运算符有效地将数组数组更改为数组列表作为 的参数array_merge。
回答by chaos
function flatten_array($array, $preserve_keys = 0, &$out = array()) {
# Flatten a multidimensional array to one dimension, optionally preserving keys.
#
# $array - the array to flatten
# $preserve_keys - 0 (default) to not preserve keys, 1 to preserve string keys only, 2 to preserve all keys
# $out - internal use argument for recursion
foreach($array as $key => $child)
if(is_array($child))
$out = flatten_array($child, $preserve_keys, $out);
elseif($preserve_keys + is_string($key) > 1)
$out[$key] = $child;
else
$out[] = $child;
return $out;
}
回答by SamGoody
Another method from PHP's user comments(simplified) and here:
function array_flatten_recursive($array) {
if (!$array) return false;
$flat = array();
$RII = new RecursiveIteratorIterator(new RecursiveArrayIterator($array));
foreach ($RII as $value) $flat[] = $value;
return $flat;
}
The big benefit of this method is that it tracks the depth of the recursion, should you need that while flattening.
This will output:
这种方法的最大好处是它可以跟踪递归的深度，如果您在展平时需要的话。
这将输出：
$array = array(
'A' => array('B' => array( 1, 2, 3)),
'C' => array(4, 5)
);
print_r(array_flatten_recursive($array));
#Returns:
Array (
[0] => 1
[1] => 2
[2] => 3
[3] => 4
[4] => 5
)
回答by hisa_py
In PHP>=5.3 and based on Luc M's answer (the first one) you can make use of closures like this
在 PHP>=5.3 中并基于 Luc M 的回答（第一个），您可以使用这样的闭包
array_walk_recursive($aNonFlat, function(&$v, $k, &$t){$t->aFlat[] = $v;}, $objTmp);
I love this because I don't have to surround the function's code with quotes like when using create_function()
我喜欢这个，因为我不必像使用 create_function() 那样用引号将函数的代码括起来
回答by phihag
A non-recursive solution (but order-destroying):
非递归解决方案（但破坏订单）：
function flatten($ar) {
$toflat = array($ar);
$res = array();
while (($r = array_shift($toflat)) !== NULL) {
foreach ($r as $v) {
if (is_array($v)) {
$toflat[] = $v;
} else {
$res[] = $v;
}
}
}
return $res;
}
回答by kelunik
With PHP 7, you can use generators and generator delegation (yield from) to flatten an array:
在 PHP 7 中，您可以使用生成器和生成器委托 ( yield from) 来展平数组：
function array_flatten_iterator (array $array) {
foreach ($array as $value) {
if (is_array($value)) {
yield from array_flatten_iterator($value);
} else {
yield $value;
}
}
}
function array_flatten (array $array) {
return iterator_to_array(array_flatten_iterator($array), false);
}
Example:
例子：
$array = [
1,
2,
[
3,
4,
5,
[
6,
7
],
8,
9,
],
10,
11,
];
var_dump(array_flatten($array));
