如何在 PHP 数组中递归运行 array_filter？

How to run array_filter recursively in a PHP array?

提问by pepe

Given the following array $mm

给定以下数组 $mm

Array
(
    [147] => Array
        (
            [pts_m] => 
            [pts_mreg] => 1
            [pts_cg] => 1
        )    
    [158] => Array
        (
            [pts_m] => 
            [pts_mreg] => 
            [pts_cg] => 0
        )

    [159] => Array
        (
            [pts_m] => 
            [pts_mreg] => 1
            [pts_cg] => 1
        )

)

When I run count(array_filter($mm))I get 3as result since it is not recursive.

当我运行时，count(array_filter($mm))我得到3结果，因为它不是递归的。

count(array_filter($mm), COUNT_RECURSIVE)also will not do because I actually need to run the array_filterrecursively, and then count its result.

count(array_filter($mm), COUNT_RECURSIVE)也不会这样做，因为我实际上需要array_filter递归运行，然后计算其结果。

So my question is: how do I recursively run array_filter($mm)in this case? My expected result here would be 4.

所以我的问题是：array_filter($mm)在这种情况下我如何递归运行？我在这里的预期结果是4.

Please note that I am not using any callback so I can exclude false, null and empty.

请注意，我没有使用任何回调，因此我可以排除 false、null 和 empty。

回答by Francois Deschenes

From the PHP array_filterdocumentation:

从PHParray_filter文档：

//This function filters an array and remove all null values recursively. 

<?php 
  function array_filter_recursive($input) 
  { 
    foreach ($input as &$value) 
    { 
      if (is_array($value)) 
      { 
        $value = array_filter_recursive($value); 
      } 
    } 

    return array_filter($input); 
  } 
?> 

//Or with callback parameter (not tested) : 

<?php 
  function array_filter_recursive($input, $callback = null) 
  { 
    foreach ($input as &$value) 
    { 
      if (is_array($value)) 
      { 
        $value = array_filter_recursive($value, $callback); 
      } 
    } 

    return array_filter($input, $callback); 
  } 
?>

回答by KingCrunch

Should work

应该管用

$count = array_sum(array_map(function ($item) {
  return ((int) !is_null($item['pts_m'])
       + ((int) !is_null($item['pts_mreg'])
       + ((int) !is_null($item['pts_cg']);
}, $array);

or maybe

或者可能

$count = array_sum(array_map(function ($item) {
  return array_sum(array_map('is_int', $item));
}, $array);

There are definitely many more possible solutions. If you want to use array_filter()(without callback) remember, that it treats 0as falsetoo and therefore it will removeany 0-value from the array.

肯定有更多可能的解决方案。如果你想使用array_filter()（没有回调）记住，它把0为false过，因此它会删除任何0从数组-值。

If you are using PHP in a pre-5.3 version, I would use a foreach-loop

如果您在 5.3 之前的版本中使用 PHP，我会使用foreach-loop

$count = 0;
foreach ($array as $item) {
  $count += ((int) !is_null($item['pts_m'])
          + ((int) !is_null($item['pts_mreg'])
          + ((int) !is_null($item['pts_cg']);
}

---

---

Update

更新

Regarding the comment below:

关于下面的评论：

Thx @kc I actually want the method to remove false, 0, empty etc

Thx @kc 我实际上希望该方法删除 false、0、empty 等

When this is really only, what you want, the solution is very simple too. But now I don't know, how to interpret

当这真的只是你想要的时候，解决方案也很简单。但现在我不知道，如何解释

My expected result here would be 5.

我在这里的预期结果是 5。

Anyway, its short now :)

无论如何，它现在很短:)

$result = array_map('array_filter', $array);
$count = array_map('count', $result);
$countSum = array_sum($count);

The resulting array looks like

结果数组看起来像

Array
(
[147] => Array
    (
        [pts_mreg] => 1
        [pts_cg] => 1
    )    
[158] => Array
    (
    )

[159] => Array
    (
        [pts_mreg] => 1
        [pts_cg] => 1
    )

)

回答by Eugen Mihailescu

A better alternative

更好的选择

One implementation that always worked for me is this one:

一直对我有用的一种实现是这样的：

function filter_me(&$array) {
    foreach ( $array as $key => $item ) {
        is_array ( $item ) && $array [$key] = filter_me ( $item );
        if (empty ( $array [$key] ))
            unset ( $array [$key] );
    }
    return $array;
}

I notice that someone had created a similar function except that this one presents, in my opinion, few advantages:

我注意到有人创建了一个类似的函数，但在我看来，这个函数没有什么优势：

1. you pass an array as reference (not its copy) and thus the algorithm is memory-friendly
2. no additional calls to array_filter which in reality involves:
   • the use of stack, ie. additional memory
   • some other operations, ie. CPU cycles

1. 你传递一个数组作为引用（而不是它的副本），因此该算法是内存友好的
2. 没有对 array_filter 的额外调用，这实际上涉及：
   • 堆栈的使用，即。额外的内存
   • 其他一些操作，即。CPU周期

Benchmarks

基准

1. A 64MB array
   • filter_mefunction finished in 0.8s AND the PHP allocated memory before starting the function was 65MB, when function returned it was 39.35MB !!!
   • array_filter_recursivefunction recommended above by Francois Deschenes had no chance; after 1s PHP Fatal error: Allowed memory size of 134217728 bytes exhausted
2. A 36MB array
   • filter_mefunction finished in 0.4s AND the PHP allocated memory before starting the function was 36.8MB, when function returned it was 15MB !!!
   • array_filter_recursivefunction succeeded this time in 0.6s and memory before/after was quite the same

1. 一个 64MB 的阵列
   • filter_me函数在 0.8秒内完成，并且 PHP 在函数启动前分配的内存为 65MB，当函数返回时为 39.35MB !!!
   • 上面 Francois Deschenes 推荐的array_filter_recursive函数没有机会；1 秒后 PHP 致命错误：允许的内存大小为 134217728 字节已用完
2. 一个 36MB 的阵列
   • filter_me函数在0.4 秒内完成，并且 PHP 在函数启动前分配的内存为 36.8MB，当函数返回时为 15MB !!!
   • array_filter_recursive函数在 0.6秒内成功，前后内存完全相同

I hope it helps.

我希望它有帮助。

回答by helpse

This function effectively applies filter_recursive with a provided callback

此函数通过提供的回调有效地应用 filter_recursive

class Arr {

    public static function filter_recursive($array, $callback = NULL)
    {
        foreach ($array as $index => $value)
        {
            if (is_array($value))
            {
                $array[$index] = Arr::filter_recursive($value, $callback);
            }
            else
            {
                $array[$index] = call_user_func($callback, $value);
            }

            if ( ! $array[$index])
            {
                unset($array[$index]);
            }
        }

        return $array;
    }

}

And you'd use it this way:

你会这样使用它：

Arr::filter_recursive($my_array, $my_callback);

This might help someone

这可能会帮助某人

回答by ling

I needed an array filter recursive function that would walk through all nodes (including arrays, so that we have the possibility to discard entire arrays), and so I came up with this:

我需要一个数组过滤递归函数来遍历所有节点（包括数组，以便我们有可能丢弃整个数组），所以我想出了这个：

    public static function filterRecursive(array $array, callable $callback): array
    {
        foreach ($array as $k => $v) {
            $res = call_user_func($callback, $v);
            if (false === $res) {
                unset($array[$k]);
            } else {
                if (is_array($v)) {
                    $array[$k] = self::filterRecursive($v, $callback);
                }
            }
        }

        return $array;
    }

See more examples here: https://github.com/lingtalfi/Bat/blob/master/ArrayTool.md#filterrecursive

在此处查看更多示例：https: //github.com/lingtalfi/Bat/blob/master/ArrayTool.md#filterrecursive

回答by Jrod

<?php

$mm = array
(
    147 => array
        (
            "pts_m" => "",
            "pts_mreg" => 1,
            "pts_cg" => 1
        ) ,
    158 => array
        (
            "pts_m" => null ,
            "pts_mreg" => null,
            "pts_cg" => 0
        ),

    159 => array
        (
            "pts_m" => "",
            "pts_mreg" => 1,
            "pts_cg" => 1
        )

);

$count = 0;
foreach ($mm as $m) {
    foreach ($m as $value) {
        if($value !== false && $value !== "" && $value !== null) {
            $count++;
        }
    }
}
echo $count;
?>