PHP - 递归多维数组迭代器 [英] PHP - Recursive Multidimension Array iterator

问题描述

我正在尝试编写一个递归数组迭代器函数，该函数将返回由$needle"指定的所有集合的结果集.$needle = key

I'm trying to write a recursive array iterator function in which the function will return a result set of all sets that are specified by '$needle'. Where $needle = key

这是我的功能:

function recursive($needle, $array, $holder = array()) {
    foreach ($array as $key => $value) {
        if (gettype($value) == 'array') {
            if ($key != $needle) {
                recursive($needle, $value);
            } elseif ($key == $needle) {
                if (!empty($value)) {
                    array_push($holder, $value);
                }
            }
        }
    }
    return $holder;
}

但是如果我没有指定 !empty($value)，我不会得到所有的结果，而是得到一些空的结果，尽管输入数组没有任何空集.我做错了什么?

But I'm not getting all the results back and instead get a few empty results, if I don't specify the !empty($value), although the input array does not have any empty sets. What am I doing wrong?

推荐答案

你不需要重新发明轮子，因为 PHP 有标准的 递归迭代器 API:

You don't need to reinvent the wheel since PHP has standard Recursive Iterator API:

//$array is your multi-dimensional array
$result   = [];
$search   = 'foo';
$iterator = new RecursiveIteratorIterator(
    new RecursiveArrayIterator(
        $array,
        RecursiveArrayIterator::CHILD_ARRAYS_ONLY
    )
); 

foreach($iterator as $key=>$value)
{
   if($search==$key && $value!=='')
   {
      $result[] = $value;
   }
}

-注意，因为您正在按键搜索值-通常情况下 $value 将包含整个小节.

-note, that, since you're searching for value by key - in common case $value will hold entire subsection.

如果你想在你自己的递归函数中做到这一点，这里有一个:

If you want to do this in your own recursive function, here's one:

function recursive($needle, $array, $holder = []) 
{
    $holder = [];
    foreach($array as $key=>$value)
    {
       if($key===$needle && $value!=='')
       {
          $holder = array_merge($holder, [$value]);
       }
       if(is_array($value))
       {
          $holder = array_merge($holder, recursive($needle, $value, $holder));
       }
    }
    return $holder;
}

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