在没有很多循环的PHP中访问嵌套数组

问题描述：

Consider the following:

$dropdown = array (
    "unitofmeasure" => array (
        "m"     => "meters",
        "ft"    => "feet"
    ),
    "facing_direction" => array (
        "0"     => array ("West","North-West","North","North-East","East","South-East"),
        "1"     => array("South","South-West")
    )
    .... 
)

Assume there are n number of sub arrays, not just the two shown above.

Iteration solution:

foreach($dropdown as $key => $val) {
    foreach($val as $k => $v) { 
        foreach($v as $id => $value) {
           //manipulate values here
        }
    }
}

My question is:

is there not a more elegant solution available in PHP?
for example something like foreach($dropdown->children()->children() ...)

_{I know there are a few semi-similar questions on SO but they're slightly different and the answers are mediocre.}

请考虑以下事项： p>

  $ dropdown = array（\  n“unitofmeasure”=＆gt;数组（
“m”=＆gt;“米”，
“ft”=＆gt;“脚”
），
“facing_direction”=＆gt;数组（
“0  “=＆gt;数组（”西“，”西北“，”北“，”东北“，”东“，”东南“），
”1“=＆gt;数组（”南“）  ，“西南”）
）
 .... 
）
  code>  pre> 
 
 假设有 n  em>个子数 数组，不仅仅是上面显示的两个。   p> 
 
 
迭代解决方案： p> 
 
 

  foreach（$ dropdown as $ key =＆gt; $ val）{
 foreach（$ val as $  k =＆gt; $ v）{
 foreach（$ v as $ id =＆gt; $ value）{
 //在此操纵值
} 
} 
} 
  code>  pre>  
 
 我的问题是： p> 
 
 
 
   PHP中没有更优雅的解决方案吗？ strong> 
 
 例如 foreach（$ dropdown-＆gt; children（） - ＆gt; children（）...） code>  p> 
  blockquote> 
 
 
 _{我知道在SO上有一些半相似的问题，但它们略有不同，答案是平庸的。   sub>  p> 
  div>}

答

Yes, I personally tend to use array_walk_recursive with a closure(if you're using PHP above 5.3).

You can, obviously, also use recursion if you like getting your hands dirty.

I suppose an example is in order:

$array = [ 0 => [0 => [ 0 => 1 ...]]];

$manipulated_array = [];

array_walk_recursive($array, function($value) use (&$manipulated_array)
{
  // do whatever you wish here
});

答

foreach() just expects an array, so if you only need to iterate ONE of those deeply nested arrays, then you can quite easily have

foreach($arr['level1']['level2'][...]['levelGazillion'] as ...)

答

I tend to use recursion in these situations:

function modify_array(&$arr)
{
    if (is_array(arr)) {
        foreach($arr as &$val) {
            modify_array($val);
        }
    } else {
        modify_value($arr);
    }
}

where modify_value(&$val) is whatever you want to do to each non-array child at any arbitrary depth

在没有很多循环的PHP中访问嵌套数组

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