基于键从多维数组中删除元素

Question

How can I delete an element from a multi-dimensional array given a key?

I am hoping for this to be greedy so that it deletes all elements in an array that match the keys I pass in. I have this so far where I can traverse a multi-dimensional array but I can't unset the key I need to because I don't have a reference to it!

function traverseArray($array, $keys)
{ 
    foreach($array as $key=>$value)
    { 
        if(is_array($value))
        { 
            traverseArray($value); 

        } else {

            if(in_array($key, $keys))
           {                    
                //unset(what goes here?) 

            }

        } 
    }

}

Answer 1

The following code works (and doesn't use deprecated stuff), just tested it:

function traverseArray(&$array, $keys) { 
  foreach ($array as $key => &$value) { 
    if (is_array($value)) { 
      traverseArray($value, $keys); 
    } else {
      if (in_array($key, $keys)){
        unset($array[$key]);
      }
    } 
  }
}

Answer 2

You could use pass by reference, declare your function like this:

function traverseArray(&$array, $keys)
{ 
    foreach($array as $key=>$value)
    { 
        if(is_array($value))
        { 
            traverseArray($value, $keys); 
        }else{
            if(in_array($key, $keys)){
                unset($array[$key]);
            }
        } 
    }
}

then you can unset the key and it will vanish from the original passed value too since the $array in the function is merely a pointer to the array you passed so it updates that array.

unset($array[$key]);

For more information check the php documentation on passing by reference

Answer 3

You can do this

unset($array[$key]);

because $array will not be a copy of the original array, just a reference to it, so any modifications will hold.

Also, you have a small bug in your snippet: when you make the recursive call, you forget the pass the $keys parameter.

Answer 4

并且不要忘记修改foreach：

foreach($array as $key=>&$value)