Passing location in subarray as string - php

Question

I have a function that searches a multidimensional array for a key, and returns the path
inside the array to my desired key as a string.
Is there any way I can use this string in php to reach this place in my original array, not to get to the value but to make changes to this specific bracnch of the array?
An example:
$array = array('first_level'=>array(
'second_level'=>array(
'desired_key'=>'value')));
in this example the function will return the string:
'first_level=>second_level=>desired_key'
Is there a way to use this output, or format it differently in order to use it in the following or a similar way?
$res = find_deep_key($array,'needle');
$array[$res]['newkey'] = 'injected value';
Thanks

Answer 1

If the keys path is safe (e.g. not given by the user), you can use eval and do something like:
$k = 'first_level=>second_level=>desired_key';
$k = explode('=>', $k);
$keys = '[\'' . implode('\'][\'', $k) . '\']';
eval('$key = &$array' . $keys . ';');
var_dump($key);

Answer 2

I think you want to do a recursive search in the array for your key? Correct me if i am wrong.
Try this
function recursive_array_search($needle,$haystack) {
foreach($haystack as $key=>$value) {
$current_key=$key;
if($needle===$value OR (is_array($value) && recursive_array_search($needle,$value) !== false)) {
return $current_key;
}
}
return false;
}
Taken from here http://in3.php.net/manual/en/function.array-search.php#91365

Answer 3

You need something like:
find_key_in_array($key, $array, function($foundValue){
// do stuff here with found value, e.g.
return $foundValue * 2;
});
and the implementation would be something like:
function find_key_in_array($key, $array, $callback){
// iterate over array fields recursively till you find desired field, then:
...
$array[$key] = $callback($array[$key]);
}

Answer 4

If you need to append some new sub-array into multidimensional complex array and you know where exactly it should be appended (you have path as a string), this might work (another approach without eval()):
function append_to_subarray_by_path($newkey, $newvalue, $path, $pathDelimiter, &$array) {
$destinationArray = &$array;
foreach (explode($pathDelimiter, $path) as $key) {
if (isset($destinationArray[$key])) {
$destinationArray = &$destinationArray[$key];
} else {
$destinationArray[$newkey] = $newvalue;
}
}
}
$res = find_deep_key($array,'needle');
append_to_subarray_by_path('newkey', 'injected value', $res, '=>', $array);
Of course, it will work only if all keys in path already exist. Otherwise it will append new sub-array into wrong place.

Answer 5

just write a function that takes the string and the array. The function will take the key for each array level and then returns the found object.
such as:
void object FindArray(Array[] array,String key)
{
if(key.Length == 0) return array;
var currentKey = key.Split('=>')[0];
return FindArray(array[currentKey], key.Remove(currentKey));
}