Related
I have a deep multidimensional array that I am needing to extract the value of a specific key. I have found that the array_walk_recursive function will be my best option. I only need the first occurrence.
My array looks like this - (except much more complicated)
Array (
[vehicle info] => Array (
[one] => Array (
[submodel] => LX
[engine] => 2.3
)
[two] => Array (
[color] => blue
[year] => 2007
[wheels] => 4
)
[three] => Array (
[submodel] => LX
[make] => Ford
[model] => F-150
[offroad] => No
)
)
)
The issue here is, submodel is in both one and three. Additionally, the array is not consistent, so I must use array_walk_recursive to search through it for the matching key, then return the value for that key.
Here is my current code -
array_walk_recursive ($array, (function ($item, $key) {
$wanted = "submodel";
if ($key === $wanted) {
echo ("$key is $item");
}
}));
The above returns submodel is LXsubmodel is LX.
Bonus Question!!
How can I search for multiple keys and return the first corresponding value for each of those? I was thinking putting all wanted keys in an array, then do a foreach loop, but don't quite know how to structure this. I am new to php.
array_walk_recursive() is the appropriate native function to call for this task. Keep track of which keys have already been declared in the result array and ensure that they are never overwritten.
Code: (Demo)
$needles = ['submodel', 'offroad'];
$result = [];
array_walk_recursive(
$array,
function($value, $key) use ($needles, &$result) {
if (
in_array($key, $needles)
&& !isset($result[$key])
) {
$result[$key] = "$key is $value";
}
}
);
var_export($result);
Output:
array (
'submodel' => 'submodel is LX',
'offroad' => 'offroad is No',
)
If your application has performance concerns, then the native function becomes less attractive because it will always iterate the entire input array's structure -- even after all sought keys are encountered. If you want to "break early" (short circuit), then you will need to design your own recursive function which will return when all sought keys are found.
Code: (Demo)
$soughtKeys = array_flip(['submodel', 'offroad']);
function earlyReturningRecursion(array $array, array $soughtKeys, array &$result = []): array
{
foreach ($array as $key => $value) {
if (!array_diff_key($soughtKeys, $result)) { // check if result is complete
return $result;
} elseif (is_array($value)) {
earlyReturningRecursion($value, $soughtKeys, $result);
} elseif (isset($soughtKeys[$key]) && !isset($result[$key])) {
$result[$key] = "$key is $value";
}
}
return $result;
}
var_export(earlyReturningRecursion($array, $soughtKeys));
// same output as the first snippet
I would start by setting the values you want to null, and then only saving them if they haven't been found yet, by checking is_null(). I haven't tested this code, but it should look something like this:
$submodel = null;
array_walk_recursive ($array, (function ($item, $key) {
$wanted = "submodel";
if ($key === $wanted && is_null($submodel)) {
echo ("$key is $item");
$submodel = $item;
}
}));
array_walk_recursive() has the defect of not allowing to return matching results however in PHP 7 you could use an anonymous function and a variable to store the matching value.
$matching = null;
$wanted = "submodel";
array_walk_recursive ($array, function ($item, $key) use ($wanted, $matching) {
if (($key === $wanted) && is_null($matching)) {
$matching = $item;
}
});
As far as there is no way to return early from array_walk_recursive(), I'd suggest to create a function to find the first occurrence of $wanted:
$arr = [
'vehicle info' => [
'one' => ['submodel' => 'LX', 'engine' => '2.3'],
'two' => ['color' => 'blue', 'year' => '2007', 'wheels' => '4'],
'three' => ['submodel' => 'LX', 'make' => 'Ford', 'model' => 'F-150', 'offroad' => 'No'],
],
];
function find($needle, $haystack, $found = '')
{
foreach ($haystack as $key => $value) {
if ($found) {
break;
}
if ($key === $needle) {
$found = "{$needle} is {$value}";
break;
}
if (is_array($value)) {
$found = find($needle, $value, $found);
}
}
return $found;
}
$wanted = 'submodel';
$result = find($wanted, $arr);
var_dump($result); // string(14) "submodel is LX"
Live demo
Update: to search for multiple keys you'll need to do it in a loop:
$multiple_keys = array('submodel', 'year');
foreach ($multiple_keys as $wanted) {
var_dump(find($wanted, $arr));
}
// Output:
// string(14) "submodel is LX"
// string(12) "year is 2007"
Live demo
I need some help with another PHP problem I am working on. I won't be posting the exact question, as I'd prefer to try and apply the knowledge I get from here to solve my problem.
First:
I have an associative array. I must loop through the array to find the array values which have keys that begin with a specific string and push both the key and value to an output array.
eg:
- Loop through the below array & push all elements which have a key beginning with "edible_" to an output array:
$assoc_array = array(
'edible_fruit' => 'apple',
'animal' => 'cat',
'edible_veg' => 'pumpkin',
'number' => '23',
'city' => 'Cape Town',
'edible_berry' => 'blueberry',
'color' => 'blue'
);
Would this work?
$result = array();
foreach ($assoc_array as $key => $value) {
if (substr($key, 0, 7) == "edible_") {
array_push($result, $value);
}
}
print_r($result);
Second:
How would I remove "edible_" from the output array's keys? With this second bit I have no idea where to even begin!
Third:
I've managed to figure out the above with all your help, thank you! Now I just need to find out how I would print each element on a new line with a date & timestamp at the end of each line? I've got this (doesn't seem to be working):
while (list($key, $value) = each($output)) {
print_r("$key => $value" . date("y/m/d G.i:s", time()) . "<br>");
}
First of your code will work.
To remove edible_ from the key you could use explode() -
$keyParts = explode('_', $key);
$newKey = $keyParts[1];
You will have to add the new keys to the array, which you're not doing now.
foreach ($assoc_array as $key => $value) {
if (substr($key, 0, 7) == "edible_") {
$keyParts = explode('_', $key);
$newKey = $keyParts[1];
$result[$newKey] = $value;
}
}
This would be my approach:
foreach($assoc_array as $key => $value) {
if(preg_match("/^edible_/",$key)) {
$result[preg_replace("/^edible_/","",$key)] = $value;
}
}
use preg_match to check if the key starts with what you are looking for and use preg_replace to remove the string from the beginning (^) of the key :)
Input ($assoc_array):
Array
(
[edible_fruit] => apple
[animal] => cat
[edible_veg] => pumpkin
[number] => 23
[city] => Cape Town
[edible_berry] => blueberry
[color] => blue
)
Output ($result):
Array
(
[fruit] => apple
[veg] => pumpkin
[berry] => blueberry
)
First: yes, that would work, however I would rewrite it a bit:
foreach ($assoc_array as $key => $value) {
if (strpos($key, 'edible_') === 0) {
$result[] = $value;
}
}
Regarding Second: You are asking how to remove the key from the output array. However you did not even push the key into the output array, you only pushed the value. If you'd like to also push the key, you should do it like this:
$result[$key] = $value;
But since you haven't done that, there's no need to remove the key.
If you however meant removing the edible_ part of the key from the $assoc_array, you'd just need to add a line to the loop and pass the key by reference by adding a &:
foreach ($assoc_array as &$key => $value) {
if (strpos($key, 'edible_') === 0) {
$key = str_replace('edible_', '', $key)
$result[] = $value;
}
}
Edit: As OP told me in comments, she wants to push the key without the edible part. So just do it like this:
foreach ($assoc_array as $key => $value) {
if (strpos($key, 'edible_') === 0) {
$key = str_replace('edible_', '', $key)
$result[$key] = $value;
}
}
This should work for you:
First I remove all elements, which doesn't have edible_ at the start of the key with array_diff_ukey(). After this I simply array_combine() the elements with they keys, where I remove the prefix with array_map() and substr().
<?php
$assoc_array = array('edible_fruit'=>'apple', 'animal'=>'cat', 'edible_veg'=>'pumpkin', 'number'=>'23', 'city'=>'Cape Town', 'edible_berry'=>'blueberry', 'color'=>'blue');
//remove elemnts
$result = array_diff_ukey($assoc_array, ["edible_" => ""], function($k1, $k2){
return substr($k1, 0, 7) == $k2;
});
//change keys
$result = array_combine(
array_map(function($v){
return substr($v, 7);
}, array_keys($result)),
$result);
print_r($result);
?>
output:
Array ( [fruit] => apple [veg] => pumpkin [berry] => blueberry )
You can loop through the array and search if the key has the string that you can eliminate and make your $newArray
<?php
$assoc_array = array('edible_fruit'=>'apple', 'animal'=>'cat', 'edible_veg'=>'pumpkin', 'number'=>'23', 'city'=>'Cape Town', 'edible_berry'=>'blueberry', 'color'=>'blue');
$search = 'edible_';
$newArray = array();
#First and Second Step
foreach($assoc_array as $key => $value) {
if(strpos($key, "edible_") === 0) {
$newArray[substr($key, 7)] = $value;
}
}
print_r($newArray);
echo "<br>\n";
#Third Step
foreach($newArray as $key => $value) {
echo "$key => $value " . date("y/m/d G.i:s", time()) . "<br>\n";
}
Output:
#First and Second Step
Array ( [fruit] => apple [veg] => pumpkin [berry] => blueberry )
#Third Step
fruit => apple 15/04/10 3.02:16
veg => pumpkin 15/04/10 3.02:16
berry => blueberry 15/04/10 3.02:16
Suppose I have an array like this:
$array = array("a","b","c","d","a","a");
and I want to get all the keys that have the value "a".
I know I can get them using a while loop:
while ($a = current($array)) {
if ($a == 'a') {
echo key($array).',';
}
next($array);
}
How can I get them using a foreach loop instead?
I've tried:
foreach ($array as $a) {
if ($a == 'a') {
echo key($array).',';
}
}
and I got
1,1,1,
as the result.
If you would like all of the keys for a particular value, I would suggest using array_keys, using the optional search_value parameter.
$input = array("Foo" => "X", "Bar" => "X", "Fizz" => "O");
$result = array_keys( $input, "X" );
Where $result becomes
Array (
[0] => Foo
[1] => Bar
)
If you wish to use a foreach, you can iterate through each key/value set, adding the key to a new array collection when its value matches your search:
$array = array("a","b","c","d","a","a");
$keys = array();
foreach ( $array as $key => $value )
$value === "a" && array_push( $keys, $key );
Where $keys becomes
Array (
[0] => 0
[1] => 4
[2] => 5
)
You can use the below to print out keys with specific value
foreach ($array as $key=>$val) {
if ($val == 'a') {
echo $key." ";
}
}
here's a simpler filter.
$query = "a";
$result = array_keys(array_filter($array,
function($element)use($query){
if($element==$query) return true;
}
));
use
foreach($array as $key=>$val)
{
//access the $key as key.
}
I need to search and replace inside an associative array.
ex:
$user = "user1"; // I've updated this
$myarray = array("user1" => "search1", "user2" => "search2", "user3" => "search1" ) ;
I want to replace search1 for search4. How can I achieve this?
UPDATE: I forgot to mention that the array has several search1 values and I just want to change the value where the key is == $user. Sorry for not mention this earlier.
$myarray = array("user1" => "search1", "user2" => "search2" );
foreach($myarray as $key => $val)
{
if ($val == 'search1') $myarray[$key] = 'search4';
}
There's a function for this : array_map().
// Using a lamba function, PHP 5.3 required
$newarray = array_map(
function($v) { if ($v == 'search1') $v = 'search4'; return $v; },
$myarray
);
If you don't want to use a lambda function, define a normal function or method and callback to it.
Why not just do
if (isset($myarray[$user])) $myarray[$user] = 'search4';
$user = "user1";
$myarray = array("user1" => "search1", "user2" => "search2", "user3" => "search1" );
foreach($myarray as $key => $val)
{
if ($val == 'search1' and $key == $user )
{
$myarray[$key] = 'search4';
break;
}
}
print_r($myarray);
Prints:
Array
(
[user1] => search4
[user2] => search2
[user3] => search1
)
$originalArray = array( "user1" => "search1" , "user2" => "search2" );
$pattern = 'search1';
$replace = 'search4';
$replacedArray = preg_replace( '/'.$pattern.'/' , $replace , $originalArray );
Fixes the risk mentioned in comment in response to this solution
Updated
Since the post was updated, and I have had chance to get some sleep, I realized my answer was stupid. If you have a given key and you need to change it's value, why iterate over the whole array?
$user = 'user1';
$search = 'search1';
$replace = 'search4';
$array = array('user1' => 'search1', 'user2' => 'search2');
if (isset($array[$user]) && $search === $array[$user]) $array[$user] = $replace;
Similar to #Joseph's method (pretty much the same), but with a few tweaks:
$user = 'user1';
$array = array("user1" => "search1", "user2" => "search2" );
foreach($array as $key => &$value) {
if ($key === $user) {
$value = 'search4';
break; // Stop iterating after key has been found
}
}
Passing by reference is a nicer way to edit inside foreach, and is arguably quicker.
Search and replace inside an associative array or numeric
Replace value in any associative array and array can be any deep
function array_value_replace($maybe_array, $replace_from, $replace_to) {
if (!empty($maybe_array)) {
if (is_array($maybe_array)) {
foreach ($maybe_array as $key => $value) {
$maybe_array[$key] = array_value_replace($value, $replace_from, $replace_to);
}
} else {
if(is_string($maybe_array)){
$maybe_array = str_replace($replace_from, $replace_to, $maybe_array);
}
}
}
return $maybe_array;
}
if you want for particular key then you just add condition for key in previous ans like.
$user = "user1";
$myarray = array("user1" => "search1", "user2" => "search2" );
foreach($myarray as $key => $val)
{
if ($val == 'search1' && $key == $user) $myarray[$key] = 'search4';
}
Using str_replace should work:
$myarray = array("user1" => "search1", "user2" => "search2" ) ;
$newArray = str_replace('search1', 'search4', $myarray);
Following on from Joseph's answer, using preg_replace may enable you to use the code in other situations:
function pregReplaceInArray($pattern,$replacement,$array) {
foreach ($array as $key => $value) {
$array[$key] = preg_replace($pattern,$replacement,$value);
}
return $array;
}
Is there any fast way to get all subarrays where a key value pair was found in a multidimensional array? I can't say how deep the array will be.
Simple example array:
$arr = array(0 => array(id=>1,name=>"cat 1"),
1 => array(id=>2,name=>"cat 2"),
2 => array(id=>3,name=>"cat 1")
);
When I search for key=name and value="cat 1" the function should return:
array(0 => array(id=>1,name=>"cat 1"),
1 => array(id=>3,name=>"cat 1")
);
I guess the function has to be recursive to get down to the deepest level.
Code:
function search($array, $key, $value)
{
$results = array();
if (is_array($array)) {
if (isset($array[$key]) && $array[$key] == $value) {
$results[] = $array;
}
foreach ($array as $subarray) {
$results = array_merge($results, search($subarray, $key, $value));
}
}
return $results;
}
$arr = array(0 => array(id=>1,name=>"cat 1"),
1 => array(id=>2,name=>"cat 2"),
2 => array(id=>3,name=>"cat 1"));
print_r(search($arr, 'name', 'cat 1'));
Output:
Array
(
[0] => Array
(
[id] => 1
[name] => cat 1
)
[1] => Array
(
[id] => 3
[name] => cat 1
)
)
If efficiency is important you could write it so all the recursive calls store their results in the same temporary $results array rather than merging arrays together, like so:
function search($array, $key, $value)
{
$results = array();
search_r($array, $key, $value, $results);
return $results;
}
function search_r($array, $key, $value, &$results)
{
if (!is_array($array)) {
return;
}
if (isset($array[$key]) && $array[$key] == $value) {
$results[] = $array;
}
foreach ($array as $subarray) {
search_r($subarray, $key, $value, $results);
}
}
The key there is that search_r takes its fourth parameter by reference rather than by value; the ampersand & is crucial.
FYI: If you have an older version of PHP then you have to specify the pass-by-reference part in the call to search_r rather than in its declaration. That is, the last line becomes search_r($subarray, $key, $value, &$results).
How about the SPL version instead? It'll save you some typing:
// I changed your input example to make it harder and
// to show it works at lower depths:
$arr = array(0 => array('id'=>1,'name'=>"cat 1"),
1 => array(array('id'=>3,'name'=>"cat 1")),
2 => array('id'=>2,'name'=>"cat 2")
);
//here's the code:
$arrIt = new RecursiveIteratorIterator(new RecursiveArrayIterator($arr));
foreach ($arrIt as $sub) {
$subArray = $arrIt->getSubIterator();
if ($subArray['name'] === 'cat 1') {
$outputArray[] = iterator_to_array($subArray);
}
}
What's great is that basically the same code will iterate through a directory for you, by using a RecursiveDirectoryIterator instead of a RecursiveArrayIterator. SPL is the roxor.
The only bummer about SPL is that it's badly documented on the web. But several PHP books go into some useful detail, particularly Pro PHP; and you can probably google for more info, too.
<?php
$arr = array(0 => array("id"=>1,"name"=>"cat 1"),
1 => array("id"=>2,"name"=>"cat 2"),
2 => array("id"=>3,"name"=>"cat 1")
);
$arr = array_filter($arr, function($ar) {
return ($ar['name'] == 'cat 1');
//return ($ar['name'] == 'cat 1' AND $ar['id'] == '3');// you can add multiple conditions
});
echo "<pre>";
print_r($arr);
?>
Ref: http://php.net/manual/en/function.array-filter.php
Came back to post this update for anyone needing an optimisation tip on these answers, particulary John Kugelman's great answer up above.
His posted function work fine but I had to optimize this scenario for handling a 12 000 row resultset. The function was taking an eternal 8 secs to go through all records, waaaaaay too long.
I simply needed the function to STOP searching and return when match was found. Ie, if searching for a customer_id, we know we only have one in the resultset and once we find the customer_id in
the multidimensional array, we want to return.
Here is the speed-optimised ( and much simplified ) version of this function, for anyone in need. Unlike other version, it can only handle only one depth of array, does not recurse and does away with merging multiple results.
// search array for specific key = value
public function searchSubArray(Array $array, $key, $value) {
foreach ($array as $subarray){
if (isset($subarray[$key]) && $subarray[$key] == $value)
return $subarray;
}
}
This brought down the the task to match the 12 000 records to a 1.5 secs. Still very costly but much more reasonable.
if (isset($array[$key]) && $array[$key] == $value)
A minor imporvement to the fast version.
Here is solution:
<?php
$students['e1003']['birthplace'] = ("Mandaluyong <br>");
$students['ter1003']['birthplace'] = ("San Juan <br>");
$students['fgg1003']['birthplace'] = ("Quezon City <br>");
$students['bdf1003']['birthplace'] = ("Manila <br>");
$key = array_search('Delata Jona', array_column($students, 'name'));
echo $key;
?>
Be careful of linear search algorithms (the above are linear) in multiple dimensional arrays as they have compounded complexity as its depth increases the number of iterations required to traverse the entire array. Eg:
array(
[0] => array ([0] => something, [1] => something_else))
...
[100] => array ([0] => something100, [1] => something_else100))
)
would take at the most 200 iterations to find what you are looking for (if the needle were at [100][1]), with a suitable algorithm.
Linear algorithms in this case perform at O(n) (order total number of elements in entire array), this is poor, a million entries (eg a 1000x100x10 array) would take on average 500,000 iterations to find the needle. Also what would happen if you decided to change the structure of your multidimensional array? And PHP would kick out a recursive algorithm if your depth was more than 100. Computer science can do better:
Where possible, always use objects instead of multiple dimensional arrays:
ArrayObject(
MyObject(something, something_else))
...
MyObject(something100, something_else100))
)
and apply a custom comparator interface and function to sort and find them:
interface Comparable {
public function compareTo(Comparable $o);
}
class MyObject implements Comparable {
public function compareTo(Comparable $o){
...
}
}
function myComp(Comparable $a, Comparable $b){
return $a->compareTo($b);
}
You can use uasort() to utilize a custom comparator, if you're feeling adventurous you should implement your own collections for your objects that can sort and manage them (I always extend ArrayObject to include a search function at the very least).
$arrayObj->uasort("myComp");
Once they are sorted (uasort is O(n log n), which is as good as it gets over arbitrary data), binary search can do the operation in O(log n) time, ie a million entries only takes ~20 iterations to search. As far as I am aware custom comparator binary search is not implemented in PHP (array_search() uses natural ordering which works on object references not their properties), you would have to implement this your self like I do.
This approach is more efficient (there is no longer a depth) and more importantly universal (assuming you enforce comparability using interfaces) since objects define how they are sorted, so you can recycle the code infinitely. Much better =)
$result = array_filter($arr, function ($var) {
$found = false;
array_walk_recursive($var, function ($item, $key) use (&$found) {
$found = $found || $key == "name" && $item == "cat 1";
});
return $found;
});
http://snipplr.com/view/51108/nested-array-search-by-value-or-key/
<?php
//PHP 5.3
function searchNestedArray(array $array, $search, $mode = 'value') {
foreach (new RecursiveIteratorIterator(new RecursiveArrayIterator($array)) as $key => $value) {
if ($search === ${${"mode"}})
return true;
}
return false;
}
$data = array(
array('abc', 'ddd'),
'ccc',
'bbb',
array('aaa', array('yyy', 'mp' => 555))
);
var_dump(searchNestedArray($data, 555));
function in_multi_array($needle, $key, $haystack)
{
$in_multi_array = false;
if (in_array($needle, $haystack))
{
$in_multi_array = true;
}else
{
foreach( $haystack as $key1 => $val )
{
if(is_array($val))
{
if($this->in_multi_array($needle, $key, $val))
{
$in_multi_array = true;
break;
}
}
}
}
return $in_multi_array;
}
I needed something similar, but to search for multidimensional array by value... I took John example and wrote
function _search_array_by_value($array, $value) {
$results = array();
if (is_array($array)) {
$found = array_search($value,$array);
if ($found) {
$results[] = $found;
}
foreach ($array as $subarray)
$results = array_merge($results, $this->_search_array_by_value($subarray, $value));
}
return $results;
}
I hope it helps somebody :)
This is a revised function from the one that John K. posted... I need to grab only the specific key in the array and nothing above it.
function search_array ( $array, $key, $value )
{
$results = array();
if ( is_array($array) )
{
if ( $array[$key] == $value )
{
$results[] = $array;
} else {
foreach ($array as $subarray)
$results = array_merge( $results, $this->search_array($subarray, $key, $value) );
}
}
return $results;
}
$arr = array(0 => array(id=>1,name=>"cat 1"),
1 => array(id=>2,name=>"cat 2"),
2 => array(id=>3,name=>"cat 1"));
print_r(search_array($arr, 'name', 'cat 1'));
function findKey($tab, $key){
foreach($tab as $k => $value){
if($k==$key) return $value;
if(is_array($value)){
$find = findKey($value, $key);
if($find) return $find;
}
}
return null;
}
I think the easiest way is using php array functions if you know your key.
function search_array ( $array, $key, $value )
{
return array_search($value,array_column($array,$key));
}
this return an index that you could find your desired data by this like below:
$arr = array(0 => array('id' => 1, 'name' => "cat 1"),
1 => array('id' => 2, 'name' => "cat 2"),
2 => array('id' => 3, 'name' => "cat 1")
);
echo json_encode($arr[search_array($arr,'name','cat 2')]);
this output will:
{"id":2,"name":"cat 2"}
And another version that returns the key value from the array element in which the value is found (no recursion, optimized for speed):
// if the array is
$arr['apples'] = array('id' => 1);
$arr['oranges'] = array('id' => 2);
//then
print_r(search_array($arr, 'id', 2);
// returns Array ( [oranges] => Array ( [id] => 2 ) )
// instead of Array ( [0] => Array ( [id] => 2 ) )
// search array for specific key = value
function search_array($array, $key, $value) {
$return = array();
foreach ($array as $k=>$subarray){
if (isset($subarray[$key]) && $subarray[$key] == $value) {
$return[$k] = $subarray;
return $return;
}
}
}
Thanks to all who posted here.
If you want to search for array of keys this is good
function searchKeysInMultiDimensionalArray($array, $keys)
{
$results = array();
if (is_array($array)) {
$resultArray = array_intersect_key($array, array_flip($keys));
if (!empty($resultArray)) {
$results[] = $resultArray;
}
foreach ($array as $subarray) {
$results = array_merge($results, searchKeysInMultiDimensionalArray($subarray, $keys));
}
}
return $results;
}
Keys will not overwrite because each set of key => values will be in separate array in resulting array.
If you don't want duplicate keys then use this one
function searchKeysInMultiDimensionalArray($array, $keys)
{
$results = array();
if (is_array($array)) {
$resultArray = array_intersect_key($array, array_flip($keys));
if (!empty($resultArray)) {
foreach($resultArray as $key => $single) {
$results[$key] = $single;
}
}
foreach ($array as $subarray) {
$results = array_merge($results, searchKeysInMultiDimensionalArray($subarray, $keys));
}
}
return $results;
}
2 functions: array_search_key_value which returns the array of keys to reach a key with a value in a multidimensional array, array_extract_keys which returns the value in a multidimensional array pointed to by an array of keys.
function array_search_key_value($array, $key, $value) {
if (!is_array($array)) {
return false;
}
return array_search_key_value_aux($array, $key, $value);
}
function array_search_key_value_aux($array, $key, $value, $path=null) {
if (array_key_exists($key, $array) && $array[$key] === $value) {
$path[]=$key;
return $path;
}
foreach ($array as $k => $v ) {
if (is_array($v)) {
$path[]=$k;
$p = array_search_key_value_aux($v, $key, $value, $path);
if ($p !== false) {
return $p;
}
}
}
return false;
}
function array_extract_keys($array, $key_list) {
$v = $array;
foreach ($key_list as $key) {
if (!is_array($v) || !array_key_exists($key, $v))
return false;
$v = &$v[$key];
}
return $v;
}
Here is a unitary test:
$test_array = array(
'a' => array(
'aa' => true,
'ab' => array(
'aaa' => array(
'one' => 1,
'two' => 2,
'three' => 3,
'four' => 4
),
'four' => 4,
'five' => 5,
),
'six' => 6,
),
'seven' => 7
);
$test_data = array(
array('one', 1),
array('two', 2),
array('three', 3),
array('four', 4),
array('five', 5),
array('six', 6),
array('seven', 7),
array('zero', 0),
array('one', 0),
);
foreach ($test_data as $d) {
$r = array_search_key_value($test_array, $d[0], $d[1]);
echo $d[0] . ' => ' . $d[1] . ' ? ', $r ? implode('/', $r) . ' => ' . array_extract_keys($test_array, $r) : 'null', PHP_EOL;
}