I'm trying to search through a multi-dimensional array to return the depth/value and whether it exists, but i'm having a little bit of trouble..
Theres a number of depths/dimensions of my array.. I'm storing current multi-dimensional arrays within others.. Here is an example:
array(
"UserInformation" => array(
array (
"Username" => "Test_User",
"Warnings" => 0,
"Post_ID" => array (7726,2254)
),
array (
"Username" => "Another",
"Warnings" => 2,
"WarningID" => array(8874,1125),
"Post_ID" => array (7726,2254)
),
),
"Mani" => 0,
"Aut" => 1,
"Wn" => 0,
"RTV"=> array(
"RunTime"=> "kk",
"Run_2" => "e",
"Perm"=>"p",
"DEp"=>"d")
);
Now, How would I go about searching the entire array index without nested for or foreach loops?
I've tried performing an array_search but this returns no aval as it only searches through the first dimension, and not in more depth?
You should try this one.
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))) {
return $current_key;
}
}
return false;
}
Here OR is for checking whether the needle value is same with the value you are searching. If it is true it will directly return the key and if it is not true it will first check the value is an array then call the same function recursively by changing its input with new nested array. So like this way it will iterate recursively end level of the array to find the value.
Amar's modified code which worked for me:
/*
* recusrive array search
* #param array $array
* #param string $needle
* #return string|int:
*/
public function recursiveFind(array $array, $needle)
{
$iterator = new RecursiveIteratorIterator(
new RecursiveArrayIterator($array),
RecursiveIteratorIterator::SELF_FIRST
);
foreach ($iterator as $key => $item) {
$current_key = $key;
if (is_array($item) && $key === $needle) {
return $current_key;
}
}
}
in this code case I needed ID (int) or keep looking in array (string) until I reach the one
Related
I have a deep multidimensional array that I am needing to extract the value of a specific key. I have found that the array_walk_recursive function will be my best option. I only need the first occurrence.
My array looks like this - (except much more complicated)
Array (
[vehicle info] => Array (
[one] => Array (
[submodel] => LX
[engine] => 2.3
)
[two] => Array (
[color] => blue
[year] => 2007
[wheels] => 4
)
[three] => Array (
[submodel] => LX
[make] => Ford
[model] => F-150
[offroad] => No
)
)
)
The issue here is, submodel is in both one and three. Additionally, the array is not consistent, so I must use array_walk_recursive to search through it for the matching key, then return the value for that key.
Here is my current code -
array_walk_recursive ($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, $arr));
}
// Output:
// string(14) "submodel is LX"
// string(12) "year is 2007"
Live demo
I have a string, I need to know at what index is that string exist in the array. My array is as follows:
array(3)
{
[0]=>object(stdClass)#47170 (3)
{
["countries"]=>string(2) "HK"
["last_seen_date"]=>string(10) "2016-09-17"
["ad_uid"]=>string(14) "157d5908a1ca83"
}
[1]=>object(stdClass)#47171 (3)
{
["countries"]=>string(2) "HK"
["last_seen_date"]=>string(10) "2016-09-27"
["ad_uid"]=>string(14) "157d7978513bc3"
}
[2]=>object(stdClass)#47230 (3)
{
["countries"]=>string(2) "HK"
["last_seen_date"]=>string(10) "2016-09-27"
["ad_uid"]=>string(14) "157ea7239824e9"
}
}
The last seen date is:2016-09-27.
I would like to know at what index does 2016-09-27 exist in the array. So I know what is ad_uid related to that date. I have a method which does this.
public function getAd_uid($last_seen_date,$values){
$key = array_keys($values,$last_seen_date);
print_r($key);
}
The result gets an empty array. I have tried array_serach() has same empty results. Any other alternative solutions to achieve results?
To find all $ad_uids last_seen at particular date you can use array_filter which will return you all elements you are looking for. If you need ad_uids only, you can apply array_map to that array as following:
<?php
// $array is the array in question.
$filtered = array_filter($array, function($item) {
return $item->last_seen_date == "2016-09-27";
});
$ad_uids = array_map(function($item){return $item->ad_uid;}, $filtered);
Example
As each each entry of your array is an object and you know the attributs' names of theses objects (I assume they never change), I would do it like this :
/**
* #param string $last_seen_date
* #param array $values
* #return mixed null|int
*/
function getAdUid($last_seen_date, array $values) {
// Just in case no entry match
$matching_index = null;
// Loop through each entry: $entry is an object
foreach($values as $index => $entry) {
if($entry->last_seen_date == $last_seen_date) {
$matching_index = $index;
break; // end loop: we found that we are looking for
}
}
return $matching_index;
}
to do that just loop your array
foreach($values as $key => $row) {
// do something
}
then check if $last_seen_date is equal to the loop index last_seen_date $row->last_seen_date
if ($row->last_seen_date == $last_seen_date) {
return $key;
}
if it is just return it
return $key;
so your php code would be like this
$arr = array(
0 =>
(object)array(
"countries" => "HK",
"last_seen_date" => "2016-09-17",
"ad_uid"=> "157d5908a1ca83"
),
1 =>
(object)array(
"countries" => "HK",
"last_seen_date" => "2016-09-20",
"ad_uid" => "157d7978513bc3"
),
2 =>
(object)array(
"countries" => "HK",
"last_seen_date" => "2016-09-26",
"ad_uid" => "157ea7239824e9"
)
);
function getAd_uid($last_seen_date, $values){
foreach($values as $key => $row) {
if ($row->last_seen_date == $last_seen_date) {
return $key;
}
}
}
echo '2016-09-17 is on index => '.getAd_uid('2016-09-17', $arr).'<br>';
echo '2016-09-20 is on index => '.getAd_uid('2016-09-20', $arr).'<br>';
echo '2016-09-26 is on index => '.getAd_uid('2016-09-26', $arr).'<br>';
RESULT
Working Demo
Below is dump of how my array looks like. There is inner array called officers and I would want to loop through it and check if there is officer of a specific name and if so I would want to get the index key of the outer array.
'edges' =>
array (size=59)
0 =>
array (size=3)
'source' => int 0
'target' => int 12
'officers' =>
array (size=1)
0 => string 'PARKER, Thomas, Sir' (length=19)
1 =>
array (size=3)
'source' => int 0
'target' => int 19
'officers' =>
array (size=1)
0 => string 'STEVENS, Anne' (length=13)
So if I checked for STEVENS, Anne I would want to get key 1.
Here is code I found in a different question it works with 2d arrays but not with 3d array.
function array_search_inner ($array, $attr, $val, $strict = FALSE) {
// Error is input array is not an array
if (!is_array($array)) return FALSE;
// Loop the array
foreach ($array as $key => $inner) {
// Error if inner item is not an array (you may want to remove this line)
if (!is_array($inner)) return FALSE;
// Skip entries where search key is not present
if (!isset($inner[$attr])) continue;
if ($strict) {
// Strict typing
if ($inner[$attr] === $val) return $key;
} else {
// Loose typing
if ($inner[$attr] == $val) return $key;
}
}
// We didn't find it
return NULL;
}
Since there can be several index keys that fit the condition, it is reasonable to implement the function as a generator:
function getOfficerIndexKey($data, $officerName) {
foreach ($data['edges'] as $key => $value) {
in_array($officerName, $value['officers']) && (yield $key);
}
}
Now you can iterate over all found values:
foreach (getOfficerIndexKey($data, 'STEVENS, Anne') as $indexKey) {
// Do something
}
As well as just get the first found one:
getOfficerIndexKey($data, 'STEVENS, Anne')->current();
How can i get the ['id'] from all children elements if i pass it an id.
This is my array...
$array = Array
(
'0' => Array
(
'id' => 1,
'parent_id' => 0,
'order_pos' => 0,
'title' => 'Shirts',
'childs' => Array
(
'0' => Array
(
'id' => 2,
'parent_id' => 1,
'order_pos' => 0,
'title' => 'Small Shirts',
)
)
),
'1' => Array
(
'id' => 3,
'parent_id' => 0,
'order_pos' => 0,
'title' => 'Cameras'
)
);
If i write i function and pass a variable of say id 1 can someone please tell me how i can return a single dimensional array with merely just the id's of all child elements.. For instance.
From the previous array, if i pass the id of 1, i want the function to return 1, 2 as 2 is an id element of a child element. So if i pass it 2, it should only return 2 as it doesnt have any children.
I hope you understand me, thank you if you can help me...
Note, this can be unlimited, meaning each parent category can have unlimited sub categories or children.
There is basically two problems you need to solve:
search the entire array for the given ID to start at.
pluck all the IDs from the children once the ID is found.
This would work:
function findIds(array $array, $id)
{
$ids = array();
$iterator = new RecursiveIteratorIterator(
new RecursiveArrayIterator($array),
RecursiveIteratorIterator::SELF_FIRST
);
foreach ($iterator as $val) {
if (is_array($val) && isset($val['id']) && $val['id'] === $id) {
$ids[] = $val['id'];
if (isset($val['childs'])) {
array_walk_recursive(
$val['childs'],
function($val, $key) use (&$ids) {
if ($key === 'id') {
$ids[] = $val;
}
}
);
}
}
}
return $ids;
}
print_r( findIds($array, 1) ); // [1, 2]
print_r( findIds($array, 2) ); // [2]
print_r( findIds($array, 3) ); // [3]
The Iterators will make your array fully traversable. This means, you can foreach over the entire array like it was a flat one. Normally, it would return only the leaves (1, 0, 0, Shirts, …), but since we gave it the SELF_FIRST option it will also return the arrays holding the leaves. Try putting a var_dump inside the foreach to see.
In other words, this
foreach ($iterator as $val) {
will go over each and every value in the array.
if (is_array($val) && isset($val['id']) && $val['id'] === $id) {
This line will only consider the arrays and check for the ID you passed to the findById function. If it exists, the ID is added to the array that will get returned by the function. So that will solve problem 1: finding where to start.
if (isset($val['childs'])) {
If the array has an item "childs" (it should be children btw), it will recursively fetch all the IDs from that item and add them to the returned array:
array_walk_recursive(
$val['childs'],
function($val, $key) use (&$ids) {
if ($key === 'id') {
$ids[] = $val;
}
}
);
The array_walk_recursive accepts an array (1st argument) and will pass the value and the key of the leaves to the callback function (2nd argument). The callback function merely checks if the leaf is an ID value and then add it to the return array. As you can see, we are using a reference to the return array. That is because using use ($ids) would create a copy of the array in the closure scope while we want the real array in order to add items to it. And that would solve problem 2: adding all the child IDs.
I need to search a multidimensional array for a specific value in any of the indexed subarrays.
In other words, I need to check a single column of the multidimensional array for a value. If the value exists anywhere in the multidimensional array, I would like to return true otherwise false
$my_array = array(
0 => array(
"name" => "john",
"id" => 4
),
1 => array(
"name" => "mark",
"id" => 152
),
2 => array(
"name" => "Eduard",
"id" => 152
)
);
I would like to know the fastest and most efficient way to check if the array $my_array contains a value with the key "id". For example, if id => 152 anywhere in the multidimensional array, I would like true.
Nothing will be faster than a simple loop. You can mix-and-match some array functions to do it, but they'll just be implemented as a loop too.
function whatever($array, $key, $val) {
foreach ($array as $item)
if (isset($item[$key]) && $item[$key] == $val)
return true;
return false;
}
The simplest way is this:
$my_array = array(
0 => array(
"name" => "john",
"id" => 4
),
1 => array(
"name" => "mark",
"id" => 152
),
2 => array(
"name" => "Eduard",
"id" => 152
)
);
if (array_search(152, array_column($my_array, 'id')) !== FALSE) {
echo 'FOUND!';
} else {
echo 'NOT FOUND!';
}
** PHP >= 5.5
simply u can use this
$key = array_search(40489, array_column($userdb, 'uid'));
Let's suppose this multi dimensional array:
$userdb=Array
(
(0) => Array
(
(uid) => '100',
(name) => 'Sandra Shush',
(url) => 'urlof100'
),
(1) => Array
(
(uid) => '5465',
(name) => 'Stefanie Mcmohn',
(pic_square) => 'urlof100'
),
(2) => Array
(
(uid) => '40489',
(name) => 'Michael',
(pic_square) => 'urlof40489'
)
);
$key = array_search(40489, array_column($userdb, 'uid'));
Here is an updated version of Dan Grossman's answer which will cater for multidimensional arrays (what I was after):
function find_key_value($array, $key, $val)
{
foreach ($array as $item)
{
if (is_array($item) && find_key_value($item, $key, $val)) return true;
if (isset($item[$key]) && $item[$key] == $val) return true;
}
return false;
}
If you have to make a lot of "id" lookups and it should be really fast you should use a second array containing all the "ids" as keys:
$lookup_array=array();
foreach($my_array as $arr){
$lookup_array[$arr['id']]=1;
}
Now you can check for an existing id very fast, for example:
echo (isset($lookup_array[152]))?'yes':'no';
A good solution can be one provided by #Elias Van Ootegan in a comment that is:
$ids = array_column($array, 'id', 'id');
echo isset($ids[40489])?"Exist":"Not Exist";
I tried it and worked for me, thanks buddy.
Edited
Note: It will work in PHP 5.5+
TMTOWTDI. Here are several solutions in order of complexity.
(Short primer on complexity follows):O(n) or "big o" means worst case scenario where n means the number of elements in the array, and o(n) or "little o" means best case scenario. Long discrete math story short, you only really have to worry about the worst case scenario, and make sure it's not n ^ 2 or n!. It's more a measure of change in computing time as n increases than it is overall computing time. Wikipedia has a good article about computational aka time complexity.
If experience has taught me anything, it's that spending too much time optimizing your programs' little-o is a distinct waste of time better spent doing something - anything - better.
Solution 0: O(n) / o(1) complexity:
This solution has a best case scenario of 1 comparison - 1 iteration thru the loop, but only provided the matching value is in position 0 of the array. The worst case scenario is it's not in the array, and thus has to iterate over every element of the array.
foreach ($my_array as $sub_array) {
if (#$sub_array['id'] === 152) {
return true;
}
}
return false;
Solution 1: O(n) / o(n) complexity:
This solution must loop thru the entire array no matter where the matching value is, so it's always going to be n iterations thru the array.
return 0 < count(
array_filter(
$my_array,
function ($a) {
return array_key_exists('id', $a) && $a['id'] == 152;
}
)
);
Solution 2: O(n log n) / o(n log n) complexity:
A hash insertion is where the log n comes from; n hash insertions = n * log n. There's a hash lookup at the end which is another log n but it's not included because that's just how discrete math works.
$existence_hash = [];
foreach ($my_array as $sub_array) {
$existence_hash[$sub_array['id']] = true;
}
return #$existence_hash['152'];
I came upon this post looking to do the same and came up with my own solution I wanted to offer for future visitors of this page (and to see if doing this way presents any problems I had not forseen).
If you want to get a simple true or false output and want to do this with one line of code without a function or a loop you could serialize the array and then use stripos to search for the value:
stripos(serialize($my_array),$needle)
It seems to work for me.
As in your question, which is actually a simple 2-D array wouldn't it be better? Have a look-
Let say your 2-D array name $my_array and value to find is $id
function idExists($needle='', $haystack=array()){
//now go through each internal array
foreach ($haystack as $item) {
if ($item['id']===$needle) {
return true;
}
}
return false;
}
and to call it:
idExists($id, $my_array);
As you can see, it actually only check if any internal index with key_name 'id' only, have your $value. Some other answers here might also result true if key_name 'name' also has $value
I don't know if this is better or worse for performance, but here is an alternative:
$keys = array_map(function($element){return $element['id'];}, $my_array);
$flipped_keys = array_flip($keys);
if(isset($flipped_keys[40489]))
{
// true
}
You can create a queue of sub-arrays and loop each:
function existsKeyValue($myArray, $key, $value) {
$queue = [$myArray]; //creating a queue of a single element, which is our outermost array
//when we reach the count of the queue we looped all inner loops as well and failed to find the item
for ($index = 0; $index < count($queue); $index++) {
//Looping the current array, finding the key and the value
foreach ($queue[$index] as $k => &$v) {
//If they match the search, then we can return true
if (($key === $k) && ($value === $v)) {
return true;
}
//We need to make sure we did not already loop our current array to avoid infinite cycles
if (is_array($v)) $queue[]=$v;
}
}
return false;
}
$my_array = array(
0 => array(
"name" => "john",
"id" => 4
),
1 => array(
"name" => "mark",
"id" => 152
),
2 => array(
"name" => "Eduard",
"id" => 152
)
);
echo var_dump(existsKeyValue($my_array, 'id', 152));
array_column returns the values of a single column of an array and we can search for a specific value for those via in_array
if (in_array(152, array_column($my_array, 'id'))) {
echo 'FOUND!';
} else {
echo 'NOT FOUND!';
}
Try with this below code. It should be working fine for any kind of multidimensional array search.
Here you can see LIVE DEMO EXAMPLE
function multi_array_search($search_for, $search_in) {
foreach ($search_in as $element) {
if ( ($element === $search_for) ){
return true;
}elseif(is_array($element)){
$result = multi_array_search($search_for, $element);
if($result == true)
return true;
}
}
return false;
}
You can use this with only two parameter
function whatever($array, $val) {
foreach ($array as $item)
if (isset($item) && in_array($val,$item))
return 1;
return 0;
}
different between isset vs array_key_exits
What's the difference between isset() and array_key_exists()?
different between == vs === How do the PHP equality (== double equals) and identity (=== triple equals) comparison operators differ?
function specificValue(array $array,$key,$val) {
foreach ($array as $item)
if (array_key_exits($item[$key]) && $item[$key] === $val)
return true;
return false;
}
function checkMultiArrayValue($array) {
global $test;
foreach ($array as $key => $item) {
if(!empty($item) && is_array($item)) {
checkMultiArrayValue($item);
}else {
if($item)
$test[$key] = $item;
}
}
return $test;
}
$multiArray = array(
0 => array(
"country" => "",
"price" => 4,
"discount-price" => 0,
),);
$test = checkMultiArrayValue($multiArray);
echo "<pre>"
print_r($test);
Will return array who have index and value
I wrote the following function in order to determine if an multidimensional array partially contains a certain value.
function findKeyValue ($array, $needle, $value, $found = false){
foreach ($array as $key => $item){
// Navigate through the array completely.
if (is_array($item)){
$found = $this->findKeyValue($item, $needle, $value, $found);
}
// If the item is a node, verify if the value of the node contains
// the given search parameter. E.G.: 'value' <=> 'This contains the value'
if ( ! empty($key) && $key == $needle && strpos($item, $value) !== false){
return true;
}
}
return $found;
}
Call the function like this:
$this->findKeyValue($array, $key, $value);