Get the first level key of the first row containing a specified column value in a 2d array

If you are using (PHP 5 >= 5.5.0) you don't have to write your own function to do this, just write this line and it's done.

If you want just one result:

$key = array_search(40489, array_column($userdb, 'uid')); 

For multiple results

$keys = array_keys(array_column($userdb, 'uid'), 40489); 

In case you have an associative array as pointed in the comments you could make it with:

single result :

$key = array_search(40489, array_combine(array_keys($userdb), array_column($userdb, 'uid'))) 

Multiple results :

$keys = array_keys(array_combine(array_keys($userdb), array_column($userdb, 'uid')),40489); 

If you are using PHP < 5.5.0, you can use this backport, thanks ramsey!

Update: I've been making some simple benchmarks and the multiple results form seems to be the fastest one, even faster than the Jakub custom function!

In later versions of PHP (>= 5.5.0) you can use this one-liner:

$key = array_search('100', array_column($userdb, 'uid')); 

Looks array_filter will be suitable solution for this...

$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' ) ); 

PHP Code

<?php $search = 5465; $found = array_filter($userdb,function($v,$k) use ($search){ return $v['uid'] == $search; },ARRAY_FILTER_USE_BOTH); // With latest PHP third parameter is optional.. Available Values:- ARRAY_FILTER_USE_BOTH OR ARRAY_FILTER_USE_KEY $values= print_r(array_values($found)); $keys = print_r(array_keys($found)); 

Building off Jakub's excellent answer, here is a more generalized search that will allow the key to specified (not just for uid):

function searcharray($value, $key, $array) { foreach ($array as $k => $val) { if ($val[$key] == $value) { return $k; } } return null; } 

Usage: $results = searcharray('searchvalue', searchkey, $array);

I know this was already answered, but I used this and extended it a little more in my code so that you didn't have search by only the uid. I just want to share it for anyone else who may need that functionality.

Here's my example and please bare in mind this is my first answer. I took out the param array because I only needed to search one specific array, but you could easily add it in. I wanted to essentially search by more than just the uid.

Also, in my situation there may be multiple keys to return as a result of searching by other fields that may not be unique.

 /** * @param array multidimensional * @param string value to search for, ie a specific field name like name_first * @param string associative key to find it in, ie field_name * * @return array keys. */ function search_revisions($dataArray, $search_value, $key_to_search) { // This function will search the revisions for a certain value // related to the associative key you are looking for. $keys = array(); foreach ($dataArray as $key => $cur_value) { if ($cur_value[$key_to_search] == $search_value) { $keys[] = $key; } } return $keys; } 

Later, I ended up writing this to allow me to search for another value and associative key. So my first example allows you to search for a value in any specific associative key, and return all the matches.

This second example shows you where a value ('Taylor') is found in a certain associative key (first_name) AND another value (true) is found in another associative key (employed), and returns all matches (Keys where people with first name 'Taylor' AND are employed).

/** * @param array multidimensional * @param string $search_value The value to search for, ie a specific 'Taylor' * @param string $key_to_search The associative key to find it in, ie first_name * @param string $other_matching_key The associative key to find in the matches for employed * @param string $other_matching_value The value to find in that matching associative key, ie true * * @return array keys, ie all the people with the first name 'Taylor' that are employed. */ function search_revisions($dataArray, $search_value, $key_to_search, $other_matching_value = null, $other_matching_key = null) { // This function will search the revisions for a certain value // related to the associative key you are looking for. $keys = array(); foreach ($dataArray as $key => $cur_value) { if ($cur_value[$key_to_search] == $search_value) { if (isset($other_matching_key) && isset($other_matching_value)) { if ($cur_value[$other_matching_key] == $other_matching_value) { $keys[] = $key; } } else { // I must keep in mind that some searches may have multiple // matches and others would not, so leave it open with no continues. $keys[] = $key; } } } return $keys; } 

Use of function

$data = array( array( 'cust_group' => 6, 'price' => 13.21, 'price_qty' => 5 ), array( 'cust_group' => 8, 'price' => 15.25, 'price_qty' => 4 ), array( 'cust_group' => 8, 'price' => 12.75, 'price_qty' => 10 ) ); $findKey = search_revisions($data,'8', 'cust_group', '10', 'price_qty'); print_r($findKey); 

Result

Array ( [0] => 2 ) 

You can do that with combination of two functions, array_search & array_column.

$search_value = '5465'; $search_key = 'uid'; $user = array_search($search_value, array_column($userdb, $search_key)); print_r($userdb[$user]); 

5465 is the user ID you want to search, uid is the key that contains user ID and $userdb is the array that is defined in the question.

References:

array_search on php.net

array_column on php.net

I modified one of examples below description function array_search. Function searchItemsByKey return all value(s) by $key from multidimensional array ( N levels). Perhaps , it would be useful for somebody. Example:

 $arr = array( 'XXX'=>array( 'YYY'=> array( 'AAA'=> array( 'keyN' =>'value1' ) ), 'ZZZ'=> array( 'BBB'=> array( 'keyN' => 'value2' ) ) //..... ) ); $result = searchItemsByKey($arr,'keyN'); print '<pre>'; print_r($result); print '<pre>'; // OUTPUT Array ( [0] => value1 [1] => value2 ) 

Function code:

function searchItemsByKey($array, $key) { $results = array(); if (is_array($array)) { if (isset($array[$key]) && key($array)==$key) $results[] = $array[$key]; foreach ($array as $sub_array) $results = array_merge($results, searchItemsByKey($sub_array, $key)); } return $results; } 

Here is one liner for the same,

$pic_square = $userdb[array_search($uid,array_column($userdb, 'uid'))]['pic_square']; 

Even though this is an old question and has an accepted answer, Thought i would suggest one change to the accepted answer.. So first off, i agree the accepted answer is correct here.

function searchArrayKeyVal($sKey, $id, $array) { foreach ($array as $key => $val) { if ($val[$sKey] == $id) { return $key; } } return false; } 

Replacing the preset 'uid' with a parameter in the function instead, so now calling the below code means you can use the one function across multiple array types. Small change, but one that makes the slight difference.

 // Array Data Of Users $userdb = array ( array ('uid' => '100','name' => 'Sandra Shush','url' => 'urlof100' ), array ('uid' => '5465','name' => 'Stefanie Mcmohn','url' => 'urlof100' ), array ('uid' => '40489','name' => 'Michael','url' => 'urlof40489' ), ); // Obtain The Key Of The Array $arrayKey = searchArrayKeyVal("uid", '100', $userdb); if ($arrayKey!==false) { echo "Search Result: ", $userdb[$arrayKey]['name']; } else { echo "Search Result can not be found"; } 

PHP Fiddle Example

I want to check tha in the following array $arr is there 'abc' exists in sub arrays or not

$arr = array( array( 'title' => 'abc' ) ); 

Then i can use this

$res = array_search('abc', array_column($arr, 'title')); if($res == ''){ echo 'exists'; } else { echo 'notExists'; } 

I think This is the Most simple way to define

No one else has used array_reduce yet, so thought I'd add this approach...

$find_by_uid = '100'; $is_in_array = array_reduce($userdb, function($carry, $user) use ($find_by_uid){ return $carry ? $carry : $user['uid'] === $find_by_uid; }); // Returns true 

Gives you more fine control over the 'search' logic than array_search().

Note that I have used strict equality here but you could opt for different comparison logic. The $carry means the comparison needs to be true once, and the final result will be TRUE.

I had to use un function which finds every elements in an array. So I modified the function done by Jakub Truneček as follow:

function search_in_array_r($needle, $array) { $found = array(); foreach ($array as $key => $val) { if ($val[1] == $needle) { array_push($found, $val[1]); } } if (count($found) != 0) return $found; else return null; } 

/** * searches a simple as well as multi dimension array * @param type $needle * @param type $haystack * @return boolean */ public static function in_array_multi($needle, $haystack){ $needle = trim($needle); if(!is_array($haystack)) return False; foreach($haystack as $key=>$value){ if(is_array($value)){ if(self::in_array_multi($needle, $value)) return True; else self::in_array_multi($needle, $value); } else if(trim($value) === trim($needle)){//visibility fix// error_log("$value === $needle setting visibility to 1 hidden"); return True; } } return False; } 

you can use this function ; https://github.com/serhatozles/ArrayAdvancedSearch

<?php include('ArraySearch.php'); $query = "a='Example World' and b>='2'"; $Array = array( 'a' => array('d' => '2'), array('a' => 'Example World','b' => '2'), array('c' => '3'), array('d' => '4'), ); $Result = ArraySearch($Array,$query,1); echo '<pre>'; print_r($Result); echo '</pre>'; // Output: // Array // ( // [0] => Array // ( // [a] => Example World // [b] => 2 // ) // // ) 

$a = ['x' => ['eee', 'ccc'], 'b' => ['zzz']]; $found = null; $search = 'eee'; array_walk($a, function ($k, $v) use ($search, &$found) { if (in_array($search, $k)) { $found = $v; } }); var_dump($found); 

Try this

<?php 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; } ?> 

I was looking for functionality similar to that of MySQL LIKE %term%. Based on the answers on this page. I am able to search the JSON array from a file.

user_list.json looks as sample below:

{ "user-23456": { "name": "John Doe", "age": "20", "email": "[email protected]", "user_id": "23456" }, "user-09876": { "name": "Ronojoy Adams", "age": "35", "email": "[email protected]", "user_id": "09876" }, "user-34890": { "name": "Will Artkin", "age": "16", "email": "[email protected]", "user_id": "34890" }, } /* *search_key_like */ function search_key_like($value, $key, $array) { $results=array(); $keyword = preg_quote($value, '~'); foreach ($array as $k => $val) { //if name a is spell John and keyword is sent as joh or JOH it will return null //to fix the issue convert the string into lowercase and uppercase $data=array($val[$key],strtolower($val[$key]),strtoupper($val[$key])); if (preg_grep('~' . $keyword . '~', $data)) { array_push($results,$val[$key]); } } return $results; } 

Usage===pulling the JSON file===

 $user_list_json='./user_list.json'; if(file_exists($user_list_json) && file_get_contents($user_list_json)){ $file_json_data=file_get_contents($user_list_json); $json_array_data=json_decode($file_json_data,true); $user_name_like = search_key_like('ron', 'name', $json_array_data); print "<pre>".print_r($user_name_like,true); } 

for( $i =0; $i < sizeof($allUsers); $i++) { $NEEDLE1='firstname'; $NEEDLE2='emailAddress'; $sterm='Tofind'; if(isset($allUsers[$i][$NEEDLE1]) && isset($allUsers[$i][$NEEDLE2]) { $Fname= $allUsers[$i][$NEEDLE1]; $Lname= $allUsers[$i][$NEEDLE2]; $pos1 = stripos($Fname, $sterm); $pos2=stripos($Lname, $sterm);//not case sensitive if($pos1 !== false ||$pos2 !== false) {$resultsMatched[] =$allUsers[$i];} else { continue;} } } Print_r($resultsMatched); //will give array for matched values even partially matched 

With help of above code one can find any(partially matched) data from any column in 2D array so user id can be found as required in question.

Expanding on the function @mayhem created, this example would be more of a "fuzzy" search in case you just want to match part (most) of a search string:

 function searchArrayKeyVal($sKey, $id, $array) { foreach ($array as $key => $val) { if (strpos(strtolower($val[$sKey]), strtolower(trim($id))) !== false) { return $key; } } return false; } 

For example the value in the array is Welcome to New York! and you wanted the first instance of just "New York!"

If question i.e.

$a = [ [ "_id" => "5a96933414d48831a41901f2", "discount_amount" => 3.29, "discount_id" => "5a92656a14d488570c2c44a2", ], [ "_id" => "5a9790fd14d48879cf16a9e8", "discount_amount" => 4.53, "discount_id" => "5a9265b914d488548513b122", ], [ "_id" => "5a98083614d488191304b6c3", "discount_amount" => 15.24, "discount_id" => "5a92806a14d48858ff5c2ec3", ], [ "_id" => "5a982a4914d48824721eafe3", "discount_amount" => 45.74, "discount_id" => "5a928ce414d488609e73b443", ], [ "_id" => "5a982a4914d48824721eafe55", "discount_amount" => 10.26, "discount_id" => "5a928ce414d488609e73b443", ], ]; 

Ans:

function searchForId($id, $array) { $did=0; $dia=0; foreach ($array as $key => $val) { if ($val['discount_id'] === $id) { $dia +=$val['discount_amount']; $did++; } } if($dia != '') { echo $dia; var_dump($did); } return null; }; print_r(searchForId('5a928ce414d488609e73b443',$a)); 

Just share, maybe can like this.

if( ! function_exists('arraySearchMulti')){ function arraySearchMulti($search,$key,$array,$returnKey=false) { foreach ($array as $k => $val) { if (isset($val[$key])) { if ((string)$val[$key] == (string)$search) { return ($returnKey ? $k : $val); } }else{ return (is_array($val) ? arraySearchMulti($search,$key,$val,$returnKey) : null); } } return null; }} 

Here is a better solution, in case your pulling data from a database or a multidimensional array

Example of a multidimensional array:

$records = array( array( 'id' => 2135, 'first_name' => 'John', 'last_name' => 'Doe', ), array( 'id' => 3245, 'first_name' => 'Sally', 'last_name' => 'Smith', ), array( 'id' => 5342, 'first_name' => 'Jane', 'last_name' => 'Jones', ), array( 'id' => 5623, 'first_name' => 'Peter', 'last_name' => 'Doe', ) ); function search_user_by_name($name, $array) { foreach ($array as $keys) { foreach ($keys as $key => $_user_record) { if ($_user_record == $name) { return [$key => $_user_record];//Return and array of user } } } return null; } 

Call the function:

$results = search_user_by_name('John', $records); print_r($results); 

Output: Array ( [first_name] => John )

From PHP8.4, there is a new, most-elegant, most-performant functional approach using array_find_key().

It functions like the "foreach() with a conditional early return" already mentioned on this page, but does so "under the hood" so that functional iterator performance is optimized.

array_filter(), array_column(), array_reduce(), array_map(), and array_walk(), etc. are all designed to fully traverse the input array regardless of if a match is found -- this makes them all less performant versus this new function (or ugly the short short circuit) when needing to return early.

Code: Demo

$uid = 100; var_export( array_find_key( $userdb, fn($row) => $row['uid'] == $uid ) ); 

If the only reason to return the first level key is so that the qualifying row can be later accessed, then skip the middle step and just return the qualifying row with array_find(). Demo

$uid = 100; var_export( array_find( $userdb, fn($row) => $row['uid'] == $uid ) ); 

Of course, if the search needle is the entire row, there is an older function that is well suited: array_search() (but returns false instead of null when there is no match). Demo

$row = [ 'uid' => '100', 'name' => 'Sandra Shush', 'pic_square' => 'urlof100' ]; var_export( array_search($row, $userdb) ); 

For Laravel users who are searching a collection (collect($userdb)), you can use the search() method. If no qualifying row is found, then the returned value will be false (like PHP's array_search()). PHPize Demo

$uid = 100; var_export( collect($userdb)->search(fn($row) => $row['uid'] == $uid) ); 

Note that Laravel's first(), firstOrFail(), and firstWhere() do not return the key of a qualifying value, they return the qualifying value.