Odtnhj

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:

$keys = array_keys(array_combine(array_keys($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!

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 ) 

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;

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;
) 

$values= print_r(array_value($found)); 
$keys = print_r(array_keys($found)); 

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

Here is one liner for the same,

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

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);

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

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;

Try this also

function search_in_array($srchvalue, $array)

 if (is_array($array) && count($array) > 0)
 
 $foundkey = array_search($srchvalue, $array);
 if ($foundkey === FALSE)
 
 foreach ($array as $key => $value)
 
 if (is_array($value) && count($value) > 0)
 
 $foundkey = search_in_array($srchvalue, $value);
 if ($foundkey != FALSE)
 return $foundkey;
 
 
 
 else
 return $foundkey;
 

for( $i =0; $i < sizeof($allUsers); $i++)
 
 $NEEDLE1='firstname';
 $NEEDLE2='emailAddress';
 $sterm='Tofind';
 if(isset($allUsers[$i][$NEEDLE1]) && isset($allUsers[$i][$NEEDLE2])
 


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!"

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;
 
 ?>

$search1 = 'demo';
$search2 = 'bob';
$arr = array('0' => 'hello','1' => 'test','2' => 'john','3' => array('0' => 'martin', '1' => 'bob'),'4' => 'demo');
foreach ($arr as $value) 
 if (is_array($value)) 
 if (in_array($search2, $value)) 
 echo "successsfully"; 
 //execute your code 
 
 else 
 if ($value == $search1) 
 echo "success";
 
 
 

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));