Php array unique subarray based on a value

Question

I am in a situation to make an array unique by the subarray index.Please refer this code and help me to solve this.

    $user=Array(
       [1]=>Array(
                 username => Sujith,
                 email=>someone@example.com,
                 [address] => Array(
                    [address_id] => 1227
                    [city] => Ayoor
                    [state] => Kerala
                    [Country] => India
                 )
      )
     [2]=>Array(
         username => Ajith,
         email=>someone2@example.com,
         [address] => Array(
            [address_id] => 1227
            [city] => Ayoor
            [state] => Kerala
            [Country] => India
        )
     )
     [3]=>Array(
         username => Akhil,
         email=>someone3@example.com,
         [address] => Array(
            [address_id] => 1228
            [city] => Kollam
            [state] => Kerala
            [Country] => India
        )

    )
 )

I want to make it unique by the address.address_id.So the resulting array should be

    $user=Array(
           [1]=>Array(
                     username => Sujith,
                     email=>someone@example.com,
                     [address] => Array(
                        [address_id] => 1227
                        [city] => Ayoor
                        [state] => Kerala
                        [Country] => India
                     )
          )
         [3]=>Array(
             username => Akhil,
             email=>someone3@example.com,
             [address] => Array(
                [address_id] => 1228
                [city] => Kollam
                [state] => Kerala
                [Country] => India
            )

        )
     )

I mean ,1 user per address..Please help me to solve this..

Sverri M. Olsen · Answer 1 · 2014-04-06T07:15:14.327

1

Loop through the $user array and unset() users, who's address_id has already occurred.

You can use an auxiliary array to keep track of address_ids that have occurred.

$addresses = array();
foreach ($user as $key => $value) {
    $id = $value['address']['address_id'];
    if (in_array($id, $addresses)) {
        unset($user[$key]);
    } else {
        $addresses[] = $id;
    }
}
unset($addresses);

edited Apr 06 '14 at 07:15

answered Mar 14 '14 at 07:41

Sverri M. Olsen

13,055
3
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Yes this is how it should work since there is no inbuilt function to do the operation. Using array_map and array_unique together we can get the unique address_id but this will require additional loop to generate the array as desired. Also with array_filter you need additional loop for generating the array. So yes in simple way your answer is pretty good !! – Abhik Chakraborty Mar 14 '14 at 09:11

pawle · Answer 2 · 2020-03-03T14:31:03.533

1

A short solution:

$ids = [];
$result = array_filter($user, function ($item) use (&$ids) {
    $id = $item['address']['address_id']; //or whatever you want to be unique
    if (in_array($id, $ids)) return false;

    $ids[] = $id;
    return true;
});

edited Mar 03 '20 at 14:31

answered Mar 03 '20 at 14:25

pawle

21
3

score 0 · Answer 3 · answered Mar 14 '14 at 07:40

0

$tmpArray = array();
$newArr = array();
foreach($users as $user)
{

if(!in_array($user['address']['address_id'],$tmpArray))
  $newArr[] = $user;
$tmpArray[] = $user['address']['address_id']
}
var_dump($newArr);

answered Mar 14 '14 at 07:40

MIIB

1,849
10
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score 0 · Answer 4 · answered Mar 14 '14 at 10:00

   $unique_array = array();
   $address_id_accumulator = array();
    foreach ($user as $k => $v) {         
        if ( !in_array( $v['address']['address_id'], $address_id_accumulator) ){
            $unique_array[$k] = $v;
        }
        $address_id_accumulator[] = $v['address']['address_id'];         
    }

Your $user array is the input here. $unique_array will be $user array with unique address id's.

score -2 · Answer 5 · answered Mar 14 '14 at 07:37

-2

There is no native PHP function doing explicitly what you want, but you could: - Do you own function, this takes 2 minutes - Use array_filter()

answered Mar 14 '14 at 07:37

Loenix

1,057
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Php array unique subarray based on a value

5 Answers5