PHP remove array of associative array that have a duplicate values of specific key

Question

I\'ve a array of associative array

array(xxx) {
 [0]=>
   array(3) {
    [\"group_id\"]=>2
    [\"contact\"]=> \"foo\"
    [\"contact_email\"]=> \"fo         


        

Answer 1

You can use foreach and group them by contact_email

$r = [];
foreach($a as $v){
 $r[$v['contact_email']] = $v;
}
print_r(array_values($r));// reorder index

Working example : https://3v4l.org/0oN8h

Answer 2

Extract to an array and index by contact_email. Since there cannot be duplicate indexes you'll get the last occurrence:

$array = array_column($array, null, 'contact_email');

If you want to re-index that back to integers:

$array = array_values(array_column($array, null, 'contact_email'));

Answer 3

I think this can help

$arr = [['contact_email' => 'a@a.com'], ['contact_email' => 'a@a.com'], ['contact_email' => 'b@a.com']];
$result = [];
array_map(function ($item) use (&$result) {
    $result[$item['contact_email']] = $item;
}, $arr);
print_r($result);