multidimensional array dedupe

index.php

<?php


$array = [
  0 => [
    'id' => 'a'
  ],
  1 => [    
    'id' => 'b'
  ],
  2 => [
  'id' => 'a'
  ],
];


foreach ($array as $element) {
 $result[$element['id']] = $element;
}

$result = array_values($result);

var_export($result);