Online PHP editor | refs for 0oN8h

<?php $a = [ [ 'group_id' => 2, 'contact' => 'foo', 'contact_email' => 'foo@gmail.com' ], [ 'group_id' => 2, 'contact' => 'bar', 'contact_email' => 'bar@gmail.com' ], [ 'group_id' => 2, 'contact' => 'foobar', 'contact_email' => 'bar@gmail.com' ], [ 'group_id' => 2, 'contact' => 'bar', 'contact_email' => 'bar@gmail.com' ] ]; $r = []; foreach($a as $v){ $r[$v['contact_email']] = $v; } print_r(array_values($r));