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<?php $a[] = ["name" => "aaaaa", "projectId" => 0, "area" => "AreaX"]; $a[] = ["name" => "bbbbb", "projectId" => 2, "area" => ""]; $b[] = ["name" => "cccc", "projectId" => 1, "area" => ""]; $b[] = ["name" => "aaaaa", "projectId" => 0, "area" => "AreaX"]; $col = "projectId"; $res = array_diff(array_column($a, $col), array_column($b, $col)); print_r(array_map(function($id) use ($col) {return [$col => $id];}, $res));
Output for 7.1.25 - 7.1.31, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.33, 8.2.0 - 8.2.29, 8.3.0 - 8.3.27, 8.4.1 - 8.4.14
Array ( [1] => Array ( [projectId] => 2 ) )

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