Online PHP editor | output for 4ok0u

<?php $array1= [ [ "month1" => "January", "2020cs" => 84, "2020as" => 500, "2019cs" => 17, "2019as" => 500, ], [ "month1" => "February", "2020cs" => 54, "2020as" => 200, "2019cs" => 12, "2019as" => 1000, ], [ "month1" => "April", "2020cs" => 4, "2020as" => 100, "2019cs" => 12, "2019as" => 1400, ], [ "month1" => "November", "2020cs" => 0, "2020as" => 0, "2019cs" => 7, "2019as" => 200, ], ]; $array2= [ [ "month1" => "January", "2020cr" => 13, "2020ar" => 300, "2019cr" => 0, "2019ar" => 0, ], [ "month1" => "March", "2020cr" => 1, "2020ar" => 100, "2019cr" => 0, "2019ar" => 0, ], [ "month1" => "November", "2020cr" => 0, "2020ar" => 0, "2019cr" => 1, "2019ar" => 800, ], [ "month1" => "December", "2020cr" => 0, "2020ar" => 0, "2019cr" => 2, "2019ar" => 500, ], ]; // top-level array from indexed to associative (name of month) $array1 = rekey($array1); $array2 = rekey($array2); function rekey(array $arr = []): array { foreach ($arr as $key => $record) { $arr[$record['month1']] = $arr[$key]; // indexed to name of month unset($arr[$key]); } return $arr; } // run the merge $result = array_merge_recursive($array1, $array2); // clean up double entries key 'month1' foreach($result as $key => &$value) { if(is_array($value['month1'])) $value['month1'] = $value['month1'][0]; } // sort result set $months = ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December']; foreach($result as $key0 => $value0) { foreach($months as $key1 => $value1) { if($key0 === $value1) { $result[$key1] = $result[$key0]; // set index based on month 0-11 unset($result[$key0]); } } } ksort($result); print_r(array_values($result));