Online PHP editor | refs for BhpAG

<?php $array = array( "date_2019_12" => 0, "date_2019_11" => 0, "date_2019_10" => 0, "date_2019_09" => 0, "date_2019_08" => 0, "date_2019_07" => 0, "date_2019_06" => 0, "date_2019_05" => 0, "date_2019_04" => 0, "date_2019_03" => 0, "date_2019_02" => 0, "date_2019_01" => 10, "date_2018_12" => 1, "date_2018_11" => 2, "date_2018_10" => 3, "date_2018_09" => 4, "date_2018_08" => 5, "date_2018_07" => 6, ); $year = 2019; $sums = array(); for ($i = 1; $i <= 12; $i++) { $sum = 0; for ($j = $i - 5; $j <= $i; $j++) { $y = $year; $m = $j; if ($m <= 0) { $m += 12; $y -= 1; } $date = sprintf("date_%4d_%02d", $y, $m); $sum += $array[$date]; } $date = sprintf("date_%4d_%02d", $year, $i); $sums[$date] = $sum; } print_r($sums);