Online PHP editor | refs for kUa8D

<?php $array = [['range' => 336, 'year' => 2020],['range' => 336, 'year' => 2020],['range' => 390, 'year' => 2020],['range' => 390, 'year' => 2021]]; $idList = array_flip(array_values(array_unique(array_column($array, 'range')))); $newDatesCurrent = []; foreach($array as $value) { $newDatesCurrent[] = ['range' => $idList[$value['range']], 'year' => $value['year'], 'month' => 222]; } print_r($newDatesCurrent);