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<?php $arr1 = [ ['gross_value' => '100', 'quantity' => '1'], ['gross_value' => '200', 'quantity' => '1'] ]; $arr2 = [ ['item_title_id' => '1', 'order_id' => '4'], ['item_title_id' => '2', 'order_id' => '4'] ]; foreach ($arr1 as $i => &$row) { $row = array_merge($row, $arr2[$i]); } var_export($arr1);
Output for 7.4.0 - 7.4.33, 8.0.1 - 8.0.30, 8.1.0 - 8.1.34, 8.2.0 - 8.2.30, 8.3.0 - 8.3.30, 8.4.1 - 8.4.22, 8.5.0 - 8.5.7
array ( 0 => array ( 'gross_value' => '100', 'quantity' => '1', 'item_title_id' => '1', 'order_id' => '4', ), 1 => array ( 'gross_value' => '200', 'quantity' => '1', 'item_title_id' => '2', 'order_id' => '4', ), )

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67.83 ms | 1306 KiB | 4 Q