我有從txt文件中提取數組的代碼，它正在刪除我不需要的列并將其插入到csv文件中。我正在使用的代碼是刪除列，但我希望它檢查兩列，如果一個為空，則將其刪除并使用下一列。它不是根據列 12 是否為空而循環每行，它基本上只是對第一行運行一次 if 語句并將其應用于每一行。while ($data = fgetcsv($f_in, 8000, "|")) {    $columns = [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36]; //index of columns    if (empty($columns['12'])) {        $unwanted = [1,2,3,4,5,6,7,8,9,10,11,12,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36]; //index of unwanted columns        foreach($unwanted as $i) {            unset($data[$i]);        }    } else {        $unwanted = [1,2,3,4,5,6,7,8,9,10,11,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36]; //index of unwanted columns        foreach($unwanted as $i) {            unset($data[$i]);        }    }    fputcsv($f_out, $data, ',', '"');我得到相同的結果，而不是為每行循環。    if ($columns['12'] > 0) 謝謝