How to loop through table columns in PHP?

Question

PHP

Task: loop through all columns. This code works great as long as it $last_columncontains one character.

$last_column = 'AM';
for ($column = 'A'; $column <= $last_column; $column++) {
  echo "$column ";
}

But if in $last_column2 characters, instead of:

ABC ... XYZ AA AB AC ...AK AL AM

Outputs only:

A

It can be done through the column iterator in PHPExcel, but it's more convenient for me to get the column name in the form of letters.

Answer 1

$last_column = 'AM';
$column_number = 0;
do {
    $column_name = (($t = floor($column_number / 26)) == 0 ? '' : chr(ord('A')+$t-1)).
                    chr(ord('A')+floor($column_number % 26));
    echo "{$column_name} ";
    $column_number++;
} while ($column_name != $last_column);

Answer 2

Surely the author is not relevant), but for history, let it be ...

$last_column = 'AM';
for ($column = 'A'; $column != $last_column; $column++) {
    echo "$column ";
}
//или 
$column = 'A';
$last_column = 'AM';
while ($column != $last_column) {
    echo $column.' ';
    $column++;
}

//а в частном случае обычно я использую так
//$columnNamesArr массив с именами столбцов
$column_name = 'A';
foreach ($columnNamesArr as $columnName) {
    $objPHPExcel->getActiveSheet()->SetCellValue($column_name.'1', $columName);
    $objPHPExcel->getActiveSheet()->getColumnDimension($column_name)->setAutoSize(true);
    $column_name++;
}