Im trying to fetch values from cells in my xlsx file. Im using the `getCellbyColumnAndRow()->getValue()` function inside my 2 loops.

```
$file = 'test.xlsx';
try {
    $inputFileType = PHPExcel_IOFactory::identify($file);
    $objReader = PHPExcel_IOFactory::createReader($inputFileType);
    $objPHPExcel = $objReader->load($file);
    $sheet = $objPHPExcel->getActiveSheet();
} catch(Exception $e) {
    die('Error loading file "'.pathinfo($inputFileName,PATHINFO_BASENAME).'": '.$e->getMessage());
}

// get worksheet dimentions
$higestRow = $sheet->getHighestDataRow();
$highestCol = $sheet->getHighestDataColumn();

//get value from all the cells
for($i = 1; $i <= $higestRow; $i++){
    for($j = 'A'; $j <= $highestCol; $i++){ 
        echo $sheet->getCellByColumnAndRow($j, $i)->getValue();
        echo "</br>";
    }
}

```

But it seems to get stuck in an infinit loop. Why?

Also, when I do `getCellByColumnAndRow('I', 16);` I get the value in cell `A16`. But when I do `getCellByColumnAndRow(8,16)`. I get the value from `I16`. So this also means that rows index starts with 1 and column index starts with 1.