Only variables should be passed by reference

Question

// Other variables
$MAX_FILENAME_LENGTH = 260;
$file_name = $_FILES[$upload_name][\'name\'];
//echo \"testing-\".$file_name.\"
\";
//$file_name = strtolower         


        

Answer 1

Php 7 compatible proper usage:

$fileName      = 'long.file.name.jpg';
$tmp           = explode('.', $fileName);
$fileExtension = end($tmp);

echo $fileExtension;
// jpg