Can anyone tell me what's wrong with this variable?

[dontilydondon]

So i made a variable called $extension and when i use it in my code i keep getting this error: Undefined variable $extension and error 500.
heres the code:

$extension = strtolower(pathinfo($_FILES['image']['name'], PATHINFO_EXTENSION));
$errors['image_file'] .= in_array($extension, $file_extensions) ? '' : 'Wrong file extention ';

 

[VBService]

AFAIK, when $_FILES['image']['name'] not contain file name with extension (reason, e.g.: not fully uploaded file, etc.) then the function pathinfo return NULL.

Try use $_FILES['image']['type'] is more secure (browser check the type of file and set it up).

$errors['image_file'] = '';

$allowed_file_exts = ['image/jpeg', 'image/gif', 'image/png'];
$errors['image_file'] .= in_array($_FILES['image']['type'] ?? '', $allowed_file_exts) ? '' : 'Wrong file extention;';

[ null coalescing operator ?? in php ]