Online PHP editor | output for EdD63

<?php $classDays = ''; if($classDays[0] == '') { $classDaysD = 'Online'; } else { if (in_array(1, $classDays)) { $classDaysD = 'M'; } if (in_array(2,$classDays)) { $classDaysD .= ' T'; } if (in_array(3,$classDays)) { $classDaysD .= ' W'; } if (in_array(4,$classDays)) { $classDaysD .= ' Th'; } if (in_array(5,$classDays)) { $classDaysD .= ' F'; } if (in_array(6,$classDays)) { $classDaysD .= ' S'; } if (in_array(7,$classDays)) { $classDaysD .= ' Su'; } if ($classDaysD == '') { $classDaysD = 'M & W'; } } echo $classDaysD;