Online PHP editor | output for iGG8S

<?php class Student { private $classes; public function __construct($classes) { $this->classes = $classes; } public function getClasses() { return $this->classes; } public function combineClasses(Student $otherStudent) { $allClasses = array_unique(array_merge($this->classes, $otherStudent->classes)); $this->classes = $allClasses; $otherStudent->classes = $allClasses; } } $mary = new Student(['CompSci2001', 'CompSci2002']); $john = new Student(['CompSci2002', 'CompSci2003']); $mary->combineClasses($john); var_dump($mary->getClasses()); var_dump($john->getClasses());