// 1.創(chuàng)建類
class Student {
var book : Book?
deinit {
print("Student -- deinit")
}
}
class Book {
var owner : Student?
deinit {
print("Book -- deinit")
}
}
// 2.創(chuàng)建對象
var stu : Student? = Student()
var book: Book? = Book()
// 3.相互引用
stu?.book = book!
book?.owner = stu
// 4.對象置nil
stu = nil
book = nil
