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iOS

Chris Sehnert
Chris Sehnert
30,857 Points
Posted by Chris Sehnert
Chris Sehnert
30,857 Points

Strong Reference Cycles......the code is from a simple playground example that is supposed to demonstrate weak var usage

// the following example does not function the way the book describes.... // ...in my playground johnBoy continues to exist after he has been assigned nil..... /______________________________________________/

class NewerPerson { let name: String init(name: String) { self.name = name } var apartment: DifferentApartment? deinit { print("(name) is being deinitialized") } }

class DifferentApartment { let unit: String init(unit: String) { self.unit = unit } weak var tenant: NewerPerson? deinit { print("Apartment (unit) is being deinitialized") } }

var johnBoy: NewerPerson? var unit4C: DifferentApartment?

johnBoy = NewerPerson(name: "John-Boy") unit4C = DifferentApartment(unit: "4C")

johnBoy!.apartment = unit4C unit4C!.tenant = johnBoy

johnBoy = nil

var fourCTenant = unit4C!.tenant fourCTenant!.name var what = fourCTenant!.apartment

what!.unit var thatGuy = what!.tenant thatGuy!.name

print("as far as I can tell this weak reference is not working as advertised.....")

johnBoy thatGuy

/---------------------------------------------------/