Retain Cycle

RetainCycle.swift

class Person {
    let name: String
    var pet: Pet?

    init(name: String) {
        self.name = name
        print("\(name) is being initialized.")
    }

    deinit {
        print("\(name) is being deinitialized.")
    }
}

class Pet {
    let name: String
    var owner: Person?

    init(name: String) {
        self.name = name
        print("\(name) is being initialized.")
    }

    deinit {
        print("\(name) is being deinitialized.")
    }
}

// Creating a retain cycle
var john: Person? = Person(name: "John")
var cat: Pet? = Pet(name: "Whiskers")

// Assigning references to create a retain cycle
john?.pet = cat
cat?.owner = john

// Setting the references to nil to break the retain cycle
john = nil
cat = nil