When should I use deinit?

Question

I came across a function called deinit() while reading The Swift Programming Language guide, but I'm still wondering why and when we need to implement it since we don't really need to manage memory.

Answer 1

It's not required that you implement that method, but you can use it if you need to do some action or cleanup before deallocating the object.

The Apple docs include an example:

struct Bank {     static var coinsInBank = 10_000     static func vendCoins(var numberOfCoinsToVend: Int) -> Int {         numberOfCoinsToVend = min(numberOfCoinsToVend, coinsInBank)         coinsInBank -= numberOfCoinsToVend         return numberOfCoinsToVend     }     static func receiveCoins(coins: Int) {         coinsInBank += coins     } }  class Player {     var coinsInPurse: Int     init(coins: Int) {         coinsInPurse = Bank.vendCoins(coins)     }     func winCoins(coins: Int) {         coinsInPurse += Bank.vendCoins(coins)     }     deinit {         Bank.receiveCoins(coinsInPurse)     } } 

So whenever the player is removed from the game, its coins are returned to the bank.