//: Playground - noun: a place where people can play

import UIKit

class Person {
    var name : String = "" {
        // 屬性監(jiān)聽器: 選中其中之一即可
        // 監(jiān)聽屬性即將發(fā)生改變: 還沒有改變
        willSet(newName) {
            print(newName)
            print(name)
        }
        
        // 監(jiān)聽屬性已經(jīng)發(fā)生改變: 已經(jīng)改變
        didSet(oldName) {
            print(oldName)
            print(name)
        }
    }
}

let p = Person()

p.name = "why"
p.name = "lmj"