swift属性分类、属性观察willSet-didSet

//
//  ViewController.swift
//  属性观察
//

import UIKit

class ViewController: UIViewController {

    // 一般属性，存储属性
    var Name: String = ""

    // 计算属性
    var totalName : String
    {
        return Name + "test"
    }

    // 带有观察者的属性
    var age : Int = 0
    {
        willSet
        {
            print("age will be \(newValue)")
        }
        didSet
        {
            print("\(oldValue) is set to be \(age)")
        }
    }

    override func viewDidLoad() {
        super.viewDidLoad()
        age = 10
        //   age will be 10
        //   0 is set to be 10
    }


}