ViewController.swift

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        let p = Person()
        
        print(p.title)
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }


}

import UIKit

class Person: NSObject {
    
    var _name: String?
//    var name: String? {
//        set {
//            _name = newValue
//        }
//        get {
//            return _name
//        }
//    }
    
    
    //只读属性  又叫做 计算性属性
    //一旦只实实现了 get方法 默认的隐含形式 添加的set方法 就会失效
    //并不会分配内存空间
    
    var name: String? {
        get {
            return "zhangsan"
        }
    }
    
    
    //并不需要分配内存空间
//    var title: String? {
//        get {
//            return "Boos" + (name ?? "")
//        }
//    }
    
    
    //简写方式
    var title: String? {
       
        return "Boos" + (name ?? "")
    }
    
    var model: NSObject? {
        didSet {
            //cell绑定数据
        }
    }
    
    
    
}