swift 4.0 类 结构体 属性

类 结构体

//结构体
struct teacher {
    var name:String = ""
    var age:Int = 19
    
}


class Student{
    var name:String = ""
    var age:Int = 18
}

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        let classItem = Student() //创建实例
        classItem.name = "花花菇凉"
        print(classItem.name)
    }
}

属性

import UIKit


class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        var allName = newClass()
        allName.name
        
        let stepCount = StepCount()
        stepCount.examplePro = 200
    }
    
    
}


class Student {
    var name:String?
    var age:Int = 10
}


class newClass{
//    lazy var name = "小明"    //懒加载属性
    
    var lastName = "小小"
    var firstName = "苏"
    
    var name:String{
        get {
            return firstName + lastName
        }
    }
}


class StepCount {
    var examplePro:Int = 10 {
        willSet (newTotal){
            //在属性更改之前做的操作
            print("新值是\(newTotal)")
        }
        
        didSet{
            //在属性更改之后的操作
            print("新值-旧值\(examplePro - oldValue)")
        }
    }
}