基本类型 

    var a: Int64 = 12

    var b: String = ""

    var c: Float16 = 11.2

    var d: Bool = true

    var e: (Int16, String) = (3, "")

    var f: Array<(String, Bool)> = [("",false)]

    var g1 = 0..4     //0,1,2,3

    var g2 = 0..=4    //0,1,2,3,4

    var g3 = 0..4 : 2 //0,2

    var g4 = 4..0     //啥也没有

struct类型 

struct Goods{

    var name: String

    private var price: Int16

    var quantity: Int16 = 0 //初值可有可无，类型要有

    static var id: Int16 //静态元素必须要有

    static init() {

        id = 0

    }

    //init普通构造函数

    public init(name: String, price: Int16) {

        this.name = name

        this.price = price

    }

    //可以有多个构造函数，但参数列表不能一样

    // public init(name: String, price: Int16, quantity: Int16) {

    //     this.name = name

    //     this.price = price

    //     this.quantity = quantity

    // }

    //主构造函数

    public Goods(name: String, price: Int16, quantity: Int16){

        this.name = name

        this.price = price

        this.quantity = quantity

    }

    //静态函数，只操作静态元素

    static public func updateId(){

        id +=1

    }

    //成员函数

    public func totalPrice(): Int16{

        this.price*this.quantity

    }

    //mut允许修改元素，且不用于静态元素

    public mut func changeQuantuty(newQuentity: Int16){

        this.quantity = newQuentity

    }

   

}

Goods实例和函数调用

    var pen: Goods = Goods("pen", 3)

    Goods.updateId()

    pen.changeQuantuty(2)

    var pay = pen.totalPrice()