结构体struct,类class

1.struct,值类型，结构体会自动生成初始化方法，class是引用类型

struct Person {
    var name : String
    var age : Int

    func simpleDescription() -> String {
        return "name = \(name) , age = \(age)"
    }
}

let p = Person(name: "ly", age: 9)
let k = p.simpleDescription()
print(k)