swift 结构体和枚举

结构体

1. 创建一个结构体

struct BookInfo{
    
    var ID:Int = 0
    var Name:String = "defaut"
    var Author:String = "defaut"
    
}

2 构造结构体

var book2 = BookInfo(ID: 002, Name: "小时代", Author: "郭敬明") //调用逐一构造器创建结构体
book2.ID = 003 //修改内部值

枚举

1. 创建

enum CompassPoint {
    
    case north
    case south
    case east
    case west
}
var dicect = CompassPoint.east

2. rawValue

enum Planet: Int {
    
    case mercury = 1
    case venus = 2
    case earth = 3
    
}

let earthOrder = Planet.earth.rawValue // rawValue来获取他的原始值:3
let venusPlanet = Planet(rawValue: 2) // //通过原始值来寻找所对应的枚举成员:Venus

3. swith

enum Direction {
    
    case up
    case down
    
    func desription1() ->String
    {
        switch self {
        case .up:
            
            return "在上面"
        case .down:
            return "在下面"
            
        default:
            
            return "nothing"
    }
        
    }

}


print(Direction.up.desription1())