Swift 数组，字典，结构体，枚举

1.数组

let types = ["none","warning","error"]//省略类型的数组声明
        var menbers = [String]()//声明空数组
        menbers.append("six")//添加元素
        menbers += ["seven"]//添加元素
        menbers.insert("one", at: 0)//指定位置添加元素
        menbers[0] = "message"//通过下标修改元素
        menbers[0...2] = ["message","banana","orange"]//通过区间修改元素
        print(types)
        print(menbers)
        print(menbers.count)//数组个数
        print(menbers.isEmpty)//数组是否为空
        menbers.swapAt(1, 2)//元素之间交换
        //menbers.remove(at: 2)//删除某一个元素
        //menbers.removeLast()//删除最后一个元素
        let addStringArr = types + menbers
        //数组遍历
        for value in addStringArr {
            print("\(value)")
        }
        //元祖遍历
        for (index,value) in menbers.enumerated() {
            print("索引:\(index) 数据:\(value)")
        }
        
        //过滤数组元素
        let newTypes = types.filter { (item) -> Bool in
            return item.count < 6
        }
        print(newTypes)
        
        //创建包含100个元素的数组
        let items = Array(0..<100).map{ "条目\($0)"}
        print(items)

 

//2.0 字典
        //var emptyDict = [String : Int]()//空字典
        //声明一个字典
        var myDict = ["name":"hangge","url":"hangge.com"]
        myDict["address"] = "china" //添加/修改字典
        myDict.removeValue(forKey: "name")//删除某一个key
        myDict["name"] = nil //删除某一个key值
        //字典的key,value
        print(myDict.keys,myDict.values)
        //遍历字典
        for (key,value) in myDict {
            print("\(key):\(value)")
        }
        //顾虑字典元素
        let dict2 = myDict.filter { (item) -> Bool in
            return item.value.count < 7
        }
        print(dict2)
        
        //通过元祖创建字典
        let duplicatesArray = [("Monday",30),("Tuesday",25),("Wednesday",27),("Sunday",29)]
        let dic = Dictionary(duplicatesArray, uniquingKeysWith: min)
        print(dic)
        
        //合并字典
        var dict1 = ["one":10,"two":20]
        //merge 合并
        let tuples = [("one",5),("three",30)]
        dict1.merge(tuples, uniquingKeysWith: min)
        print("dict:\(dict1)")
        //merging 合并
        let dict3 = dict1.merging(tuples, uniquingKeysWith: min)
        print("dict2:\(dict3)")
        
        //字典不存在时,指定默认值
        let dict4 = ["apple":1,"banana":2]
        var orange : Int
        if let value = dict4["orange"] {
            orange = value
        }else {
            orange = 0
        }
        let longan = dict4["longan",default:0]
        
        print(orange)
        print(longan)

//创建一个结构体
        struct BookInfo {
            var id : Int = 0
            var name : String = "default"
            var authord : String = "default"
        }
        var book1 : BookInfo //默认构造器创建结构体
        var book2 : BookInfo = BookInfo.init(id: 0021, name: "航哥", authord: "hanggge")
        book1 = book2
        book2.id = 1234
        print(book1,book2)
        
        //枚举
        enum Compasspoint {
            case north
            case south
            case east
            case west
        }
        let directionTohead = Compasspoint.east
        print(directionTohead)
        
        enum Planet : Int {
            case mercury = 1
            case venus = 2
            case earth = 3
        }
        let earthsorder = Planet.earth
        print(earthsorder)
        
        enum Direction {
            case up
            case down
            func description() -> String {
                switch self {
                case .up:
                    return "向上"
                case .down:
                    return "向下"
                }
            }
        }
        print(Direction.up.description())

 

//默认构造器
class Student{
    var name : String = ""
    var number : Int = 0
}
//自定义构造函数
class Person{
    //雷属性
    var name:String
    var age:Int
    //类构造函数
    init(newName:String,newAge:Int) {
        self.name = newName
        self.age = newAge
    }
    //实例函数
    func say() -> String {
        return "我叫MT\(name)"
    }
}
class People {
    //普通属性
    var firstName:String = ""
    var lastName:String = ""
    var nickName:String = ""
    
    //计算属性
    var fullName:String {
        get {
            return nickName + " " + firstName + " " + lastName
        }
    }
    //带属性监视器普通属性
    var age:Int = 0 {
        //属性变化前
        willSet{
            print("will set an new value\(age) to age")
        }
        didSet{
            print("age file change form \(oldValue) to \(age)")
            if age < 10 {
                nickName = "Little"
            }else{
                nickName = "Big"
            }
        }
    }
    func toString() ->String{
        return "Full name \(fullName) +_ age\(age)"
    }
}
/*结构体运用*/
struct Account {
    var amount:Double = 0.0
    var owner:String = ""
    //修饰静态方法
    static var interestRate:Double = 0.668
    static func interestBy(amount:Double) ->Double{
        return interestRate * amount
    }
}
class Account_class {
    var amount:Double = 0.0
    var owner:String = ""
    
    class var staticProp: Double {
        return 0.668
    }
    class func interestBy(amount:Double) ->Double{
        return staticProp * amount
    }
}