连接自定义对象数组

Question

我创建了一个自定义对象，其中包含 id、名称和短名称。我只想检索 id 并执行 a 操作，",".join()使其成为一个字符串，例如"1, 2"

那么如何将数组转换var recentArray = Array<News>()为仅 id 以逗号分隔的字符串呢？

定制类

class Team: NSObject{
    var id: Int!
    var name: NSString!
    var shortname: NSString!


    init(id: Int, name:NSString, shortname: NSString) {
        self.id = id
        self.name = name
        self.shortname = shortname
    }


    required convenience init(coder aDecoder: NSCoder) {
        let id = aDecoder.decodeIntegerForKey("id")
        let name = aDecoder.decodeObjectForKey("name") as! String
        let shortname = aDecoder.decodeObjectForKey("shortname") as! String
        self.init(id: id, name: name, shortname: shortname)
    }

    func encodeWithCoder(aCoder: NSCoder) {
        aCoder.encodeInteger(id, forKey: "id")
        aCoder.encodeObject(name, forKey: "name")
        aCoder.encodeObject(shortname, forKey: "shortname")
    }    
}

Answer 1

你有你使用的map功能。

var t1 = Team(id: 1, name: "Adria", shortname: "Ad")
var t2 = Team(id: 2, name: "Roger", shortname: "Ro")
var t3 = Team(id: 3, name: "Raquel", shortname: "Ra")

var array: [Team] = [t1, t2, t3];

var arrayMap: Array = array.map(){ toString($0.id) }
var joinedString: String  = ",".join(arrayMap)

println(joinedString) // 1,2,3