用map 、flatMap 、 filter、 reduce 及扩展等强行打造自己的小作坊

某天你跟后台发生矛盾了，直接给你返回一串字符串...(⊙o⊙)?

let scoreStr = "小东:87;小龙:81;小天:97;小六:76;小张:54;小熙:94;小西:20;小伍:76;小迪:64;小马:36"

extension String {
    /*
     * 切割字符串->数组
     */
    func split(str: String) -> [String] {
        return self.componentsSeparatedByString(str)
    }
}

//总分 A作坊  整理 -> 过滤车间 -> 打包车间
let t1 = scoreStr.split(";")
                  .flatMap{ Double($0.split(":")[1]) }
                  .reduce(0, combine: +) // = 685

//总分 B作坊  整理 -> 多功能车间
let t2 = scoreStr.split(";")
                 .reduce(0) { (r, c) -> Double in
                       return r + Double(c.split(":")[1])!
                    } // = 685
//取及格分数的人
let p = scoreStr.split(";").filter {
                    Double($0.split(":")[1])! > 60
               }
print(p) // = ["小东:87", "小龙:81", "小天:97", "小六:76", "小熙:94", "小伍:76", "小迪:64"]

//取小天的分数
let xiaoTian = scoreStr.split(";")
                    .reduce(0){ (r,c) -> Double in
                    if c.hasPrefix("小天") {
                        return Double(c.split(":")[1])!
                    }
                      return r
                    }

//那么一个个取也不是办法，要取其他人的咋办，好办，交给小作坊
extension String {
    /*
     *专为该字符串服务的临时小作坊
     * 输入名字 —> 分数
    */
    func find(str:String) -> Double {
       let rs = self.split(";")
                    .reduce(0){ (r,c) -> Double in
                        if c.hasPrefix(str) {
                        return Double(c.split(":")[1])!
                       }
               return r
          }
        return rs
    }
}

scoreStr.find("小龙") // = 81

//平均分
let average = totalScore/Double(scoreStr.split(";").count) // = 68.5

///#变成数组
let strArr = scoreStr.split(";")
print(strArr) // = ["小东:87", "小龙:81", "小天:97", "小六:76", "小张:54", "小熙:94", "小西:20", "小伍:76", "小迪:64", "小马:36"]

///#变成字典
//#简单循环模式
var dict = [String:Int]()
scoreStr.split(";").forEach {
                 let k = $0.split(":")[0]
                 let v = $0.split(":")[1]
                    dict[k] = Int(v)
                }
print(dict) // = ["小六": 76, "小天": 97, "小龙": 81, "小伍": 76, "小东": 87, "小马": 36, "小熙": 94, "小西": 20, "小迪": 64, "小张": 54]

/*
let dict2 = scoreStr.split(";")
    .map { (c) -> [String:Int] in
        let k = c.split(":")[0]
        let v = c.split(":")[1]
        return [k:Int(v)!]} */

///#字典变回字符串
let rStr = dict.reduce("") { (r,c) -> String in
            var r = r
            r += (c.0 + ":" + String(c.1) + ";")
           return r
           }
print(rStr) // = 小六:76;小天:97;小龙:81;小伍:76;小东:87;小马:36;小熙:94;小西:20;小迪:64;小张:54;

/*
let rStr = dict.reduce("") { (r, c) in
    return r + (c.0 + ":" + String(c.1) + ";")
}
*/