Swift Switch String Return

Question

您好我有一个简单的switch case语句，它有一个错误＆＃34;在预期返回的函数中缺少返回＆＃39; String＆＃39;＆＃34;

我所能看到的就是我要归还一切。没有if语句，因此它不能成为缺失的回报。

enum Sign { case rock, paper, scissors }

func detectWinner(player: Sign, bot: Sign) -> String{
    switch player{
    case .rock:
        switch(bot){
        case .rock: return "You Tied"
        case .paper: return "You Lost"
        case .scissors: return "You Won"
        }
    case .paper:
        switch(bot){
            case .rock: return "You Won"
            case .paper: return "You Tied"
            case .scissors: return "You Lost"
        }
    case .scissors:
        switch(bot){
            case .rock: return "You Lost"
            case .paper: return "You Won"
            case .scissors: return "You Tied"
        }
    }
}

Answer 1

正如其他人所说，你的代码应该编译，因为你彻底处理了所有的switch语句。尝试清洁和重建。

顺便说一下，这似乎很好地使用了带有元组的switch语句：

enum Sign { case rock, paper, scissors }

func detectWinner(player: Sign, bot: Sign) -> String{
    switch (player, bot){
    case (.rock, .rock): return "You Tied"
    case (.rock, .paper): return "You Lost"
    case (.rock, .scissors): return "You Won"

    case (.paper, .rock): return "You Won"
    case (.paper, .paper): return "You Tied"
    case (.paper, .scissors): return "You Lost"

    case (.scissors, .rock): return "You Lost"
    case (.scissors, .paper): return "You Won"
    case (.scissors, .scissors): return "You Tied"
    }
}

这比嵌套的switch语句更容易阅读和维护。 （它为我建造，至少在游乐场中建造）

Answer 2

Xcode很奇怪。程序关闭修复了这个奇怪的错误。