编辑代码

func shoushui(num:Double)->Double{
    var shui:Double = 0
    var chao:Double = 0
    switch num{
    case 0...5000:
        return shui
        break
    case 5001...10000:
        chao = num - 5000
        shui = chao * 0.03
        return shui
        break
    case 10001...20000:
        chao = num - 10000
        shui = chao * 0.1
        return shui
        break
    case 20001...30000:
        chao = num - 20000
        shui = chao * 0.2
        return shui
        break
    default:
        print("无法查询")
    }
    return shui
}
var ss = shoushui(num: 5555)
print("收税为：\(ss)")