swift - 来自 8 位数据的一周中的几天

Question

从下面的 8 位中，我想了解哪些日子是活跃的。但我无法想出合适的解决方案。

0b00101101
   |     |
   |     Monday
   Sunday

我尝试的是:

func getWorkingDays(_ value: Data?) -> String? {
    guard let value = value else { return nil }
    if value.count == 1 {
        let days = calculateDays(value[0])
        return days
    }
    return nil
}

func calculateDays(_ days: UInt8?) -> String? {
        switch days {
        case 1:
            return "Monday"
        case 2:
            return "Tuesday"
        case 3:
            return "Monday, Tuesday"
        case 4:
            return "Wednesday"
        ......
}

Answer 1

您想了解如何使用 OptionSet。

You use the OptionSet protocol to represent bitset types, where individual bits represent members of a set.

在你的情况下，它看起来像这样。

struct Weekdays: OptionSet {
    let rawValue: Int

    static let monday    = Weekdays(rawValue: 1 << 0)
    static let tuesday   = Weekdays(rawValue: 1 << 1)
    static let wednesday = Weekdays(rawValue: 1 << 2)
    static let thrusday  = Weekdays(rawValue: 1 << 3)
    static let friday    = Weekdays(rawValue: 1 << 4)
    static let saturday  = Weekdays(rawValue: 1 << 5)
    static let sunday    = Weekdays(rawValue: 1 << 6)
}

然后将 Int 转换为 Weekdays

let data = 0b00101101
let weekdays = Weekdays(rawValue: data)

并检查它是否包含您的某一天或多天

if weekdays.contains(.monday) {
    print("It's monday!")
}