更好的方式来获得ios swift上的一天的名字

Question

我把这一天的名字命名为

func loadDayName(forDate date: NSDate) -> String{
    let myComponents = calendar.components(.Weekday, fromDate: date)
    let weekDay = myComponents.weekday
    switch weekDay {
    case 1:
        return "Sunday"
    case 2:
        return "Monday"
    case 3:
        return "Tuesday"
    case 4:
        return "Wednesday"
    case 5:
        return "Thursday"
    case 6:
        return "Friday"
    case 7:
        return "Saturday"
    default:
        return "Nada"
    }
}

它是工作查找,但我想知道swift是否自带一些库自动比我在手动代码中做得更好

Answer 1

使用 DateFormatter

斯威夫特4

let date = Date()
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "EEEE"
let dayInWeek = dateFormatter.string(from: date)

Swift3

let date = NSDate()
let dateFormatter = NSDateFormatter()
dateFormatter.dateFormat  = "EEEE" // "EE" to get short style
let dayInWeek = dateFormatter.stringFromDate(date) // "Sunday"    

截图

Answer 2

如果要获取日期名称数组，可以使用： weekdaySymbols in Calendar()

例：

let calendar = Calendar(identifier: .gregorian)
let days = calendar.weekdaySymbols

Answer 3

自 iOS 15 以来有一个新的 api。

@available(macOS 12.0, iOS 15.0, tvOS 15.0, watchOS 8.0, *)
extension FormatStyle where Self == Date.FormatStyle {

    public static var dateTime: Date.FormatStyle { get }
}

您现在可以使用：

Date().formatted(.dateTime.month(.wide)) // October
Date().formatted(.dateTime.year(.defaultDigits)) // 2022
Date().formatted(.dateTime.weekday(.wide)) // Thursday
Date().formatted(.dateTime.weekday(.abbreviated)) // Thu
Date().formatted(.dateTime.weekday(.narrow)) // T

等等等等