我们如何获得给定月份的星期日数量？ ( swift )

Question

我们如何获得给定月份的星期日数？平均他们是 4 但我们能得到指定月份星期日的确切数量吗？我不知道从哪里开始，所以任何关于计算星期日背后的逻辑或与此相关的任何事情的提示都会对我非常感激和帮助，

我正在尝试获取给定月份的总天数，并且我能够使用以下代码做到这一点：

func getNumberOfDaysInMonth (month : Int , Year : Int) -> Int{


    let dateComponents = NSDateComponents()
    dateComponents.year = Year
    dateComponents.month = month

    let calendar = NSCalendar.currentCalendar()
    let date = calendar.dateFromComponents(dateComponents)!

    // Swift 2:
    let range = calendar.rangeOfUnit(.Day, inUnit: .Month, forDate: date)

    let numDays = range.length

    return numDays


}

但我想从一个月中排除周日的数量

谢谢:)

Answer 1

func getNumberOfDaysInMonth (month : Int , Year : Int) -> Int{

    let dateComponents = NSDateComponents()
    dateComponents.year = Year
    dateComponents.month = month

    let calendar = NSCalendar.currentCalendar()
    let date = calendar.dateFromComponents(dateComponents)!

    let range = calendar.rangeOfUnit(.Day, inUnit: .Month, forDate: date)

    let numDays = range.length

    // New code starts here:

    var numberOfSundays = 0

    let dateFormatter = NSDateFormatter()

    for day in 1...numDays {

        dateComponents.day = day

        let date = calendar.dateFromComponents(dateComponents)!
        dateFormatter.dateFormat = "EEEE"
        let dayOfWeek = dateFormatter.stringFromDate(date) // Get day of week

        if dayOfWeek == "Sunday" { // Check if it's a Sunday
            numberOfSundays += 1
        }
    }

    return numDays - numberOfSundays
}

Answer 2

您可以使用第一天的星期几来计算星期日的数量并从计数中减去它：

    func getNumberOfDaysInMonth (month : Int , _ Year : Int) -> Int
{


    var dateComponents = DateComponents()
    dateComponents.year = Year
    dateComponents.month = month

    let calendar = Calendar.current
    let date = calendar.date(from: dateComponents)



    let range = calendar.range(of: .day, in: .month, for: date!)

    let numDays = range?.count

    let dow = calendar.component(.weekday, from: date!)
    let sundays = (numDays! + dow) / 7

    return numDays! - sundays


}

Answer 3

我在操场上创建了一个 class 到 return 一周中的任何几天作为结构。我想可以使用 enumerateDate。但是无论如何..还不确定守卫但是来了..

import UIKit

struct CalendarByWeekday {
    var Month = Int()
    var Year = Int()
    var Sundays = [Int]()
    var Mondays = [Int]()
    var Tuesdays = [Int]()
    var Wednesdays = [Int]()
    var Thursdays = [Int]()
    var Fridays = [Int]()
    var Saturdays = [Int]()

}
enum InvalidMonthInput: Error {
    case invalidInput
}


class Calculations {



class func calendar(month:Int ,year: Int) -> CalendarByWeekday {

//MARK: Prevent the input of invalid WeekDay.
    func protectMonth() throws -> Int {
   let monthRange = 1...12
    guard monthRange ~= month
        else {
           print("error")
            throw
            InvalidMonthInput.invalidInput
            //let nilStruct = CalendarByWeekday()
            //return nilStruct
        }
        return month
    }
    do {
        try!protectMonth()

    }

    var results = CalendarByWeekday()
    results.Month = month
    results.Year = year

    //MARK: Set the calendar.

    let calendar = Calendar(identifier: .gregorian)


    //MARK: Get the first day of the month.

    let components = DateComponents.init(calendar: calendar, year: year, month: month, day: 1)
    let firstDayOfTheMonth = calendar.date(from: components)
    let range = calendar.range(of: .day, in: .month, for: firstDayOfTheMonth!)

    //MARK: Get the first weekday of the month.

    let firstWeekdayOfTheMonth = calendar.component(.weekday, from: firstDayOfTheMonth!)

switch firstWeekdayOfTheMonth {
    case 1:
        if range!.count >= 29 {
            results.Sundays = [1,8,15,22,29]
        } else {
            results.Sundays = [1,8,15,22]
        }
        if range!.count >= 30 {
            results.Mondays = [2,9,16,23,30]
        } else {
            results.Mondays = [2,9,16,23]
        }
        if range!.count >= 31 {
            results.Tuesdays   = [3,10,17,24,31]
        } else {
            results.Tuesdays   = [3,10,17,24]
        }
        results.Wednesdays  = [4,11,18,25]
        results.Thursdays  = [5,12,19,26]
        results.Fridays   = [6,13,20,27]
        results.Saturdays  = [7,13,21,28]
    case 2:
        results.Sundays = [7,13,21,28]
        if range!.count >= 29 {
            results.Mondays = [1,8,15,22,29]
        } else {
            results.Mondays = [1,8,15,22]
        }
        if range!.count >= 30 {
            results.Tuesdays   = [2,9,16,23,30]
        } else {
            results.Tuesdays   = [2,9,16,23]
        }
        if range!.count >= 31 {
            results.Wednesdays  = [3,10,17,24,31]
        } else {
            results.Wednesdays  = [3,10,17,24]
        }
        results.Thursdays  = [4,11,18,25]
        results.Fridays   = [5,12,19,26]
        results.Saturdays  = [6,13,20,27]
    case 3:
        results.Sundays = [6,13,20,27]
        results.Mondays = [7,13,21,28]
        if range!.count >= 29 {
            results.Tuesdays   = [1,8,15,22,29]
        } else {
            results.Tuesdays   = [1,8,15,22]
        }
        if range!.count >= 30 {
            results.Wednesdays  = [2,9,16,23,30]
        } else {
            results.Wednesdays  = [2,9,16,23]
        }
        if range!.count >= 31 {
            results.Thursdays  = [3,10,17,24,31]
        } else {
            results.Thursdays  = [3,10,17,24]
        }
        results.Fridays   = [4,11,18,25]
        results.Saturdays  = [5,12,19,26]
    case 4:
        results.Sundays = [5,12,19,26]
        results.Mondays = [6,13,20,27]
        results.Tuesdays   = [7,13,21,28]
        if range!.count >= 29 {
            results.Wednesdays  = [1,8,15,22,29]
        } else {
            results.Wednesdays  = [1,8,15,22]
        }
        if range!.count >= 30 {
            results.Thursdays  = [2,9,16,23,30]
        } else {
            results.Thursdays  = [2,9,16,23]
        }
        if range!.count >= 31 {
            results.Fridays   = [3,10,17,24,31]
        } else {
            results.Fridays   = [3,10,17,24]
        }
        results.Saturdays  = [4,11,18,25]
    case 5:
        results.Sundays = [4,11,18,25]
        results.Mondays = [5,12,19,26]
        results.Tuesdays   = [6,13,20,27]
        results.Wednesdays  = [7,13,21,28]
        if range!.count >= 29 {
            results.Thursdays  = [1,8,15,22,29]
        } else {
            results.Thursdays  = [1,8,15,22]
        }
        if range!.count >= 30 {
            results.Fridays   = [2,9,16,23,30]
        } else {
            results.Fridays   = [2,9,16,23]
        }
        if range!.count >= 31 {
            results.Saturdays  = [3,10,17,24,31]
        } else {
            results.Saturdays  = [3,10,17,24]
        }
    case 6:
        if range!.count >= 31 {
            results.Sundays = [3,10,17,24,31]
        } else {
            results.Sundays = [3,10,17,24]
        }
        results.Mondays = [4,11,18,25]
        results.Tuesdays   = [5,12,19,26]
        results.Wednesdays  = [6,13,20,27]
        results.Thursdays  = [7,13,21,28]
        if range!.count >= 29 {
            results.Fridays   = [1,8,15,22,29]
        } else {
            results.Fridays   = [1,8,15,22]
        }

        if range!.count >= 30 {
            results.Saturdays  = [2,9,16,23,30]
        } else {
            results.Saturdays  = [2,9,16,23]
        }
    case 7:
        if range!.count >= 30 {
            results.Sundays = [2,9,16,23,30]
        } else {
            results.Sundays = [2,9,16,23]
        }
        if range!.count >= 31 {
            results.Mondays = [3,10,17,24,31]
        } else {
            results.Mondays = [3,10,17,24]
        }
        results.Tuesdays   = [4,11,18,25]
        results.Wednesdays  = [5,12,19,26]
        results.Thursdays  = [6,13,20,27]
        results.Fridays   = [7,13,21,28]
        results.Saturdays  = [1,8,15,22,29]
    default:
        print("error")
    }

    return results
}

}

let date = Date()
let myteste = Calculations.calendar(month: 2, year: 2018)

猜猜你可以创建一个常数，只排除星期日并使用它

我们如何获得给定月份的星期日数量？ ( swift )

how can we get the number of sundays on an given month ? ( swift )

logic

nsdate

swift