How to get month name with year and list of years

问题:

I want to get list of month names between two dates

Date1 : 1/1/2016

Date2 : 1/4/2017

Result should be : 
    January 2016 
    February 2016
    March 2016
    April 2016 To  April 2017

回答1:

Use below code to get a list of years between two dates.

func getYear(){
    let startDateString:String  = "05/21/2014"
    let endDateString:String = "05/21/2017"

    let dateFormtter = DateFormatter()
    dateFormtter.dateFormat = "MM/dd/yyyy"

    let startDate = dateFormtter.date(from: startDateString)
    let endDate = dateFormtter.date(from: endDateString)

    var arrYears = [String]()
    dateFormtter.dateFormat = "MM"

    if let startYear: Int = startDate?.year(), let endYear = endDate?.year() {
        for i in startYear...endYear {
            let monthWithYear = "\(i)"
            arrYears.append(monthWithYear)
        }
    }
}

extension Date {
   func Year() -> Int {
        let year = Calendar.current.component(.year, from: self)
        return year
    }
}

回答2:

 //let startDateString:String  = "01/01/2017"
 //let endDateString:String = "04/01/2017"

 let startDateString:String  = "08/01/2016"
 let endDateString:String = "04/01/2018"

 let dateFormtter = DateFormatter()
 dateFormtter.dateFormat = "MM/dd/yyyy"

 let startDate = dateFormtter.date(from: startDateString)
 let endDate = dateFormtter.date(from: endDateString)

 var monthsStringArray = [String]()
 var monthsIntArray = [Int]()
 var monthsWithyear = [String]()
 dateFormtter.dateFormat = "MM"

 if let startYear: Int = startDate?.year(), let endYear = endDate?.year() {

        if let startMonth: Int = startDate?.month(), let endMonth: Int = endDate?.month() {
            for i in startYear...endYear {
                for j in (i == startYear ? startMonth : 1)...(i < endYear ? 12 : endMonth) {
                    let monthTitle = dateFormtter.monthSymbols[j - 1]
                    monthsStringArray.append(monthTitle)
                    monthsIntArray.append(j)

                    let monthWithYear = "\(monthTitle) \(i)"
                    monthsWithyear.append(monthWithYear)
                }
            }
        }

 }

    print(monthsStringArray)
    print(monthsIntArray)
    print(monthsWithyear)


//-------
extension Date {

    func month() -> Int {
        let month = Calendar.current.component(.month, from: self)
        return month
    }

    func year() -> Int {
      let year = Calendar.current.component(.year, from: self)
      return year
   }
}

Result:
for dates between "01/01/2017" to "04/01/2017"
monthsStringArray = ["January", "February", "March", "April"]
monthsIntArray = [1, 2, 3, 4]
monthsWithyear = ["January 2017", "February 2017", "March 2017", "April 2017"]

for dates between "08/01/2016" to "04/01/2018"
monthsWithyear = ["August 2016", "September 2016", "October 2016", "November 2016", "December 2016", "January 2017", "February 2017", "March 2017", "April 2017", "May 2017", "June 2017", "July 2017", "August 2017", "September 2017", "October 2017", "November 2017", "December 2017", "January 2018", "February 2018", "March 2018", "April 2018"]

回答3:

    var monthsList = [String]()
    let fmt = DateFormatter()
    let startingMonthNumber:Int  = 0
    let endingMonthNumber:Int  = 3

    for i in startingMonthNumber..<endingMonthNumber {
        let monthName = fmt.monthSymbols[i]
        monthsList.append(monthName)
    }

    print(monthsList) //["January", "February", "March"]

回答4:

This is a solution with the method enumerateDates(startingAfter:matching:matchingPolicy:) of Calendarto enumerate dates very efficiently based on DateComponents

let calendar = Calendar.current
let dateFormtter = DateFormatter()
dateFormtter.dateFormat = "dd/MM/yyyy"

// create the start and end dates from the strings
let startDate = dateFormtter.date(from: "1/1/2016")!
let endDate = dateFormtter.date(from: "1/4/2017")!
// set the date format to the destination format
dateFormtter.dateFormat = "MMMM yyyy"

// Create the matching conponent : day 1 of each month
let components = DateComponents(day: 1)
// The variable result will contain the array of month names,
var result = [dateFormtter.string(from: startDate)]

// this particular method of Calendar enumerates each date matching the components
calendar.enumerateDates(startingAfter: startDate, matching: components, matchingPolicy: .nextTime) { (date, strict, stop) in
    result.append(dateFormtter.string(from: date!))
    // exit the enumeration if the end date is reached
    if date! >= endDate { stop = true }
}

print(result)

回答5:

Making the 'Krunal' answer a little more clean:

enum monthYearArrayType {
    case monthsStringArray
    case monthsIntArray
    case monthsWithyear
    case monthsWithyearExceptCurrent
}

func monthsBetweenDates(startDate: Date?, endDate: Date?, displayType: monthYearArrayType) -> Array<Any> {
    let dateFormtter = DateFormatter()

    var monthsStringArray = [String]()
    var monthsIntArray = [Int]()
    var monthsWithyear = [String]()
    var monthsWithyearExceptCurrent = [String]()
    dateFormtter.dateFormat = "MM"

    if let startYear: Int = startDate?.year(), let endYear = endDate?.year() {

        if let startMonth: Int = startDate?.month(), let endMonth: Int = endDate?.month() {
            for i in startYear...endYear {
                for j in (i == startYear ? startMonth : 1)...(i < endYear ? 12 : endMonth) {
                    let monthTitle = dateFormtter.monthSymbols[j - 1]
                    monthsStringArray.append(monthTitle)
                    monthsIntArray.append(j)

                    let monthWithYear = "\(monthTitle) \(i)"
                    monthsWithyear.append(monthWithYear)

                    if(i == Date().year()) {
                        monthsWithyearExceptCurrent.append(monthTitle)
                    } else {
                        monthsWithyearExceptCurrent.append(monthWithYear)
                    }
                }
            }
        }

    }

    switch displayType {
    case .monthsWithyear:
        return monthsWithyear
    case .monthsWithyearExceptCurrent:
        return monthsWithyearExceptCurrent
    case .monthsStringArray:
        return monthsStringArray
    case .monthsIntArray:
        return monthsIntArray
    }
}


extension Date {
    func month() -> Int {
        let month = Calendar.current.component(.month, from: self)
        return month
    }

    func year() -> Int {
        let year = Calendar.current.component(.year, from: self)
        return year
    }
}