Question

我正在开发一个Swift应用程序。它有一个格式为dd-mm-yyyy的字符串日期数组。同一日期可以多次出现。当我点击一个按钮时，我想获得所有数据，这些数据的月份等于当前日期的最后2个月。

例如：数组包含一些元素，如01-10-2013，23-11-2013，20-12-2013，20-12-2013，20-12-2013和当前日期{{1} }。当我单击一个按钮时，包含月份20-12-2013的所有数据都应保存在另一个数组中。

我该怎么做？

Answer 1

使用NSCalendar，NSDateFormatter，NSDate和NSDateComponents：

import Foundation

let cal = NSCalendar.currentCalendar()
let formatter = NSDateFormatter()
formatter.locale = NSLocale(localeIdentifier: "en_US_POSIX")
formatter.dateFormat = "dd-MM-yyyy"

let now = NSDate()
let target = cal.dateByAddingUnit(.CalendarUnitMonth, value: -2, toDate: now, options: nil)!
let targetcomps = cal.components(.CalendarUnitYear | .CalendarUnitMonth , fromDate: target)

let ary = ["01-10-2014", "23-11-2014", "20-12-2014", "20-12-2014", "20-10-2014"]
let result = ary.filter {
    if let date = formatter.dateFromString($0) {
        return targetcomps == cal.components(.CalendarUnitYear | .CalendarUnitMonth , fromDate: date)
    }
    return false
}

println(result)

Answer 2

尝试以下swift数组过滤器，

       let array = ["01-10-2013", "23-11-2013", "20-12-2013", "20-12-2013", "20-12-2013"];
        var iIndex = 0
        let filteredArray = array.filter { 
            let myDate = $0 as NSString
            let currentMonth = 12 // get it dynamically
            let currentDate = 20 // get it dynamically
            let currentYear = 2014

            let monthToCompare = currentMonth - 2

            if(
               myDate.substringWithRange(NSRange(location: 0, length: 2)) == ("" + currentDate) 
            && myDate.substringWithRange(NSRange(location: 3, length: 2)) == ("" + monthToCompare)
            && myDate..substringWithRange(NSRange(location: 6, length: 4)) == ("" + currentYear)
        ){

                println("Original Index"+\(iIndex))
                return true
            }else{
                return false
            }

            iIndex++
        }

        println(filteredArray) // This should have filtered array

如何从包含日期字符串的数组中获取数据

2 个答案: