Swift中格式化日期

        Swift语言中格式化日期跟其它编程语言很相似：

        

var dformatter = NSDateFormatter()

dformatter.dateFormat = "yyyy年MM月dd日 HH:mm:ss"

var datestr = dformatter.stringFromDate(date)

 用Calendar操作日期 

let gregorian = NSCalendar(calendarIdentifier: NSCalendarIdentifierGregorian)

let now = NSDate()

var dateformatter = NSDateFormatter()
dateformatter.dateFormat = "yyyy-MM-dd"
let birthday = dateformatter.dateFromString("1986-11-10")

let components = gregorian?.components(NSCalendarUnit.CalendarUnitYear, fromDate: birthday!, toDate: now, options: NSCalendarOptions(0))

components?.year