Александр Тихонов

let greeting = "Guten Tag!"
greeting[greeting.startIndex]
// G
greeting[greeting.endIndex.predecessor()]
// !
greeting[greeting.startIndex.successor()]
// u
let index = greeting.startIndex.advancedBy(7)
greeting[index]
// a

var str = "Hello, playground"
for chr in str.characters.reverse() {
    print(chr)
}

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
        
        ...
        let userDefaults = NSUserDefaults.standardUserDefaults()
        if var numberOfLaunches = userDefaults.objectForKey("numberOfLaunches") as? Int {
            numberOfLaunches++
            userDefaults.setInteger(numberOfLaunches, forKey: "numberOfLaunches")
        } else {
            let n = 1
            userDefaults.setInteger(n, forKey: "numberOfLaunches")
        }
        print(userDefaults.objectForKey("numberOfLaunches") as! Int)
        
        return true
    }

override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
        selectedIndexPath = tableView.indexPathForSelectedRow
        tableView.beginUpdates()
        tableView.endUpdates()
    }
    
    override func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
        if selectedIndexPath == indexPath {
            return 107
        } else {
            return 50
        }
    }

for element in array { 
if element < min {...}
...
}

• NSDateFormatter для установки формата даты
  
• NSDateComponents для операций со сложением/вычитанием единиц времени (дни, месяцы, годы и т.д.)
  
• NSCalendar для того чтобы указать тип календаря ( currentCalendar(), Григорианский или какой-то еще)
  

let dateFormatter = NSDateFormatter()
dateFormatter.timeStyle = NSDateFormatterStyle.NoStyle
let gmtTimeZone = NSTimeZone(abbreviation: "GMT")
dateFormatter.timeZone = gmtTimeZone
dateFormatter.dateFormat = "yyyyMMdd"

var dates = [String]()

let threeMonthAgoComponent = NSDateComponents()
threeMonthAgoComponent.month = -3

var date = NSDate()
let calendar = NSCalendar.currentCalendar()
let lastDate = calendar.dateByAddingComponents(threeMonthAgoComponent, toDate: date, options: NSCalendarOptions(rawValue: 0))

let dayAgoComponent = NSDateComponents()
dayAgoComponent.day = -1

while (date != lastDate) {
    date = calendar.dateByAddingComponents(dayAgoComponent, toDate: date, options: NSCalendarOptions.MatchFirst)!
    dates.append(dateFormatter.stringFromDate(date))
}

print(dates)

override func tableView(tableView: UITableView, willDisplayCell cell: UITableViewCell, forRowAtIndexPath indexPath: NSIndexPath) {
        let lastRow = indexPath.row
        if lastRow == objects.count - 1 {
            fetchData(lastRow)
        }
    }
    
    private func fetchData(lastRow: Int) {
        dispatch_after(dispatch_time(DISPATCH_TIME_NOW, 1 * Int64(NSEC_PER_SEC)), dispatch_get_main_queue()) { () -> Void in
        let object = "New data"
        self.objects.append(object)
        self.tableView.insertRowsAtIndexPaths([NSIndexPath(forRow: lastRow + 1, inSection: 0)], withRowAnimation: .Automatic)
        }
    }