How to find the nearest date of the stored data

Question

For example:

• stored data: date = data1(2015.12.31), data2(2016.01.05), data3(2016.01.14), data4(2016.01.15), data5(2016.01.18)
• today is 2016.01.12
• then nearest data is data3

What are the methods that can be called here data3?

realDate(datePicker.date), date(textField.text), content(textField.text) in Core Data.

var stores: Contact!
// Contact is CoreData Entity Name.
@IBOutlet weak var label: UILabel!

ViewController viewDidLoad :

let list = [stores]
let timeSort = list.map{_ in stores?.realDate!.timeIntervalSinceNow}.filter{$0 > 0}.sort(<)
  if let firstTime = timeSort.first {
  _ = NSDate(timeIntervalSinceReferenceDate: firstTime!)
    if timeSort.first != nil {
      label.text = stores?.content
    } else { }
  }

I was trying to get help for writing code. There is no error, it does not display any information on the label.

Answer 1

You can use NSDate property timeIntervalSinceNow to sort your dates and get the first positive value:

edit/update:

Swift 3 introduced Date which conforms to Comparable protocol so it can be easily sorted now:

extension Date {
    init?(_ year: Int,_ month: Int,_ day: Int) {
        guard let date = DateComponents(calendar: .current, year: year, month: month, day: day, hour: 12).date else { return nil }
        self = date
    }
}

Playground testing:

let dateList = [Date(2018, 2, 18)!, Date(2017, 12, 31)!, Date(2018, 1, 5)!, Date(2018, 2, 14)!, Date(2018, 2, 15)!]

if let closestDate = dateList.sorted().first(where: {$0.timeIntervalSinceNow > 0}) { // "Feb 15, 2018, 12:00 PM"
    print(closestDate.description(with: .current)) // Thursday, February 15, 2018 at 12:00:00 PM Brasilia Summer Time
}