Hello all,

I am working on allowing user to select country from a list. I can get list of all countries from iOS with Locale.isoRegionCodes and then getting localized name for users locale with localizedString(forRegionCode:. I also have the sorting based on current Locale working pretty great.

But I got kind of stuck on creating groups by first letter and showing those in Table View. I cannot come up with something elegant..

let groups = Dictionary(grouping: countries) { (country) -> Character in
            return country.first!
}

This will create groups based on country's first letter but it is not something that can be readily shown in Table View because I need to access those groups based on section index..

Thanks for help!

Couple of different semi-elegant ways I would consider. One would be to simply create a separate instance variable to hold your section mapping from indexes to letters:

let sectionIndexes = groups.keys.sorted() // Array<Character>: ["A", "B", "C"...]

Then you can get your section count by sectionIndexes.count, and when asked for the countries in a section i, call groups[sectionIndexes[i]]!.

Or, you could combine it all in to one array that holds tuples of your section letters and countries:

let sections = Dictionary(grouping: countries) { (country) -> Character in
        return country.first!
    }
    .map { (key: Character, value: [String]) -> (letter: Character, countries: [String]) in
        (letter: key, countries: value)
    }
    .sorted { (left, right) -> Bool in
        left.letter < right.letter
    }
// [(letter: "A", countries: ["Afghanistan", "Albania", ...]), (letter: "B", countries: ["Bahamas", "Bahrain", ...])]

Section count would be sections.count, and you can get the letter and countries of each section i by sections[i].letter and sections[i].countries.

(You could also map to CountrySection structs with similar properties if tuples aren't your bag.)