Swift turn a country code into a emoji flag via unicode

Here's a general formula for turning a two-letter country code into its emoji flag:

func flag(country:String) -> String {
    let base = 127397
    var usv = String.UnicodeScalarView()
    for i in country.utf16 {
        usv.append(UnicodeScalar(base + Int(i)))
    }
    return String(usv)
}

let s = flag("DE")

EDIT Ooops, no need to pass through the nested String.UnicodeScalarView struct. It turns out that String has an append method for precisely this purpose. So:

func flag(country:String) -> String { 
    let base : UInt32 = 127397
    var s = ""
    for v in country.unicodeScalars {
        s.append(UnicodeScalar(base + v.value))
    }
    return s
}

EDIT Oooops again, in Swift 3 they took away the ability to append a UnicodeScalar to a String, and they made the UnicodeScalar initializer failable (Xcode 8 seed 6), so now it looks like this:

func flag(country:String) -> String {
    let base : UInt32 = 127397
    var s = ""
    for v in country.unicodeScalars {
        s.unicodeScalars.append(UnicodeScalar(base + v.value)!)
    }
    return String(s)
}

If anyone looking for solution in ObjectiveC here is convenient category:

@interface NSLocale (RREmoji)

+ (NSString *)emojiFlagForISOCountryCode:(NSString *)countryCode;

@end


@implementation NSLocale (RREmoji)


+ (NSString *)emojiFlagForISOCountryCode:(NSString *)countryCode {
    NSAssert(countryCode.length == 2, @"Expecting ISO country code");

    int base = 127462 -65;

    wchar_t bytes[2] = {
        base +[countryCode characterAtIndex:0],
        base +[countryCode characterAtIndex:1]
    };

    return [[NSString alloc] initWithBytes:bytes
                                    length:countryCode.length *sizeof(wchar_t)
                                  encoding:NSUTF32LittleEndianStringEncoding];
}


@end

test:

for ( NSString *countryCode in [NSLocale ISOCountryCodes] ) {
    NSLog(@"%@ - %@", [NSLocale emojiFlagForISOCountryCode:countryCode], countryCode);
}

output: 🇦🇩 - AD 🇦🇪 - AE 🇦🇫 - AF 🇦🇬 - AG 🇦🇮 - AI ...

Two optimizations of matt's answer.

No need to pass through the nested String in Swift 4
To avoid pass lower case string, I added uppercased()

Here is the code.

func flag(from country:String) -> String {
    let base : UInt32 = 127397
    var s = ""
    for v in country.uppercased().unicodeScalars {
        s.unicodeScalars.append(UnicodeScalar(base + v.value)!)
    }
    return s
}

I know this is not exactly what was asked, but maybe it will help someone:

let flags: [String: String] = [
  "AD": "🇦🇩", "AE": "🇦🇪", "AF": "🇦🇫", "AG": "🇦🇬", "AI": "🇦🇮", "AL": "🇦🇱", "AM": "🇦🇲", "AO": "🇦🇴", "AQ": "🇦🇶", "AR": "🇦🇷", "AS": "🇦🇸", "AT": "🇦🇹", "AU": "🇦🇺", "AW": "🇦🇼", "AX": "🇦🇽", "AZ": "🇦🇿", "BA": "🇧🇦", "BB": "🇧🇧", "BD": "🇧🇩", "BE": "🇧🇪", "BF": "🇧🇫", "BG": "🇧🇬", "BH": "🇧🇭", "BI": "🇧🇮", "BJ": "🇧🇯", "BL": "🇧🇱", "BM": "🇧🇲", "BN": "🇧🇳", "BO": "🇧🇴", "BQ": "🇧🇶", "BR": "🇧🇷", "BS": "🇧🇸", "BT": "🇧🇹", "BV": "🇧🇻", "BW": "🇧🇼", "BY": "🇧🇾", "BZ": "🇧🇿", "CA": "🇨🇦", "CC": "🇨🇨", "CD": "🇨🇩", "CF": "🇨🇫", "CG": "🇨🇬", "CH": "🇨🇭", "CI": "🇨🇮", "CK": "🇨🇰", "CL": "🇨🇱", "CM": "🇨🇲", "CN": "🇨🇳", "CO": "🇨🇴", "CR": "🇨🇷", "CU": "🇨🇺", "CV": "🇨🇻", "CW": "🇨🇼", "CX": "🇨🇽", "CY": "🇨🇾", "CZ": "🇨🇿", "DE": "🇩🇪", "DJ": "🇩🇯", "DK": "🇩🇰", "DM": "🇩🇲", "DO": "🇩🇴", "DZ": "🇩🇿", "EC": "🇪🇨", "EE": "🇪🇪", "EG": "🇪🇬", "EH": "🇪🇭", "ER": "🇪🇷", "ES": "🇪🇸", "ET": "🇪🇹", "FI": "🇫🇮", "FJ": "🇫🇯", "FK": "🇫🇰", "FM": "🇫🇲", "FO": "🇫🇴", "FR": "🇫🇷", "GA": "🇬🇦", "GB": "🇬🇧", "GD": "🇬🇩", "GE": "🇬🇪", "GF": "🇬🇫", "GG": "🇬🇬", "GH": "🇬🇭", "GI": "🇬🇮", "GL": "🇬🇱", "GM": "🇬🇲", "GN": "🇬🇳", "GP": "🇬🇵", "GQ": "🇬🇶", "GR": "🇬🇷", "GS": "🇬🇸", "GT": "🇬🇹", "GU": "🇬🇺", "GW": "🇬🇼", "GY": "🇬🇾", "HK": "🇭🇰", "HM": "🇭🇲", "HN": "🇭🇳", "HR": "🇭🇷", "HT": "🇭🇹", "HU": "🇭🇺", "ID": "🇮🇩", "IE": "🇮🇪", "IL": "🇮🇱", "IM": "🇮🇲", "IN": "🇮🇳", "IO": "🇮🇴", "IQ": "🇮🇶", "IR": "🇮🇷", "IS": "🇮🇸", "IT": "🇮🇹", "JE": "🇯🇪", "JM": "🇯🇲", "JO": "🇯🇴", "JP": "🇯🇵", "KE": "🇰🇪", "KG": "🇰🇬", "KH": "🇰🇭", "KI": "🇰🇮", "KM": "🇰🇲", "KN": "🇰🇳", "KP": "🇰🇵", "KR": "🇰🇷", "KW": "🇰🇼", "KY": "🇰🇾", "KZ": "🇰🇿", "LA": "🇱🇦", "LB": "🇱🇧", "LC": "🇱🇨", "LI": "🇱🇮", "LK": "🇱🇰", "LR": "🇱🇷", "LS": "🇱🇸", "LT": "🇱🇹", "LU": "🇱🇺", "LV": "🇱🇻", "LY": "🇱🇾", "MA": "🇲🇦", "MC": "🇲🇨", "MD": "🇲🇩", "ME": "🇲🇪", "MF": "🇲🇫", "MG": "🇲🇬", "MH": "🇲🇭", "MK": "🇲🇰", "ML": "🇲🇱", "MM": "🇲🇲", "MN": "🇲🇳", "MO": "🇲🇴", "MP": "🇲🇵", "MQ": "🇲🇶", "MR": "🇲🇷", "MS": "🇲🇸", "MT": "🇲🇹", "MU": "🇲🇺", "MV": "🇲🇻", "MW": "🇲🇼", "MX": "🇲🇽", "MY": "🇲🇾", "MZ": "🇲🇿", "NA": "🇳🇦", "NC": "🇳🇨", "NE": "🇳🇪", "NF": "🇳🇫", "NG": "🇳🇬", "NI": "🇳🇮", "NL": "🇳🇱", "NO": "🇳🇴", "NP": "🇳🇵", "NR": "🇳🇷", "NU": "🇳🇺", "NZ": "🇳🇿", "OM": "🇴🇲", "PA": "🇵🇦", "PE": "🇵🇪", "PF": "🇵🇫", "PG": "🇵🇬", "PH": "🇵🇭", "PK": "🇵🇰", "PL": "🇵🇱", "PM": "🇵🇲", "PN": "🇵🇳", "PR": "🇵🇷", "PS": "🇵🇸", "PT": "🇵🇹", "PW": "🇵🇼", "PY": "🇵🇾", "QA": "🇶🇦", "RE": "🇷🇪", "RO": "🇷🇴", "RS": "🇷🇸", "RU": "🇷🇺", "RW": "🇷🇼", "SA": "🇸🇦", "SB": "🇸🇧", "SC": "🇸🇨", "SD": "🇸🇩", "SE": "🇸🇪", "SG": "🇸🇬", "SH": "🇸🇭", "SI": "🇸🇮", "SJ": "🇸🇯", "SK": "🇸🇰", "SL": "🇸🇱", "SM": "🇸🇲", "SN": "🇸🇳", "SO": "🇸🇴", "SR": "🇸🇷", "SS": "🇸🇸", "ST": "🇸🇹", "SV": "🇸🇻", "SX": "🇸🇽", "SY": "🇸🇾", "SZ": "🇸🇿", "TC": "🇹🇨", "TD": "🇹🇩", "TF": "🇹🇫", "TG": "🇹🇬", "TH": "🇹🇭", "TJ": "🇹🇯", "TK": "🇹🇰", "TL": "🇹🇱", "TM": "🇹🇲", "TN": "🇹🇳", "TO": "🇹🇴", "TR": "🇹🇷", "TT": "🇹🇹", "TV": "🇹🇻", "TW": "🇹🇼", "TZ": "🇹🇿", "UA": "🇺🇦", "UG": "🇺🇬", "UM": "🇺🇲", "US": "🇺🇸", "UY": "🇺🇾", "UZ": "🇺🇿", "VA": "🇻🇦", "VC": "🇻🇨", "VE": "🇻🇪", "VG": "🇻🇬", "VI": "🇻🇮", "VN": "🇻🇳", "VU": "🇻🇺", "WF": "🇼🇫", "WS": "🇼🇸", "YE": "🇾🇪", "YT": "🇾🇹", "ZA": "🇿🇦", "ZM": "🇿🇲", "ZW": "🇿🇼"
]

Another function for turning a two-letter country code into its emoji flag using Swift 5.

internal func getFlag(from countryCode: String) -> String {
    countryCode
        .unicodeScalars
        .map({ 127397 + $0.value })
        .compactMap(UnicodeScalar.init)
        .map(String.init)
        .joined()
}

Swift turn a country code into a emoji flag via unicode

Related

Recent Posts