Find Unicode / Emoji flag based on country code in Swift 5

UnicodeFlag.swift

func unicodeFlag(countryCode: String) -> String {
    // expects a 2-letter ISO code of the country
    
    // Unicode flags are generated by taking the 2 letter ISO code of the country
    // and mapping them to the regional indicator symbols. Font ligatures are used
    // to make them into a single glymph. A more detailed explanation is available
    // here -> https://esham.io/2014/06/unicode-flags
    
    // This code is based on this stackoverflow answer for Java
    // https://stackoverflow.com/questions/30494284/android-get-country-emoji-flag-using-locale/35849652#35849652
        
    
    let flagOffset: UInt32 = 0x1F1E6    // REGIONAL INDICATOR SYMBOLS starting point ("A")
    
    let asciiOffset: UInt32 = 0x41      // ASCII START

    var flag = ""
    
    // Split the symbols into their scalars
    for scalar in countryCode.unicodeScalars {
        // Compute the regional indicator symbol scalar
        flag.append(String(Unicode.Scalar(scalar.value - asciiOffset + flagOffset)!))
    }
    
    return flag
}

print(unicodeFlag(countryCode: "IN"))
print(unicodeFlag(countryCode: "SE"))
print(unicodeFlag(countryCode: "DE"))
print(unicodeFlag(countryCode: "SC"))

/*
 Output:
 🇮🇳
 🇸🇪
 🇩🇪
 🇸🇨
*/