Convert country code (https://en.wikipedia.org/wiki/ISO_3166-1_alpha-2) to Flag emoji using Kotlin functions.

main.kt

fun countryFlag(code: String) = code
  .uppercase()
  .split("")
  .filter { it.isNotBlank() }
  .map { it.codePointAt(0) + 0x1F1A5 }
  .joinToString("") { String(Character.toChars(it)) }

println(countryFlag("in"))
// output 🇮🇳

Oh so you reset it to 0, making it the beginning of the range.
Using joinToString means it's multiple Unicode characters. According to the standard, supposed to always be 2 , no?

If so, this shows why the other implementation seems like this instead:

val firstLetter: Int = Character.codePointAt(countryCodeUpperCase, 0) + 0x1F1A5
val secondLetter: Int = Character.codePointAt(countryCodeUpperCase, 1) + 0x1F1A5
return String(Character.toChars(firstLetter)) + String(Character.toChars(secondLetter))

According to the standard, supposed to always be 2 , no?

Right

If so, this shows why the other implementation seems like this instead:

I wanted to do it in Kotlin way 😅

I see. Thanks.
So if I want to check the values, that it is in the range, each of the 2 characters should be between 0x1F1E6 and 0x1F1FF , right?

That's about the output.
The input should just be between A and Z, right (from AA to ZZ)?

each of the 2 characters should be between 0x1F1E6 and 0x1F1FF , right?

Correct

OK thanks