如何将两个字母的国家代码映射到表情符号？

Question

Anyone fiddled with https://en.wikipedia.org/wiki/Regional_Indicator_Symbol? I am wondering how to get US printed as a flag

Answer 1

The only improvements I would recommend is adding verification that the input characters is a pair of ASCII uppercase letters. Here is an example of what the template function would look like:

func(x string) (string, error) {

    if len(x) != 2 {

        return "", errors.New("country code must be two letters")

    }

    if x[0] < 'A' || x[0] > 'Z' || x[1] < 'A' || x[1] > 'Z' {

        return "", errors.New("invalid country code")

    }

    return string('