Question

I’ve got an international character stored in a unichar variable. This character does not come from a file or url. The variable itself only stores an unsigned short(0xce91) which is in UTF-8 format and translates to the greek capital letter ‘A’. I’m trying to put that character into an NSString variable but i fail miserably.

I’ve tried 2 different ways both of which unsuccessful:

unichar greekAlpha = 0xce91; //could have written greekAlpha = 'Α' instead.

NSString *theString = [NSString stringWithFormat:@"Greek Alpha: %C", greekAlpha];

No good. I get some weird chinese characters. As a sidenote this works perfectly with english characters.

Then I also tried this:

NSString *byteString = [[NSString alloc] initWithBytes:&greekAlpha
                                                length:sizeof(unichar)
                                              encoding:NSUTF8StringEncoding];

But this doesn’t work either.
I’m obviously doing something terribly wrong, but I don’t know what.
Can someone help me please ?
Thanks!

Answer 1

Since 0xce91 is in the UTF-8 format and %C expects it to be in UTF-16 a simple solution like the one above won’t work. For stringWithFormat:@"%C" to work you need to input 0x391 which is the UTF-16 unicode.

In order to create a string from the UTF-8 encoded unichar you need to first split the unicode into it’s octets and then use initWithBytes:length:encoding.

unichar utf8char = 0xce91; 
char chars[2];
int len = 1;

if (utf8char > 127) {
    chars[0] = (utf8char >> 8) & (1 << 8) - 1;
    chars[1] = utf8char & (1 << 8) - 1; 
    len = 2;
} else {
    chars[0] = utf8char;
}

NSString *string = [[NSString alloc] initWithBytes:chars
                                            length:len 
                                          encoding:NSUTF8StringEncoding];