“incomplete universal character name” with stringW

问题:

when i try to convert form utf-8 string to NSString like so:

NSString *s = [NSString stringWithUTF8String:"\U0627\U0644\U0641\U0631\U0646"];
NSLog(@"%@", s);

i get the compile error:

incomplete universal character name

note that it sometime just works fine:

NSString *UAE = [NSString stringWithUTF8String:"\U0627\U0644\U0641\U0631\U0646"];
    NSLog(@"%@", UAE);

and the output:

الامارات

so why is that happening? please help.

回答1:

\U and \u are not the same thing. The \U escape expects 8 (hex) digits instead of 4.

This should work:

NSString *s = [NSString stringWithUTF8String:"\u0627\u0644\u0641\u0631\u0646"];

回答2:

incomplete universal character name means that you are missing part of one of the utf8 character that you are trying to write.

UTF8 spans from 1 byte symbols to 4 byte symbols, probably one of yours is longer that you wrote and you are missing 1 byte or such..