iphone - Unicode Character from Code in String (Obj-C)

Question

I have a unicode hex value in an NSString - how do I output the character; here's what I have:

NSLog(@"U0001D000");

NSMutableString *hexString = [[NSMutableString alloc] initWithString:@"0001D000"];
[hexString insertString:@"\U" atIndex:0];
NSLog(@"%@", hexString);

The first NSLog outputs the character; the second just produces the output "U0001D000"

I've tried lots of combinations and am at a loss - for example, I tried

NSLog(@"U%@", hexString);

But this gives a complier error, as it is looking for a string of numbers after the U

Answer 1

If your character requires a surrogate pair (U+10000 to U+10FFFF), use CFStringGetSurrogatePairForLongCharacter to convert the Unicode code point into a UTF-16 surrogate pair, and then -initWithCharacters:length: to convert it into an NSString. For example:

UniChar c[2];
CFStringGetSurrogatePairForLongCharacter(0x1D000, c);
NSString *s = [[NSString alloc] initWithCharacters:c length:2];

For other characters (CFStringGetSurrogatePairForLongCharacter returns FALSE), you can skip the conversion and go straight to -initWithCharacters:length:.