(lldb) p [@"ΗΙzzz" caseInsensitiveCompare:@"ᾚabc"]
(long long) -1
(lldb) p [@"ᾚabc" caseInsensitiveCompare:@"ΗΙzzz"]
(long long) -1
Note the unicode char in the second string. The results can't be both -1, afaik, if one is -1 the other one should be +1.
This causes inconsistent indexing in a sorted array resulting in obscure crashes of my app.
Am I doing something wrong?
Tested on iOS 27 and macOS 26.6.
Tried switching to localizedCaseInsensitiveCompare, though that has similar issues
NSString *a = @"\u1F28\u0399abc"; // ἨΙabc
NSString *b = @"\u1F2E\u0399zzz"; // ἮΙzzz
[a localizedCaseInsensitiveCompare:b] == NSOrderedDescending; // YES
[b localizedCaseInsensitiveCompare:a] == NSOrderedDescending; // YES
NSString *c = @"\u0397\u0313\u0345abc"; // ᾘabc
NSString *d = @"\u1F28\u0399abc"; // ἨΙabc
[c localizedCaseInsensitiveCompare:d] == NSOrderedAscending; // YES
[d localizedCaseInsensitiveCompare:c] == NSOrderedSame; // YES
Really getting confused here...
Feedback Assistant: FB24975737
Yeah, string ordering is hard in the general case. I think it’s reasonable to file a bug about the behaviour you’re seeing, so thanks for FB24975737. As to what you can do about it right now, I want to ask about this:
This causes inconsistent indexing in a sorted array resulting in obscure crashes of my app.
What are you creating this array for? Is it a temporary thing that only exists in memory and it used, say, to present a sort list of items to the user? Or are you using it for something more persistent? Or something that’s internal, so not being displayed to the user.
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Quinn “The Eskimo!” @ Developer Technical Support @ Apple
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