How to convert Unicode strings (\u00e2, etc) into NSString for display?

Question

I am trying to support arbitrary unicode from a variety of international users. They have already put a bunch of data into sqlite databases on their iPhones, and now I want

Answer 1

All NSStrings are Unicode.

The problem with the “Frank\u00e2\u0080\u0099s iPad” data isn't that it's Unicode; it's that it's escaped to ASCII. “Frank’s iPad” is valid Unicode in any UTF, and is what you need.

So, you need to see whether the database is returning the data escaped or the PHP layer is escaping it at some point. If either of those is the case, fix it if you can; the PHP resource should return UTF-8/16/32. Only if that approach fails should you seek to unescape the string on the Cocoa side.

You're correct that there is no built-in way to unescape the string in Cocoa. If you get to that point, see if you can find some open-source code to do it; if not, you'll need to do it yourself, probably using NSScanner.