How do I use NSRange with this NSString?

Question

I have the following NSString:

productID = @\"com.sortitapps.themes.pink.book\";

At the end, \"book\" can be anything.... \"music\

Answer 1

You can use -[NSString componentsSeparatedByString:@"."] to split into components, create a new array with your desired values, then use [NSArray componentsJoinedByString:@"."] to join your modified array into a string again.

Answer 2

You can try a backward search for the dot and use the result to get the desired range:

NSString *str = @"com.sortitapps.themes.pink.book";
NSUInteger dot = [str rangeOfString:@"." options:NSBackwardsSearch].location;

NSString *newStr =
   [str stringByReplacingCharactersInRange:NSMakeRange(dot+1, [str length]-dot-1)
                                withString:@"something_else"];

Answer 3

Well, although this isn't a generic solution for finding characters, in your particular case you can "cheat" and save code by doing this:

[productID stringByDeletingPathExtension];

Essentially, I'm treating the name as a filename and removing the last (and only the last) extension using the NSString method for this purpose.