objective-c string manipulation

Question

I have a string "AA - The Title of the Person"

How can I get the part before the '-'?

The output should be "AA"

Also if the input doesn't have a '-' then output should be nil

Answer 1

NSInteger hyphenStart = [theString rangeOfString:@" - "].location;
if(hyphenStart == NSNotFound)
    return nil;
return [theString substringToIndex:hyphenStart];

Answer 2

阅读NSString类文档。