NSCFArray length]: error, array regex - iphone

Question

StringReply = [[NSString alloc] initWithData:dataReply encoding:NSUTF8StringEncoding];
//Regex Out Artist Name
//NSString *regEx = ;
NSArray *iTunesAristName = [stringReply componentsMatchedByRegex: #"(?<=artistname\":\")([^<]+)(?=\")"];
if ([iTunesAristName isEqual:#""]) {
NSLog(#"Something has messed up");
//Regex Out Song Name
}else{
NSLog(iTunesAristName);
}
NSLog(iTunesAristName);
[stringReply release];
I just keep getting this error ?
2010-09-29 21:15:16.406 [2073:207] *** -[NSCFArray length]: unrecognized selector sent to instance 0x4b0b800
2010-09-29 21:15:16.406 [2073:207] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[NSCFArray length]: unrecognized selector sent to instance 0x4b0b800'
2010-09-29 21:15:16.407 [2073:207] Stack: (
please help its driving me crazy

Answer 1

The first argument to NSLog is supposed to be a format string. You're passing an NSArray. When the function tries to treat your array as a string, you get that error. Instead, use NSLog(#"%#", iTunesAristName);.

Answer 2

Chuck has answered your question, but I've noticed something else that is problematic.
NSArray is an array, not a string, so [iTunesArtistName isEqual:#""] will never return true, because they are different classes. Even if iTunesArtistName was a string, it should be compared using the isEqualToString: method, not isEqual:.
If you want to extract only the artist's name, you might be able to do this:
NSArray *matches = [stringReply componentsMatchedByRegex: #"(?<=artistname\":\")([^<]+)(?=\")"];
if ([matches count] == 0)
{
NSLog(#"Could not extract the artist name");
}
else
{
NSString *iTunesArtistName = [matches objectAtIndex:0];
NSLog(#"Artist name: %#", iTunesArtistName);
}

Answer 3

I see you're using RegexKitLite, make sure you import libicucore.dylib, i was getting the same error until i imported that library.