Completed arrays

I have a feeling there is a much better way to write out the following block of code:

```objective-c
- (BOOL) characterArrayContainsWorf:(NSArray *)characterArray {
    /* WORK HERE */
    for (NSString *findWorf in characterArray) {
        NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF CONTAINS 'worf'"];
        [characterArray filteredArrayUsingPredicate:predicate];
    }
    return characterArray;
}
```

Any tips? Moreover, I'm curious as to how I should discover which subclasses I should consider when working through the exercises and code in general.