how to sort an NSMutableArray of Arrays?

I'm trying to sort an array of a table view with no luck, this is how I'm trying to do it:

    开发者_开发技巧- (void) compare
    {  

        NSMutableArray *temp = [[NSMutableArray alloc] initWithObjects: nil];

        [temp addObjectsFromArray:[self displayedObjects]];


        int a = [[self displayedObjects] count];

        for (int i = 0; i < (a - 1); i++){

            for (int j = 0; j <= (i^2); j++) {

                NSString *temp1 = [temp objectAtIndex:i];

                NSString *temp2 = [temp objectAtIndex:i+1];

                if (temp1 > temp2) {

                    [movieIndex replaceObjectAtIndex:i withObject:temp2];

                    [movieIndex replaceObjectAtIndex:i+1 withObject:temp1];

                }
            }  
        }

        [self movieIndex];

        [[self tableView] reloadData];

    }

displayedObjects is an array of array that the user can add new objects. this objects are movie instances in form of:

The tableview cell has the title of the movie. "in" that title there is a tableview with details about the movie. What i want to do is sort the displayed movies titles in ascending order but my code doesn't seem to work.

displayedObjects is a set of 3 NSStrings and 1 NSNumber. It gets objects form the following class:

#import <Foundation/Foundation.h>

@interface Movie : NSObject
    {
        NSString *_title;
        NSString *_gender;
        NSString *_location;
        NSNumber *_publicationYear;
    }

@property (nonatomic, retain) NSString *location;
@property (nonatomic, retain) NSString *title;
@property (nonatomic, retain) NSString *gender;
@property (nonatomic, retain) NSNumber *publicationYear;

+ (id)movieWithTitle:(NSString *)title
                 gender:(NSString *)gender
                   year:(NSUInteger)year
                location:(NSString *)location;

- (id)initWithTitle:(NSString *)title
                 gender:(NSString *)gender
                   year:(NSUInteger)year
                location:(NSString *)location;

@end

Because no one has suggested it yet, and I personally love blocks, I'll suggest the block alternative to the same thing already suggested:

[myArray sortUsingComparator:^NSComparisonResult(id obj1, id obj2) {
     ...
}];

I made it work by using:

NSSortDescriptor *titleSorter= [[NSSortDescriptor alloc] initWithKey:@"title" ascending:YES];

[movieIndex sortUsingDescriptors:[NSArray arrayWithObject:titleSorter]];