NSMutableArray Shuffle Addition

//you can shuffle any NSMutableArray with below code   

//header 

@interface NSMutableArray (Shuffle)

- (void)shuffle;

@end

//implementation 

@implementation NSMutableArray (Shuffle)

- (void)shuffle

{

    static BOOL seeded = NO;

    if(!seeded)

    {

        seeded = YES;

        //srandom is a function that initializes the random number generator.

        srandom(time(NULL));

    }

    NSUInteger count = [self count];

    for (NSUInteger i = 0; i < count; ++i) {

        int arraySize = count - i;

        int n = (random() % arraySize) + i;

        [self exchangeObjectAtIndex:i withObjectAtIndex:n];

    }

}

@end

   .....

- (void)shuffleExapmle:(id)obj {

    NSMutableArray *array=[NSMutableArray arrayWithObjects:@"item 1", @"item2 ", @"item 3", @"item 4", nil];

    [array shuffle];

    ........

    ......