iOS cell delegate

//MyCell.h

@protocol MyCellDelegate <NSObject>

-(void)cellCheckBoxWasChanged:(MyCell *)cell;

@end

@interface MyCell : NSObject

@property (nonatomic, weak) id <MyCellDelegate> delegate;

@end

***
//MyCell.m

@implementation MyCell

- (void)checkBoxChanged
{
    [self.delegate cellCheckBoxWasChanged:self];
}

@end

***-*-*---
//TableViewController.m

- (void)cellCheckBoxWasChanged:(MyCell *)cell
{
    NSIndexPath *indexPath = [self.tableView indexPathForCell:cell];

    // do something to your array.
}