Change dictionary value

NSDictionary  *tmpDict = [NSDictionary dictionaryWithObjectsAndKeys:

                                      // Object and key pairs

                                      @"2", @"userid",

                                      @"1", @"adminid",

                                      nil];

NSMutableDictionary *mutableDict = [tmpDict mutableCopy];

 [mutableDict setObject:@"2" forKey:@"adminid"];

  tmpDict = [mutableDict mutableCopy];

Newly add one key in NSDictionary:

NSMutableDictionary *mutableDict = [tmpDict mutableCopy];

 [mutableDict setObject:@"1" forKey:@"extra"];

  tmpDict = [mutableDict mutableCopy];

remove more than one object in array

NSMutableIndexSet *indexesToDelete = [NSMutableIndexSet indexSet];

        NSArray *deassMatches = [pickerArray valueForKey:eventstr.task_picker_id_str];

        for (int i =0; i<deassignArr.count; i++) {

            if ([deassMatches containsObject:[deassignArr objectAtIndex:i]])

            {

                NSUInteger indexvalue = [deassMatches indexOfObject:[deassignArr objectAtIndex:i]];

                [indexesToDelete addIndex:indexvalue];

            }

        }

        [pickerArray removeObjectsAtIndexes:indexesToDelete];

OR

NSMutableIndexSet *indexesToDelete = [NSMutableIndexSet indexSet];

NSUInteger currentIndex = 0;

for (id obj in yourArray) {

    //do stuff with obj

    if (shouldBeDeleted(obj)) {

        [indexesToDelete addIndex:currentIndex];

    }

    currentIndex++;

}

[yourArray removeObjectsAtIndexes:indexesToDelete];

Get particular index value from NSMutableArray

NSArray *matches = [disObjectArray valueForKey: @"userjid"];

        if ([matches containsObject:notification.object])

        {

            NSUInteger index = [matches indexOfObject:notification.object];

            NSArray *indexPathArray = [NSArray arrayWithObject:[NSIndexPath indexPathForRow:index inSection:0]];

            [friendslistTable reloadRowsAtIndexPaths:indexPathArray withRowAnimation:UITableViewRowAnimationNone];

        }

Call viewcontroller from Appdelegate or UIView

- (UIViewController *)visibleViewController:(UIViewController *)rootViewController

{

    if (rootViewController.presentedViewController == nil)

    {

        return rootViewController;

    }

    if ([rootViewController.presentedViewController isKindOfClass:[UINavigationController class]])

    {

        UINavigationController *navigationController = (UINavigationController *)rootViewController.presentedViewController;

        UIViewController *lastViewController = [[navigationController viewControllers] lastObject];

        

        return [self visibleViewController:lastViewController];

    }

    if ([rootViewController.presentedViewController isKindOfClass:[UITabBarController class]])

    {

        UITabBarController *tabBarController = (UITabBarController *)rootViewController.presentedViewController;

        UIViewController *selectedViewController = tabBarController.selectedViewController;

        

        return [self visibleViewController:selectedViewController];

    }

    UIViewController *presentedViewController = (UIViewController *)rootViewController.presentedViewController;

    

    return [self visibleViewController:presentedViewController];

}

// Call viewcontroller

       UIViewController *vc = [self visibleViewController:[UIApplication sharedApplication].keyWindow.rootViewController];

        

        NextViewController *next = [[NextViewController alloc]initWithNibName:@"NextViewController" bundle:nil];

        [vc presentViewController:next animated:YES completion:nil];