Reload UITableView except one section of it

Question

I have a tableView with multiple sections.
Now I want to reload all sections of tableView except the first one (because it's static and doesn't change).

I now I can reload sections by this method:

reloadSections(IndexSet, with: UITableView.RowAnimation)

but it requires the number of sections and in my app this is dynamic and changes in time.
I can only say reload whatever exist after first section.

I thought I should define a IndexSet somehow like this:

NSIndexSet *indexSet = [NSIndexPath indexPathWithIndexes:(NSUInteger[]){1, ... } length:???];

and I don't know how can I do that!

Any ideas or suggestion would be greatly appreciated.

update

This is the numberOfSectionsInTableView implementation:

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView{

    // Inbox Segment
    if (self.selectedIndex == 0) {
        if (self.inboxArray.count > 0) {
            return self.inboxArray.count + 2;
        }
    }

    // Sent Segment
    else if (self.selectedIndex == 1) {
        if (self.sentArray.count > 0) {
            return self.sentArray.count + 2;
        }
    }

    // Outbox Segment
    else if (self.selectedIndex == 2) {
        if (self.outboxArray.count > 0) {
            return self.outboxArray.count + 2;
        }
    }

    // Spam Segment
    else if (self.selectedIndex == 3) {
        if (self.spamArray.count > 0) {
            return self.spamArray.count + 2;
        }
    }

    // Trash Segment
    else if (self.selectedIndex == 4) {
        if (self.trashArray.count > 0) {
            return self.trashArray.count + 2;
        }
    }
    return 1;
}

Answer 1

Assuming you know the amount of sections:

NSIndexSet *sectionsIndexSet = [NSIndexSet indexSetWithIndexesInRange:NSMakeRange(1, self.sections.count - 1)]
[self.tableView reloadSections:sectionsIndexSet withRowAnimation:UITableViewRowAnimationNone];

Swift:

let sectionsIndexSet = IndexSet(1..<sections.count)
tableView.reloadSections(sectionsIndexSet, with: .none)