It is fairly simple to display data in sections in a tableview, if you’re using Core Data and NSFetchedResultsController. But if you have any amount of dynamic data and you want to do this using your own model object system, it is surprisingly not so.

However, it just takes a few additional lines of code to achieve this, and here’s how.

You will need a few additional variables in your tableViewController.

@property (strong, nonatomic) NSMutableArray *sectionsArray;
@property (strong, nonatomic) NSMutableArray *subArrays;

Next, in viewDidLoad:

//Load your model objects in an array:
NSArray *yourData = ... ;

// Extract the values for section titles from your model. [yourData valueForKeyPath:@"path"] extracts only the particular attribute we want into a new array, with which we create an NSSet, so that only unique objects remain. Assuming we want 'categories' as sections:

NSSet *set = [NSSet setWithArray:[yourData valueForKeyPath:@"category"]];

// Create a sortDescriptor in case you need to sort section names
NSSortDescriptor *sort = [NSSortDescriptor sortDescriptorWithKey:nil ascending:YES selector:@selector(caseInsensitiveCompare:)];
	
self.sectionsArray = [NSMutableArray arrayWithArray:[[set allObjects]sortedArrayUsingDescriptors:@[sort]]];
self.subArrays = [NSMutableArray array];
	
//Iterate over each section, and fill with member objects.  

[self.sectionsArray enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
		NSString *category = (NSString*)obj;
// For each section, identify all objects that contain the keyPath we used earlier
		NSArray *subArray = [self.historyArray filteredArrayUsingPredicate:[NSPredicate predicateWithFormat:@"category = %@",category]];
		NSSortDescriptor *sort2 = [NSSortDescriptor sortDescriptorWithKey:@"title" ascending:YES];
		
		subArray = [subArray sortedArrayUsingDescriptors:@[sort2]];

// The subarray is filled with arrays of member objects, each array at an index corresponding to the index of the section.
		[self.subArrays insertObject:subArray atIndex:idx];
	}];
[self.tableView reloadData];

Then setup the tableView, and that’s it:

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

    // Return the number of sections.
    return self.sectionsArray.count;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{

    // Return the number of rows in the section.
    NSArray *subArray = [self.subArrays objectAtIndex:section];
    return subArray.count;
}

-(NSString*)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section{
	return [self.sectionsArray objectAtIndex:section];
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"Cell" forIndexPath:indexPath];
    
	NSArray *subArray = [self.subArrays objectAtIndex:indexPath.section];
	Model *object = [subArray objectAtIndex:indexPath.row];

	cell.textLabel.text = object.title;

    return cell;
}