Objective-C iOS Development for Legacy & Enterprise Apps · Lesson

Table Views and Collection Views

Implement and customize UITableView and UICollectionView for displaying dynamic lists and grids of content.

Table Views and Collection Views is a free Objective-C iOS Development for Legacy & Enterprise Apps lesson on CoddyKit — lesson 3 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the Objective-C iOS Development for Legacy & Enterprise Apps learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.

Meet UITableView

Welcome to lists! UITableView is a fundamental UIKit component used to display scrollable lists of data, commonly seen in apps for settings, contacts, or news feeds.

It's optimized for efficiency, only rendering the cells visible on screen, which makes it perfect for long lists without performance issues.

Data & Behavior for Tables

To work with a UITableView, you primarily interact with two protocols:

UITableViewDataSource: This tells the table view what data to display (e.g., number of rows, content for each cell).
UITableViewDelegate: This handles how the table view behaves (e.g., row selection, height of rows, custom actions).

Your view controller typically conforms to both.

Your First Table View

Let's create a basic UITableView programmatically. This code snippet assumes it's within a UIViewController subclass that is set as the app's root view controller.

We add the table view to our controller's main view, making it fill the screen.

#import <UIKit/UIKit.h>

@interface MyTableViewController : UIViewController
@end

@implementation MyTableViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    self.view.backgroundColor = [UIColor whiteColor];
    
    // Create a UITableView filling the view
    UITableView *tableView = [[UITableView alloc] initWithFrame:self.view.bounds style:UITableViewStylePlain];
    tableView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
    
    // We'll set the data source and delegate in next steps
    // tableView.dataSource = self; 
    
    [self.view addSubview:tableView];
}
@end

Populating Your Table

To display data, our MyTableViewController needs to conform to the UITableViewDataSource protocol. This means implementing two key methods:

numberOfRowsInSection: Tells the table how many rows to expect.
cellForRowAtIndexPath: Provides the UITableViewCell for each row.

We also register a basic UITableViewCell for reuse.

#import <UIKit/UIKit.h>

@interface MyTableViewController : UIViewController <UITableViewDataSource>
@property (nonatomic, strong) NSArray *dataItems;
@property (nonatomic, strong) UITableView *tableView;
@end

@implementation MyTableViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    self.view.backgroundColor = [UIColor whiteColor];
    self.dataItems = @[@"Apple", @"Banana", @"Cherry", @"Date"];
    
    self.tableView = [[UITableView alloc] initWithFrame:self.view.bounds style:UITableViewStylePlain];
    self.tableView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
    self.tableView.dataSource = self; // Set self as data source
    
    // Register a basic UITableViewCell class for reuse
    [self.tableView registerClass:[UITableViewCell class] forCellReuseIdentifier:@"Cell"];
    
    [self.view addSubview:self.tableView];
}

#pragma mark - UITableViewDataSource methods

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    return self.dataItems.count; // Number of items in our data array
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    // Dequeue (reuse) or create a cell
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"Cell" forIndexPath:indexPath];
    cell.textLabel.text = self.dataItems[indexPath.row]; // Set cell's text
    return cell;
}
@end

Making Cells Unique

UITableViewCell is the view that displays content for each row. You can customize its appearance by:

Using built-in styles (e.g., UITableViewCellStyleSubtitle).
Adding subviews directly to cell.contentView.
Creating a custom subclass of UITableViewCell for complex layouts.

Always reuse cells with dequeueReusableCellWithIdentifier: for performance.

#import <UIKit/UIKit.h>

@interface MyTableViewController : UIViewController <UITableViewDataSource>
@property (nonatomic, strong) NSArray *dataItems;
@property (nonatomic, strong) UITableView *tableView;
@end

@implementation MyTableViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    self.view.backgroundColor = [UIColor whiteColor];
    self.dataItems = @[@"Apple", @"Banana", @"Cherry", @"Date"];
    
    self.tableView = [[UITableView alloc] initWithFrame:self.view.bounds style:UITableViewStylePlain];
    self.tableView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
    self.tableView.dataSource = self;
    // Registering a cell class (we'll use the default for demo)
    [self.tableView registerClass:[UITableViewCell class] forCellReuseIdentifier:@"CustomCell"];
    
    [self.view addSubview:self.tableView];
}

#pragma mark - UITableViewDataSource methods

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    return self.dataItems.count;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    // Dequeue a cell, using UITableViewCellStyleSubtitle for more options
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"CustomCell" forIndexPath:indexPath];
    
    cell.textLabel.text = self.dataItems[indexPath.row];
    cell.detailTextLabel.text = [NSString stringWithFormat:@"Item #%ld", (long)indexPath.row + 1];
    cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator; // Add an arrow
    
    return cell;
}
@end

Flexible Grids: UICollectionView

While UITableView excels at vertical lists, UICollectionView offers much more flexibility for displaying content in customizable layouts, like grids, carousels, or complex dashboards.

It's ideal when you need to arrange items in non-linear or highly visual ways, such as photo galleries, product catalogs, or tag clouds.

Collection View's Data & Flow

Similar to table views, collection views rely on a UICollectionViewDataSource to provide data and a UICollectionViewDelegate for interaction.

A key difference is the UICollectionViewLayout. This object defines how items are arranged (e.g., grid, flow, custom). The most common is UICollectionViewFlowLayout for grid-like structures.

Building Your First Collection

Let's set up a basic UICollectionView. We'll also need to provide a UICollectionViewLayout to tell it how to arrange its items.

UICollectionViewFlowLayout is a good starting point for simple grids, allowing you to define item sizes and spacing.

#import <UIKit/UIKit.h>

@interface MyCollectionViewController : UIViewController
@property (nonatomic, strong) UICollectionView *collectionView;
@end

@implementation MyCollectionViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    self.view.backgroundColor = [UIColor whiteColor];
    
    // Create a flow layout for grid arrangement
    UICollectionViewFlowLayout *layout = [[UICollectionViewFlowLayout alloc] init];
    layout.itemSize = CGSizeMake(100, 100); // Size for each item
    layout.minimumInteritemSpacing = 10;    // Min spacing between items in a row
    layout.minimumLineSpacing = 10;         // Min spacing between rows
    
    self.collectionView = [[UICollectionView alloc] initWithFrame:self.view.bounds collectionViewLayout:layout];
    self.collectionView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
    self.collectionView.backgroundColor = [UIColor systemGroupedBackgroundColor]; // For contrast
    
    // We'll set the data source in the next step
    // self.collectionView.dataSource = self;
    
    [self.view addSubview:self.collectionView];
}
@end

Populating Your Collection

To display items, our MyCollectionViewController needs to conform to UICollectionViewDataSource. It's similar to UITableViewDataSource:

numberOfItemsInSection: Specifies the number of items.
cellForItemAtIndexPath: Provides the UICollectionViewCell for each item.

Remember to register a cell class or nib before dequeuing!

#import <UIKit/UIKit.h>

@interface MyCollectionViewController : UIViewController <UICollectionViewDataSource>
@property (nonatomic, strong) NSArray *dataItems;
@property (nonatomic, strong) UICollectionView *collectionView;
@end

@implementation MyCollectionViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    self.view.backgroundColor = [UIColor whiteColor];
    self.dataItems = @[@"Red", @"Green", @"Blue", @"Yellow", @"Orange", @"Purple"];
    
    UICollectionViewFlowLayout *layout = [[UICollectionViewFlowLayout alloc] init];
    layout.itemSize = CGSizeMake(80, 80);
    layout.minimumInteritemSpacing = 5;
    layout.minimumLineSpacing = 5;
    layout.sectionInset = UIEdgeInsetsMake(5, 5, 5, 5); // Padding around sections
    
    self.collectionView = [[UICollectionView alloc] initWithFrame:self.view.bounds collectionViewLayout:layout];
    self.collectionView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
    self.collectionView.backgroundColor = [UIColor systemGroupedBackgroundColor];
    self.collectionView.dataSource = self; // Set self as data source
    
    // Register a basic UICollectionViewCell class
    [self.collectionView registerClass:[UICollectionViewCell class] forCellWithReuseIdentifier:@"CollectionCell"];
    
    [self.view addSubview:self.collectionView];
}

#pragma mark - UICollectionViewDataSource methods

- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {
    return self.dataItems.count;
}

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
    UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"CollectionCell" forIndexPath:indexPath];
    
    // Simple customization: set background color based on item
    NSArray *colors = @[[UIColor redColor], [UIColor greenColor], [UIColor blueColor], [UIColor yellowColor],
                            [UIColor orangeColor], [UIColor purpleColor]];
    cell.backgroundColor = colors[indexPath.item % colors.count];
    
    // Add a label to the cell for text (optional)
    UILabel *label = (UILabel *)[cell.contentView viewWithTag:100];
    if (!label) {
        label = [[UILabel alloc] initWithFrame:cell.contentView.bounds];
        label.tag = 100;
        label.textAlignment = NSTextAlignmentCenter;
        label.textColor = [UIColor whiteColor];
        label.font = [UIFont systemFontOfSize:14];
        [cell.contentView addSubview:label];
    }
    label.text = self.dataItems[indexPath.item];
    
    return cell;
}
@end

Table vs. Collection

Both UITableView and UICollectionView display lists of data, but they have different strengths.

Which of the following is a primary advantage of using UICollectionView over UITableView?

Recap: Lists & Grids

We explored UITableView for displaying efficient vertical lists and UICollectionView for highly customizable grid and non-linear layouts.

Both use Data Source and Delegate protocols to manage content and behavior.
UITableView is simpler for standard, single-column lists.
UICollectionView uses a UICollectionViewLayout for powerful and custom visual arrangements.

Mastering these components is crucial for building dynamic and engaging iOS user interfaces.

Frequently asked questions

Is the “Table Views and Collection Views” lesson free?

Yes — the full text of “Table Views and Collection Views” is free to read here on the web, and the Objective-C iOS Development for Legacy & Enterprise Apps course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the Objective-C iOS Development for Legacy & Enterprise Apps course, upgrade to CoddyKit PRO.

What will I learn in “Table Views and Collection Views”?

Implement and customize UITableView and UICollectionView for displaying dynamic lists and grids of content. You practise Objective-C iOS Development for Legacy & Enterprise Apps with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.

Do I need any experience to start Objective-C iOS Development for Legacy & Enterprise Apps?

No prior experience is required. Objective-C iOS Development for Legacy & Enterprise Apps on CoddyKit is structured for beginners through advanced learners; this is — lesson 3 of 4, so you can start here or from the beginning and move at your own pace.

How long does the “Table Views and Collection Views” lesson take?

Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.

Can I write and run code in this Objective-C iOS Development for Legacy & Enterprise Apps lesson?

Yes. Every Objective-C iOS Development for Legacy & Enterprise Apps lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.

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