Objective-C

Why learn Objective-C in a Swift-dominated world?

Although Swift dominates iOS development in today's landscape, learning Objective-C is still relevant and can be the key to a job as an iOS developer. Despite the fact that Objective-C, a programming language created over 40 years ago, may seem old-fashioned, it is still necessary to understand the structure behind many older apps and have an edge in the job market. Mastering Objective-C will allow you not only to create apps, but also to understand and modify legacy applications that might be composed of both languages.

How to create a basic Objective-C project?

To start your journey in Objective-C, creating a new project is essential. Here we show you a step-by-step to prepare the ground:

1. Create a new project:

   • Select the "Single View App" template.
   • Choose Objective-C as the language.
   • Save the project in an accessible place, such as the desktop.

2. Project structure in Objective-C:

   • Files are divided into .h for the public interface and .m for the implementation.
   • It includes AppDelegate and ViewController similar to Swift projects.

When creating a new project, you will notice that there are more files than in Swift, due to the separate use of interface and implementation files, which can be overwhelming at first. However, having this clear structure is crucial for understanding how the different parts of the code relate to each other.

How to work with interfaces and classes in Objective-C?

Objective-C has some notable differences from Swift in the way interfaces and classes are handled. For starters, it's important to understand how these connections are established in your code:

• Use @interface and @implementation to define classes.
• Methods and properties should be declared in the .h file and defined in the .m file.

One aspect that stands out is the use of the asterisk ( * ) as a memory pointer, necessary for the declaration of variables.

Example of connection with an outlet in Objective-C

@interface ViewController : UIViewController@property (nonatomic, weak) IBOutlet UITableView *tableView;@end

@implementation ViewController- (void)viewDidLoad { [super super viewDidLoad]; [self setupUI];}
 -(void)setupUI { self.tableView.dataSource = self;}@end

Here is an important difference with Swift in terms of interface handling: in Objective-C, you need to manually implement many of the features that in Swift are automatically configured.

How to manage tables and cells in Objective-C?

Creating a basic user interface with tables in Objective-C is not much different from Swift, once you understand the basics. Here's a quick guide to setting up a table:

1. Add TableView from Storyboard:

   • Drag a TableView from the object library to your screen.
   • Define constraints to position it properly.

2. Implement datasource methods:

   • Implement UITableViewDataSource in the .h file.
   • Add methods in the .m to define the number of rows and cell characteristics.

Code to manage cells

-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section { return 10; // Number of cells}
 -(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"CellID" forIndexPath:indexPath]; cell.textLabel.text = @"I am a cell"; return cell;}

This example highlights the use of Swift-like methods, but with a syntax that reflects the age and unique features of Objective-C.

What are the challenges and benefits of learning Objective-C?

Learning Objective-C can be challenging due to its different syntax and approaches than Swift, but its benefits include:

• Access to legacy software: Many existing applications still work with Objective-C.
• Expanding your skills: It makes you a more versatile and competitive developer.
• Understanding the origins of iOS: It gives you a deeper understanding of the Apple ecosystem.

The path to mastering Objective-C is both a challenge and an opportunity for personal and professional growth. Although at first you may be scared by its structure and fine details, such as the need to handle pointers and differentiate between interface and implementation files, facing these challenges will help you grow as a developer, better preparing you for the iOS job market.