Ansæt senior og gennemprøvede Objective-C-udviklere

As many developers will tell you, Objective-C has been a pillar in the development landscape for many years, offering a robust and mature environment for building a wide range of applications, predominantly for macOS and iOS platforms. This object-oriented programming language brought a new depth to C, adding messaging and runtime reflection, which are crucial for today's dynamic applications.

Objective-C is a resilient language that has stood the test of time.

What sets Objective-C apart is its deep integration and history with Apple’s ecosystem. It enables developers to build highly efficient yet sophisticated applications with a well-established base of tools and community resources. It is a language that embraces simplicity and power, providing a fertile ground for experienced developers to craft intricate solutions.

Objective-C was developed in the early 1980s, standing as a critical component in Apple's development ecosystem until Swift took center stage. Despite this, it remains a popular choice for maintaining existing applications and leveraging a substantial legacy of frameworks and libraries.

"Objective-C's primary strength lies in its mature, stable, and tested frameworks, which allow developers to build secure and robust applications. Moreover, it offers interoperability with C and Swift, facilitating transition and co-existence in complex projects.

Objective-C continues to hold a place in the developer community, supporting legacy projects and offering a deep well of resources and knowledge. According to the Stack Overflow Developer Survey 2023, many developers still prefer Objective-C for its stability and robustness, especially when dealing with large-scale and legacy projects.

Industries & applications

Objective-C is pivotal in sustaining legacy systems across numerous industries, including finance, healthcare, telecommunications, and more. It plays a crucial role in the tech infrastructures of eCommerce platforms, enterprise software solutions, and gaming industries. Despite being superseded by Swift for new projects, it remains indispensable in managing and updating the foundational systems of various business domains.

Must have technical skills for Objective-C Developers

Look for the following skills and technical abilities in your Objective-C candidates' resumes:

• Proficiency in Objective-C language syntax and structure.
• Experience working with frameworks such as UIKit and Foundation.
• Strong understanding of memory management, including Automatic Reference Counting (ARC).
• Skills in working with Objective-C runtime, including a deep understanding of categories, protocols, and selectors.
• Familiarity with design patterns such as MVC, Singleton, and Delegate.

Nice-to-have technical skills for Objective-C Developers

Here is what will set apart the real diamonds in the rough from everyone else in your pool of candidates:

• Experience with Swift and being able to work in a mixed-code base.
• Knowledge of continuous integration and continuous deployment (CI/CD) pipelines.
• Familiarity with unit testing and UI testing in Xcode.
• Knowledge of Apple's Human Interface Guidelines for crafting user-centric designs.

Interview questions and their expected answers

Here are some essential questions you can ask your candidates during the interview. We also answered them for you so you know what kind of answer to expect and vet their capabilities accordingly.

1. Question: Can you explain what Automatic Reference Counting (ARC) is?

Answer: ARC is a compiler feature that provides automatic memory management of Objective-C objects, effectively helping to manage the memory usage of an application reducing the need for manual memory management through retain and release.

2. Question: What is the difference between a class method and an instance method in Objective-C?

Answer: A class method is associated with the class itself and can be called on the class, whereas an instance method is associated with an instance of the class and can only be called on an instance of the class.

3. Question: Can you describe what a category is in Objective-C?

Answer: A category allows developers to add methods to existing classes without modifying the original class, promoting code reusability and organization.

4. Question: What is the significance of the @synthesize directive in Objective-C?

Answer: The @synthesize directive generates setter and getter methods for properties. This is done to access instance variables in a class. Before the advent of the modern Objective-C runtime, developers needed to synthesize properties explicitly, but now it's often done automatically.

5. Question: Can you explain what blocks are and how they are used in Objective-C?

Answer: Blocks are a type of anonymous function or closure in Objective-C. They can capture and store references to variables from the surrounding context, making them a useful tool for creating lightweight, reusable chunks of code. Blocks are often used as callbacks or to encapsulate small units of work that will be executed concurrently or later.

6. Question: What is the difference between @interface and @implementation in Objective-C?

Answer: @interface is used to declare the class interface, which includes the properties and methods that can be used publicly. On the other hand, @implementation defines the actual implementation of the class, containing the code for the methods declared in the @interface.

7. Question: What is the significance of the dealloc method in Objective-C?

Answer: The dealloc method is used to deallocate the memory occupied by an object. Before Automatic Reference Counting (ARC) was introduced, developers needed to override dealloc to release the memory of instance variables and to relinquish ownership of other objects. With ARC, the dealloc method is less commonly overridden, but it may still be necessary to release resources other than memory.

8. Question: What is Key-value coding (KVC), and how is it used in Objective-C?

Answer: Key-value coding is a mechanism by which an object's properties can be accessed using string identifiers at runtime instead of having to know the property names at compile time statically. This feature adds dynamism and flexibility, allowing for more generic code and data-driven behaviors.

9. Question: Explain the Model-View-Controller (MVC) design pattern and how it applies to Objective-C programming.

Answer: The Model-View-Controller (MVC) design pattern separates an application into three interconnected components: the Model (data), the View (user interface), and the Controller (logic). In Objective-C, MVC is a foundational design pattern that helps organize code in a clean, modular, and understandable way, facilitating the separation of concerns.

10. Question: What are protocols in Objective-C, and why are they important?

Answer: Protocols in Objective-C define a blueprint of methods, properties, and other requirements for a particular task or functionality. They allow classes to adopt and conform to these blueprints, facilitating a form of multiple inheritances in a language that doesn’t support it directly. Protocols are crucial for defining expected behaviors and ensuring different classes can work together predictably.

Business benefits of Objective-C/iOS

If you and your team are wondering why exactly your next projects need to be built on Objective-C or its parent technology, iOS, here are some of the main benefits these technologies bring.

• Stability: Objective-C benefits from decades of use, resulting in a stable and mature language for app development. * Rich libraries: It has a rich set of well-tested libraries and frameworks, aiding faster development cycles.
• Legacy project maintenance: It is indispensable in maintaining and updating legacy projects, ensuring the longevity and functionality of older applications.

Qualifications and skills an Objective-C Developer must have

So, what have we learned? Probably, that the vetting and testing of Objective-C developers isn't a piece of cake. You also learned that your search will take longer if a project is more demanding and you need a veteran developer. And we can help you with matching you with a skilled Objective-C developer in only two days.

However, if you still want to do it the more challenging way and hire a developer internally, always look for:

• Experience: Hands-on experience working with Objective-C, ideally evidenced through a portfolio of projects.
• Object-oriented programming: A deep understanding of object-oriented programming concepts and the ability to apply them effectively while writing Objective-C code.
• SOLID Principles: Familiarity with SOLID principles to craft maintainable and robust software architectures.
• Problem-solving skills: Strong analytical and problem-solving skills to troubleshoot and optimize existing codebases.
• Collaborative skills: Ability to work well in a team, leveraging knowledge of version control systems and other collaborative tools.
• Eye for design: A discerning eye for "pixel-perfect" design, ensuring the end product aligns seamlessly with the design specifications and provides an exceptional user experience.