The iOS operating system is a proprietary mobile operating system created and maintained by Apple Inc. iOS is the second most popular mobile operating system in the world, behind only Android. Apple’s iOS was first introduced in 2007 and has since been updated several times, with the latest version being iOS 14.5, released in 2021. But what programming language is iOS written in, and how does it work?

iOS, the mobile operating system developed by Apple, primarily uses the programming language called Swift. However, Objective-C, another programming language, is still supported and used in some iOS applications. In general, the iOS ecosystem supports various programming languages such as C, C++, and JavaScript, among others. In this way, developers can choose the most appropriate language for their specific needs when building iOS applications.

The Basics of iOS Programming


Objective-C is a high-level programming language that is based on the C programming language. It was developed in the early 1980s by Brad Cox and Tom Love. Objective-C is an object-oriented programming language, which means that it uses objects to represent data and methods to manipulate that data. Objective-C is the primary programming language used by Apple for developing iOS and Mac OS X applications.

Objective-C is a strict superset of the C programming language. This means that any valid C program is also a valid Objective-C program. Objective-C adds object-oriented programming capabilities to the C language. Objective-C programs are compiled into machine code by the Objective-C compiler.


Swift is a general-purpose, compiled programming language developed by Apple Inc. for iOS, macOS, watchOS, tvOS, and Linux. Swift is designed to work with Apple’s Cocoa and Cocoa Touch frameworks and the large body of existing Objective-C code written for Apple products.

Swift is a fast, safe, and modern programming language that is easier to read and write than Objective-C. Swift is designed to be more developer-friendly than Objective-C, with a syntax that is easier to read and write. Swift is designed to be more secure than Objective-C, with features that make it easier to write secure code.

How iOS Works

iOS Architecture

  • Cocoa Touch layer
  • Media layer
  • Core Services layer
  • Core OS layer

The Cocoa Touch layer provides the user interface framework for iOS. It includes the UIKit and Foundation frameworks, which provide the basic building blocks for iOS applications.

The Media layer provides support for audio and video playback, as well as support for graphics and animation.

The Core Services layer provides access to system services, such as location services and networking.

The Core OS layer provides the low-level services that the other layers depend on. This includes the kernel, drivers, and other low-level services.

iOS Apps

FAQs: What Language Does iOS Use?

What programming language does iOS use?

iOS uses a programming language called Swift, which is developed by Apple. Swift is a modern and powerful language that is designed to be easy to learn and use. It is a safe, fast, and interactive language that is built for modern iOS development. Swift has quickly become the preferred programming language for iOS app development because of its simplicity, efficiency, and low-level control.

Was Objective-C used in developing iOS?

Yes, Objective-C was the original programming language used for developing iOS applications before Swift was introduced. Objective-C is a high-level, object-oriented programming language that is based on C language. It was also developed by Apple and was the primary language used for iOS app development for over a decade. However, Swift has now taken over as the primary language for iOS development because of its many benefits.

What are the advantages of using Swift for iOS development?

One of the main advantages of using Swift for iOS development is its simplicity. Swift is easy to learn and use, which means developers can quickly start building iOS applications. Swift is also fast and efficient, which means apps built with Swift can run faster and use less battery. Additionally, Swift is a safe language that is designed to prevent common programming errors, which makes it easier for developers to write bug-free code.

Can I still use Objective-C for iOS development?

Yes, you can still use Objective-C for iOS development. Although Swift is now the primary language used for iOS app development, Objective-C is still a widely used language for iOS development. Many iOS applications were written in Objective-C, and developers continue to maintain and update these apps using the language. However, it is recommended that developers learn Swift to take advantage of its many benefits and stay current with modern iOS development techniques.

What other languages are used in iOS development?

Other programming languages that are used in iOS development include C, C++, and JavaScript. C is a low-level programming language that is used for optimizing performance and writing system-level code. C++ is an object-oriented programming language that is used for developing games and other performance-intensive applications. JavaScript is a high-level programming language that is used for building web applications and adding interactivity to iOS apps through web views. However, Swift is the primary language used for iOS application development.

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