iOS is an operating system developed by Apple Inc., and is used to power its mobile devices such as the iPhone, iPad and iPod Touch. It is the second most popular mobile platform after Android, and is used by millions of people around the world. But what code is iOS written in?
The short answer is that iOS is written in C and Objective-C, with some parts of the operating system written in Swift and other languages. C is a general-purpose programming language that was developed in the 1970s and is a low-level language, meaning it’s close to machine code and is relatively easy for a computer to understand. Objective-C is a language created by adding object-oriented features to C, and was first used in the NeXTSTEP operating system which was later acquired by Apple and used to develop iOS. Swift is a high-level language developed by Apple in 2014, which is easier for humans to read and understand, and is used for writing applications that run on the iOS operating system. Additionally, other languages such as Java, JavaScript, and HTML5 are used in the development of iOS, but are usually used for writing applications that run on the operating system rather than the operating system itself.