An Empirical Study on the Usage of the Swift Programming Language

Abstract

Recently, Apple released Swift, a modern programming language built to be the successor of Objective-C. In less than a year and a half after its first release, Swift became one of the most popular programming languages in the world, considering different popularity measures. A significant part of this success is due to Apple’s strict control over its ecosystem, and the clear message that it will replace Objective-C in a near future. According to Apple, “Swift is a powerful and intuitive programming language[…]. Writing Swift code is interactive and fun, the syntax is concise yet expressive.” However, little is known about how Swift developers perceive these benefits. In this paper, we conducted two studies aimed at uncovering the questions and strains that arise from this early adoption. First, we perform a thorough analysis on 59,156 questions asked about Swift on StackOverflow. Second, we interviewed 12 Swift developers to cross-validate the initial results. Our study reveals that developers do seem to find the language easy to understand and adopt, although 17.5% of the questions are about basic elements of the language. Still, there are many questions about problems in the toolset (compiler, Xcode, libraries). Some of our interviewees reinforced these problems.