Naming Practices in Object-oriented Programming: An Empirical Study

Abstract

Currently, research indicates that comprehending code takes up far more developer time than writing code. Given that most modern programming languages place little to no limitations on identifier names, and so developers are allowed to choose identifier names at their own discretion, one key aspect of code comprehension is the naming of identifiers. Research in naming identifiers shows that informative names are crucial to improving the readability and maintainability of programs: essentially, intention-revealing names make code easier to understand and act as a basic form of documentation. Poorly named identifiers tend to hurt the comprehensibility and maintainability of software systems. However, most computer science curricula emphasize programming concepts and language syntax over naming guidelines and conventions. Consequently, programmers lack knowledge about naming practices. This article is an extension of our previous study on naming practices. Previously, we set out to explore naming practices of Java programmers. To this end, we analyzed 1,421,607 identifier names (i.e., attributes, parameters, and variables names) from 40 open-source Java projects and categorized these names into eight naming practices. As a follow-up study to further investigate naming practices, we examined 40 open-source C++ projects and categorized 1,181,774 identifier names according to the previously mentioned eight naming practices. We examined the occurrence and prevalence of these categories across C++ and Java projects and our results also highlight in which contexts identifiers following each naming practice tend to appear more regularly. Finally, we also conducted an online survey questionnaire with 52 software developers to gain insight from the industry. All in all, we believe the results based on the analysis of 2,603,381 identifier names can be helpful to enhance programmers’ awareness and contribute to improving educational materials and code review methods.