Don't Repeat Yourself (DRY)

May 06, 2024#cs#principles

The Don’t Repeat Yourself (DRY) principle is a fundamental concept in software development that aims to reduce repetition in code and other aspects of a system. It is based on the idea that repetition in code or other parts of a system can lead to inefficiencies, errors, and increased maintenance costs.

The principle is often summarized as “every piece of knowledge must have a single, unambiguous, authoritative representation within a system”.

The DRY principle is primarily concerned with eliminating duplication in two areas:

  • Logic Duplication: This refers to the repetition of similar code or logic in different parts of a system. The principle suggests that such duplication should be eliminated by abstracting the logic into a single, reusable piece of code. This approach helps to reduce the complexity of the system, making it easier to understand, modify, and extend.

  • Process Duplication: This involves the repetition of processes or tasks within a system. The DRY principle recommends eliminating such duplication by automating processes wherever possible. This approach helps to reduce the workload and the potential for errors associated with manual processes.

The DRY principle is closely related to other software development principles, such as the Single Responsibility Principle (SRP), the Open-Closed Principle (OCP), and the Single Source of Truth (SSOT/SPOT). These principles all contribute to the overall goal of creating software that is maintainable, scalable, and easy to understand.

In summary, the DRY principle is a key concept in software development that emphasizes the importance of reducing repetition in code and processes to create more efficient, maintainable, and scalable systems.