Don’t Repeat Yourself

最新推荐文章于 2024-12-11 07:51:26 发布

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最新推荐文章于 2024-12-11 07:51:26 发布

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原文链接：http://www.cnblogs.com/luchuanbing/p/7920417.html

DRY原则强调通过抽象消除逻辑重复，并通过自动化消除过程重复。本文深入探讨了如何使用设计模式来重构条件语句，减少代码中的冗余，提高软件质量。

The Don’t Repeat Yourself (DRY) principle states that duplication in logic should be eliminated via abstraction; duplication in process should be eliminated via automation.
Duplication is Waste
Adding additional, unnecessary code to a codebase increases the amount of work required to extend and maintain the software in the future.

Duplicate code adds to technical debt. Whether the duplication stems from Copy Paste Programming or poor understanding of how to apply abstraction, it decreases the quality of the code.

Duplication in process is also waste if it can be automated. Manual testing, manual build and integration processes, etc. should all be eliminated whenever possible through the use of automation.

Suspect Conditionals

Often, if-then and switch statements have a habit of being duplicated in multiple places within an application.

It’s common in secured applications to have different functionality available to users in certain roles, so the code may be littered with if-user-is-in-role checks.

Other applications may have been extended to deal with several similar but distinct kinds of data structures, with switch() statements at all levels of the workflow used to describe the differences in behavior each data structure should have.

Wherever possible, refactor these conditionals using well-known design patterns to abstract the duplication into a single location within the codebase.