DRY Concepts

Don't repeat yourself (DRY) is a principle of software development aimd at reducing repetition of software patterns, replacing it with abstractions or using data normalization to avoid redundancy.

An example of DRY in a funny format

The DRY Principle is stated as "Every piece of knowledge must have a single, unambiguous, authoritative representation within a system". This principle has been formulated by Andy Hunt and Dave Thomas in their book "The pragmatic programmer". This principle can be applied to any section in programming ad designing such as database schemas, test plans, documentation and the build system.

DRY also includes other concepts and practices such as Abstraction, Code Reuse and Separation of Concerns.

Why is it good?

As stated above, DRY is good in that it saves time and effort, it is easy to maintain, and also reduces the chances of bugs.

Any Disadvantages?

So complying with the DRY principle means you need to Abstract your code whilst coding, sometimes the planning takes longer than actually repeating yourself for a few lines of code, and also code becomes harder to read which is never good, especially for other programmers who may want to debug your code in the future.

Sources: (click on them to see them)