Saying

DRY (Don't Repeat Yourself)

Each piece of knowledge in the system should live in one place.

How to use it. Apply it to meaning. Two functions that look the same but do different things are not duplicates.

How it gets misused. Combining things too early. Wait until you have seen the same thing three times before pulling it together. In tests, repetition is often clearer than cleverness.

Principle Beck's Four Rules of Simple Design A simple design passes its tests, makes intent clear, has no duplicated knowledge, and uses the fewest elements possible. The rules apply in that order.

Clusters

The Code Design cluster - How to write code that survives change.

DRY (Don't Repeat Yourself)

Related

Clusters