O'Reilly logo
  • Ahmed Elgendy thinks this is interesting:

Design Principle

Identify the aspects of your application that vary and separate them from what stays the same.


The first of many design principles. We’ll spend more time on these throughout the book.

Take what varies and “encapsulate” it so it won’t affect the rest of your code.

The result? Fewer unintended consequences from code changes and more flexibility in yo...


Cover of Head First Design Patterns


First design principle.