Interface Segregation in Practice
Apply the Interface Segregation Principle to create lean, specific interfaces, avoiding fat interfaces that force clients to depend on methods they don't use.
What is ISP?
Welcome to the Interface Segregation Principle (ISP)! This principle is one of the five SOLID principles of object-oriented design.
At its core, ISP states that clients should not be forced to depend on interfaces they do not use. In simpler terms, don't make classes implement methods they don't need.
The Problem: Fat Interfaces
A 'fat interface' is an interface that contains too many methods, some of which are irrelevant to certain classes that implement it.
When a class implements a fat interface, it's forced to provide implementations for all methods, even those it doesn't use. This often leads to empty or placeholder method bodies, which is a code smell.
All lessons in this course
- Deep Dive into Dependency Inversion
- Interface Segregation in Practice
- Refactoring with Design Patterns
- Single Responsibility and Open-Closed Mastery