Single Responsibility

Single Responsibility Principle (SRP)

Brief Overview of the Principle

The Single Responsibility Principle (SRP) states that a class should have only one reason to change, meaning it should have only one job or responsibility. This principle is focused on ensuring that a class or module is only tasked with a single concern or functionality, making the system easier to maintain and understand.

Why It’s Important

• Maintainability: When a class has a single responsibility, it is easier to understand, maintain, and modify without affecting other parts of the system.
• Reusability: Classes with well-defined responsibilities are more reusable across different parts of the application or even different projects.
• Testability: Smaller, single-purpose classes are easier to test because they have fewer dependencies and simpler behaviors.

Common Misconceptions

• Single Responsibility Means Single Method: SRP does not imply that a class should only have one method. A class can have multiple methods as long as they all contribute to a single responsibility.
• One Class Per File: SRP does not dictate that each class must be in its own file, though this can sometimes help with organization. The principle is about responsibility, not file structure.
• Responsibility Equals Functionality: Responsibility refers to a reason to change. A class can have multiple functionalities as long as they all relate to a single responsibility or cause for change.