The Single Responsibility Principle (SRP) is one of the five SOLID principles of object-oriented programming, emphasizing a key aspect of good software design. It states that a class or module should have only one reason to change, meaning it should have only one responsibility or job within the software system.
Principles of SRP:-
One Responsibility:
- A class or module should encapsulate and handle only one specific aspect or functionality within the system.
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Reason to Change:
- If there is more than one reason for a class to change, it violates the SRP. Each class should focus on one aspect that may change independently of the others.
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High Cohesion:
- Classes that follow SRP have high cohesion, meaning all its methods and properties are related to its single responsibility.
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Low Coupling:
- SRP helps in achieving low coupling between classes since each class is focused on its specific task and doesn't have unnecessary dependencies on other unrelated functionalities.
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Maintainability:
- Code becomes easier to maintain as changes are limited to a single responsibility. Modifying one responsibility doesn’t affect others, reducing the risk of unintended consequences.
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Readability and Understandability:
- Classes with single responsibilities tend to be more focused and easier to understand. Developers can quickly comprehend the purpose of a class and its role within the system.
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Reusability:
- Classes with well-defined responsibilities are more likely to be reusable across different parts of the system or in other projects.
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Testing and Debugging:
- Units with single responsibilities are easier to test and debug since the behavior of the class is specific and isolated.
Consider a class User that manages user authentication and also handles user profile information. This violates the SRP as it takes care of both authentication and user profile management. It would be better to split this class into two:
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UserAuthentication:Responsible for handling user login, logout, and authentication-related tasks. -
UserProfile:Responsible for managing user profile information, updates, and related functionalities.
By adhering to SRP, these classes become more focused, easier to maintain, and less prone to changes caused by unrelated functionalities.
Following SRP promotes better code organization, readability, maintainability, and overall software design quality by encouraging a clear separation of concerns and responsibilities within the system.
