Understanding SOLID Principles
I was working with a junior developer today based out in India and I mentioned the Single Responsibility principle (SRP)
There was a long pause…. It was clear he had no idea what I was talking about which brings me to the purpose of this post. The SOLID principles.
As a new developer, it's important to understand the SOLID principles as they can greatly improve the maintainability and scalability of your code. The word SOLID is an acronym for five principles of software development: Single Responsibility, Open-Closed, Liskov Substitution, Interface Segregation, and Dependency Inversion. Each principle focuses on a specific aspect of software design and can help to make your code more organized, flexible, and robust.
I’ve described each of the five principles below and highlighted some of their advantages and disadvantages.
Single Responsibility Principle (SRP) The SRP states that a class should have only one reason to change, meaning that a class should have only one responsibility. This principle helps to keep a class focused and makes it easier to understand, test, and maintain.
Advantages:
Easy to understand and test
Changes to one responsibility do not affect other responsibilities
Single responsibility classes can be reused
Disadvantages:
Classes can become too granular
Some responsibilities may require multiple classes
Open-Closed Principle (OCP) The OCP states that a class should be open for extension but closed for modification. This principle helps to ensure that changes to a class do not affect existing code, making the code more robust and less prone to errors.
Advantages:
Changes to a class do not affect existing code
Classes can be extended without modifying the original code
Increases the reliability and maintainability of the code
Disadvantages:
Can make the code more complex
Can lead to unnecessary abstractions
Liskov Substitution Principle (LSP) The LSP states that objects of a superclass should be able to be replaced with objects of a subclass without affecting the correctness of the program. This principle helps to ensure that subclasses are interchangeable with their parent classes.
Advantages:
Increases the flexibility of the code
Makes it easier to add new subclasses
Increases the reliability of the code
Disadvantages:
Can make the code more complex
Can lead to unnecessary abstractions
Interface Segregation Principle (ISP) The ISP states that a class should not be forced to implement interfaces it does not use. This principle helps to keep interfaces small and focused, making them easier to understand and implement.
Advantages:
Increases the flexibility of the code
Makes it easier to add new interfaces
Increases the reliability of the code
Disadvantages:
Can make the code more complex
Can lead to unnecessary abstractions
Dependency Inversion Principle (DIP) The DIP states that a class should not depend on concrete classes but rather on abstractions. This principle helps to decouple classes, making the code more flexible and easier to test and maintain.
Advantages:
Increases the flexibility of the code
Makes it easier to test and maintain the code
Increases the reliability of the code
Disadvantages:
Can make the code more complex
Can lead to unnecessary abstractions
So the SOLID principles are a set of guidelines for writing maintainable and scalable software. As a new developer, it's important to understand these principles and their advantages and disadvantages, so that you can make informed decisions about the design of your code.
By following these principles, you can improve the quality of your code and make it easier to understand, test, and maintain.
They are also highly likely so come up in interview questions too so maybe bookmark this page for reference.