Mastering the Art of Software Design: A Deep Dive into SOLID Principles
Tags: solidprinciples, javascript, programming, webdev
Published: 2023-10-12 10:39:12

If you are coming after reading previous article titled as [Mastering the Art of Software Design: Unveiling the Core Principles](https://dev.to/dr_anks/mastering-the-art-of-software-design-unveiling-the-core-principles-1ag3), I have already briefed about SOLID principles, You don't wanna go, I will write for you too. Let's jump into.

Writing maintainable, scalable, and reliable code is essential in the constantly changing world of software development. The SOLID principles are one set of design principles that software developers have developed over the years to accomplish this. Robert C. Martin's five guiding principles serve as a guide for creating readable, flexible, and maintainable software code. We will go into each SOLID principle in this blog article, examining what it implies and how it may be used to improve software design.

SOLID is an acronym of 5
1. Single Responsibility Principle (SRP)
2. Open/Closed Principle (OCP)
3. Liskov Substitution Principle (LSP)
4. Interface Segregation Principle (ISP)
5. Dependency Inversion Principle (DIP)

## 1. Single Responsibility Principle (SRP)
According to the single responsibility principle, a class should only have one cause for change. In other words, each class should be assigned only a single task. Maintaining, testing, and extending a class is more difficult when it has several duties. You may make your code more modular and understandable by following SRP.

It is preferable to divide a class that receives data from a file and conducts calculations into two independent classes—one for reading the data and the other for executing the computations—if you are designing such a class. In this manner, the computation logic won't be affected if you need to change how data is read.

## 2. Open/Closed Principle (OCP)
The Open/Closed Principle promotes openness for extension but closure for modification in software entities (classes, modules, and functions). In essence, it implies that you ought to be able to expand your code to include new features or behaviors without having to change the present codebase. This rule reduces the possibility of adding problems to previously functional code and encourages code reuse.

You can create adaptable and extensible systems by using methods like inheritance, interfaces, and abstract classes that comply to OCP. Instead of directly altering existing classes or modules in response to changing requirements, you can construct new classes or modules that extend them.

## 3. Liskov Substitution Principle (LSP)
According to the Liskov Substitution Principle, objects of a derived class must be interchangeable with those of the base class without impairing the program's ability to run correctly. To put it another way, it guarantees that derived classes can be used interchangeably with their base classes without leading to unexpected behavior.

Class hierarchies must be properly designed in order to achieve LSP compliance and must not violate the agreements made by base classes or interfaces. Small bugs and maintenance issues may result from violations of this principle.

## 4. Interface Segregation Principle (ISP)
The Interface Segregation Principle recommends against making clients rely on interfaces they do not use. In other words, it encourages the development of narrow, focused interfaces as opposed to broad, unified ones. Classes that implement interfaces need only supply implementations for the methods pertinent to their particular functionality in this fashion.

By adhering to ISP, you can avoid the "fat interfaces" issue, which occurs when classes are overloaded with methods they don't need to implement, resulting in code bloat and possible SRP breaches.

## 5. Dependency Inversion Principle (DIP)
High-level modules are encouraged not to depend on low-level modules by the Dependency Inversion Principle. They ought to both rely on abstractions. Additionally, it implies that abstractions should rely on details rather than the other way around.

DIP encourages loose connectivity between modules, which makes it simpler to upgrade or replace parts without harming the system as a whole. In actuality, this entails defining dependencies via interfaces or abstract classes, enabling dependency injection and inversion of control (IoC) containers.

## Conclusion
The SOLID principles provide a framework for creating well-structured, maintainable, and extensible software designs. While applying these principles may necessitate additional effort and planning in the beginning, the long-term benefits in terms of code quality, flexibility, and simplicity of maintenance are well worth it. Software developers may create systems that stand the test of time and adapt to changing requirements by using SRP, OCP, LSP, ISP, and DIP. Understanding and using these principles is a crucial skill for any software developer who strives to build clean and efficient code.