"High-level modules should not depend on low-level modules, but rather both should depend on abstractions."
The Dependency Inversion Principle (DIP) is a design principle in computer science, introduced by Robert Martin as part of the SOLID principles of software design. It states that high-level modules should not depend on low-level modules, but rather both should depend on abstractions.
In other words, the DIP is a principle of object-oriented programming, which states that the design of a system should be decoupled from the specific implementations of its components. This helps to reduce the coupling between objects and makes the code easier to maintain and modify.
The DIP is achieved by defining a clear set of abstractions, such as interfaces or abstract classes, that can be used to define the behavior of objects. These abstractions are then used to define the relationships between objects, rather than relying on the concrete implementations of the objects.
For example, instead of creating a concrete class that defines the behavior of a particular object, it is better to create an interface that defines the behavior, and then have the concrete class implement the interface. This way, the concrete class can be swapped out for another implementation without affecting the rest of the system.
To follow the DIP, it is important to define abstractions that define the behavior of objects, and to use those abstractions to define the relationships between objects. This helps to reduce the coupling between objects and makes the code easier to maintain and modify.
In summary, the Dependency Inversion Principle is a design pattern that helps to reduce coupling between objects, by ensuring that high-level modules do not depend on low-level modules, but rather both depend on abstractions. This makes the code easier to understand, test, and modify, and improves the overall quality of the code.