We have reached our final destination in our overview of the five SOLID design principles! The final principle is the Dependency Inversion principle, and it states that high-level code should not depend on low-level code. Instead, high-level code should depend on an abstraction layer that serves as a "middle-man" between the high and low-level code. A second aspect to the principle is that abstractions should not depend upon details, but rather details should depend upon abstractions. If this all sounds extremely confused, don't worry. We'll cover both aspects of this principle below.
Dependency Inversion Principle 依赖反转原则
This principle states that high-level code should not depend on low-level code, and that abstractions should not depend upon details.