Summary
In this chapter, we walked through the well-known SOLID principles with simple examples. Sometimes, following those principles could lead us to a useful design pattern. And we also found that those principles are strongly bound to each other. Usually violating one of them may indicate other violations.
Those principles could be extremely helpful for OOD, but could also be overkill if they are applied without proper adaptions. A well-designed system should have those principles confirmed just right, or it might harm.
In the next chapter, instead of theories, we'll have more time with a complete workflow with testing and continuous integration involved.