SOLID-principles | Code examples of the SOLID principles

SOLID-principles is a C# library. SOLID-principles has no bugs, it has no vulnerabilities, it has a Permissive License and it has low support. You can download it from GitHub.

Code examples of the SOLID principles. A class should take care of a Single Responsibility. This Add method does too much, it shouldnt know how to write to the log and add a customer. Good Way, not violating the single responsibility principle. Now we abstract the logger, so its writing the error. Prefer extension over modification. Violating the Open Closed Principle This is bad, because at the moment, there are 2 types of customer, if we want to add another customer type we have to add a if else below. So Modifying the existing code. This is better, because we structure the code so its easier to extend and hard to modify. Parent class should be able to refer child objects seamlessly during runtime polymorphism. BAD: Violating Liskov substitution principle The parent should easily the replace the child object and not break any functionality, only lose some. e.g. here, we don't want this to add an enquiry so we have to throw a new exception, that is violating the principle. Client should not be forced to use an interface, if it doesn't need it. If we want to add more functionality, don't add to existing interfaces, segregate them out. Just create another interface, that a class can ALSO extend from. High level modules should not depend on low-level modules, but should depend on abstraction. Bad: We are relying on the customer to say that we are using a File Logger, rather than another type of logger, e.g. EmailLogger. Good: We pass in a Logger interface to the customer so it doesnt know what type of logger it is.