There are lots of “rules” we must follow in object-oriented software development and the article The Genius of the Law of Demeter by Javadevguy summarizes how they are useful. From what I put together, it seems like the Law of Demeter took abstract concepts and basically put them into a universal set of rules for Object-Oriented code.
I thought that the law of demeter must be a big deal if someone decided to sit down and write a lengthy blog post about it. This content ended up being interesting as it tried to convince readers why they should obey this “law.” The Law of Demeter basically paves the way for what users can do to a given method. It is kind of like considering the restrictions or possibilities based on the method. One of the takeaways I got from this is how there is a lot of focus on communication between two objects.
The rules listed in the article are as follows–noting that it says “For all classes C, and for all methods M attached to C, all objects to which M sends a message must be”:
- M’s argument objects
- Instance variable objects of C
- Objects created by M, or by functions or methods which M calls
- Objects in global variables (
staticfields in Java)
Another useful takeaway I got from this article came from observing the code examples Javadevguy included; how Rule #1 covers that any method can be called on the current object. I also noted when there would be an instance where the law would prohibit something is not “sending a message” to any already existing object that is held in instance variables of other classes.
This will affect the way I continue to do work as an Object-Oriented developer. I mean, in life when you learn there is a more useful or structured way to help you achieve more effective results, you would want to try or follow it, right? For my future use, I will acknowledge (like other blogs and articles) that the Law of Demeter is less of a law and only a suggestion or a guideline.
Overall, I would say that the content has helped further solidified my understanding of some Object-Oriented coding concepts. I agree with the content as it is trying to help people become better developers or better understand the Law of Demeter in general.