Skip to main content

Understanding the SOLID principles


On today’s blog we are going to talk about the SOLID principles, which were discovered by Robert Martin, the famous Uncle Bob from the podcast of the previous entry. This principles are recommended to be used whenever someone wants to create an object oriented program. There are 5 principles where the acronym SOLID comes from which are the following
  • Single Responsibility Principle (SRP) -> it says that any class should only have one responsibility. Yet, the author ends up saying that there might be some classes that have two responsibilities (the invoicing class that has some logging routines). In the end, I didn’t understand this principle well because I found the explanation confusing (as the author said, practice is much more difficult than theory). 

  • Open/Closed Principle (OPC) -> open extension but closed modification Although the author says that if you change a parent class method it might kill another part of the code, I think that this would only reflect your lack of knowledge of your own code, and we should have the capacity of modifying our own code.

  • Liskov Substitution Principle (LSP) -> avoiding inheritance, as we have seen before, is actually a really useful advice. I think that we should try to use composition as much as we can.

  •  Interface Segregation Principle (ISP) -> I had never heard about this principle before, which describes that instead of having a huge interface that has many different methods, we should create a bunch of small interfaces. I find this principle pretty useful, because it is easier to refactor a small and well-organized code.

  • Dependency Inversion Principle (DIP) -> this last principle says that we should code base on abstractions, rather than coding based on concrete objects. I think this is also a great advice. If we code thinking that our objects might changes, and that they should look like this, instead of being like this, it would be easier to modify them and to adapt the future.

Comments

Post a Comment

Popular posts from this blog

Hidden Figures

On today’s blog I’m going to talk about a movie called Hidden Figures, directed by Theodore Melfi and released in 2016. I watch this movie during my class of software design and architecture and I have to admit it, I liked it, but not that quite much, is the kind of movie that you could see in a Sunday morning on tv, at least for me. The movie talks about three women and how they helped the NASA during the space race to make during the cold war (I think it was during the cold war) against the Russians. In the movie there are introduced three women, Katherine Goble, Mary Jackson and Dorothy Vaughn, who are trying to contribute and make their own way through their jobs in NASA. More importantly the movie shows how they struggle because of the discrimination at the time, so they couldn’t receive the treat they deserved, all of this happened during the NASA project of the first man to the moon. For many of us, we can´t imagine that kind of discrimination, but in the movie,   it
Post a Comment
Read more

Microservices

On today’s blog entry we are going to talk about the Microservices architecture. This architecture has an approach where when we are developing a single app, we develop it as lots of small services, each of them running on its own process and communicating with each other with something that can bind them together. Now I have already used microservices without knowing I was actually using them, perhaps this architecture is quite intuitive for best practices or something like that, but anyway the author of the article gives some characteristics about this which are the following: ·          Componentization via Services: The components of the microservice need to be gather into libraries that will be used later on by the microservice to communicate with remote parts of the whole program. ·          Organized around Business Capabilities: This characteristic refers that we need to create divisions, each of the divisions need to be focused on the business capability which includ
Post a Comment
Read more

War Games

On today’s blog I’m going to talk about a movie released in 1983, War Games, which has been directed by John Badham. The movie shows the story of David Lightman, a kid who is kin of a genius in topics of computer science, the plots consists of how this kid started to hack to the system of the US military by accident because he thought he was hacking a videogame company instead, when he hacks the system he discovers a simulation created by the military called Thermonuclear War, now, Lightman thinks is a game so he stars to play it, the “game” consist on two sides or teams, the USSR or the United States, and after choosing sides, the teams decides where to launch a nuclear bomb, all of this is situated during the Cold war so the simulation has   that theme; the problem starts when the simulation actually prepares to launch real bombs and Lightman gets caught by the government because of the hacking, then when they explain the situation to him he finds the creator of the simulatio
Post a Comment
Read more