Design patterns are important for developers to use in their code. They make your programs easy to read and implement and they are able to be adapted to many situations. There are 3 kinds of design patterns: creational, structural, and behavioral.
Creational patterns are used for creating objects. They give flexibility to change the creation process and allow for many types of objects to be created using the same method. The singleton pattern is used when there should only be one instance of an object. Instead of creating a new object every time you need to call it, you call a method that will call an instance of the object. The builder pattern is used when an object has a lot of optional parameters that make it difficult to know what is being applied when it is created. Using a builder pattern creates an empty or default object and then calls set methods to add each parameter you want to use. The factory pattern is for when there are a lot of objects of a certain type, but with different forms. Instead of creating many new objects, you call a factory to create the objects with the specifications hidden in the factory code.
Structural patterns are used for how objects relate to each other. These patterns allow for high level code to be readable and simple, while keeping the intricacies hidden below the surface. The facade pattern is used when there are many operations and calculations behind the scenes of a process and those are all hidden with encapsulation. On a high level, one method will, for example, purchase a product, but deeper, there is a payment being processed, shipping calculations, inventory checks, etc. The adapter pattern is for when a program needs to be adapted to fit your code. It can be used for implementing public libraries where their units do not match what your program expects, and each time you use the public library, it calls the adapter to modify the output.
Behavioral patterns are used for how objects interact with each other. The strategy pattern is used when you have multiple ways of doing a process. Instead of using a lot of if else statements, you can define several strategies and set each object to have a strategy. The observer pattern is used for objects that watch for something. It works by “subscribing” to receive a notification of an event. If a program is watching for errors, it would be automatically notified of any errors so it can add it to a log.
In class, we went over the strategy, factory, and singleton patterns for the Duck example. These 7 patterns are common practice in the software development field and it’s important to know how to implement them. I watched a video explaining these patterns and now I have a deeper understanding of the three we learned and the four that were new to me. I feel confident I can expand on these in a professional setting.
From the blog ALIDA NORDQUIST by alidanordquist and used with permission of the author. All other rights reserved by the author.
Hey guys, it’s a weird feeling to be wrapping up my last semester in my undergraduate career in computer science (and sociology). For this final installment of my AMPATH sprint series, I will just go over the general overview of what went on for my team.
In this final installment of my individual apprenticeship patterns, I think an important one to write about would be Find Mentors. To summarize the main point of this one, I would say that it encourages people to observe their role and their surroundings to see where they can find the most value from learning or use their resources. It encourages you to look at things from one level back instead of blindly jumping into something right away.