Everything You Need to Know About Dependency Injection in Programming
Dependency injection in programming is one of the more talked about terms online, but it’s also one of the most misunderstood. What exactly is dependency injection? How does it relate to programming? How can you implement it? If you’re not exactly sure what dependency injection means, don’t worry — you aren’t alone! Luckily, we’ve got all the answers to your most pressing questions about dependency injection below.
Introduction
Dependency injection is a programming pattern that allows us to remove hard-coded dependencies and make our code cleaner, more flexible, and easier to maintain. With dependency injection, we can easily change how an object gets its dependencies. Instead of having some objects hard-coded with their dependencies (i.e., database connection strings), those dependencies are passed into an object via another object that serves as a container for these ‘dotted’ variables. When using dependency injection within our application, we are able to swap out objects (or create new ones) much easier than if we had hard-coded all of our database connections throughout our application source code. For example, let’s say you have an email service class named EmailService. If you were to use dependency injection within your application, you would not hard-code your SMTP server address inside of EmailService.
