Kevin Schroeder is continuing his current trend of posts with another new one about Magento 2 and using deendency injection and how to use it inside your Magento extension code.

I wrote an introduction to Dependency Injection for Zend Framework a while back and was able to work out some of the kinks in my understanding of how a DI container worked with 4 blog posts. It took a while for me to get it but much of what I learned for Zend Framework does directly apply for Magento 2. Dependency Injection is handled in Magento 2 via the class MagentoAppObjectManager. And if you look at that from within the context of Magento 2 you are probably pooping your pants. 200+ class instances, configuration options, dogs and cats living together.

He starts with a simple script that calls the DI container to get an instance of a "Test" class. He talks about the difference between this and calling "new" and gives a bit more complex example with a custom "Test2" class. It's only slightly more complex as he shows how an instance of "Test2" with a property of a "Test" instance gets created and built out and injected into the "Test2" class on initialization.