Today we go over callback functions in Swift and how to use them when working on a background thread. This is a step by step tutorial that will explain what is happening in each line of code so you can grasp the full concept of how callback functions (completion handlers) work, why you would use them, and how to ensure your completion handler is operating on the main thread.
Callbacks are a major part of working with networking tools such as URLSession and Alamofire, but require some understand