Unity Quickies - advanced callbacks / listeners on buttons via code

02:09 - the actual code you want, go here for the 20 seconds of useful info.
As quickly as possible I'm going to try to explain how you can use code to attach more versatile logic to button listeners and why it's useful.
Basically you can cast any method to a button's AddListener method with a lambda expression. That's the trick that's all you need to know.