Getting ready

Before learning how to write generic code, let's see an example of a problem that generics solve. I bet you are familiar with stack data structures and have been using it in one of the computer science courses before. Anyway, it's a kind of collection data structure that follows LIFO (Last in first out). It has very commonly used APIs for these operations, which are pop and push. Push inserts new item to the stack; pop returns the last inserted one. It's just a simple overview, as we will not explain data structures in this book as it's out of topic.