Why would one use Stack<T> instead of List<T>? [closed]

Question

List<T> from System.Collections.Generic does everything Stack<T> does, and more -- they're based on the same underlying data structure. Under what conditions is it correct to choose Stack<T> instead?

Answer 1

You would use stack if you had a need for a Last In First Out collection of items. A list will allow you to access it's items at any index. There are a lot of other differences but I would say this is the most fundamental.

Update after your comment:

I would say that using Stack<T> makes a statement about how you want this code to be used. It's always good to plan for the future, but if you have a need for Stack<T> right now, and no compelling reason to use List<T> then I would go with Stack<T>

Answer 2

why I would artificially limit myself to using Stack in new code

There's your answer - you should use Stack when you have a need to enforce a contractual expectation that the data structure being used can only be operated on as a stack. Of course, the times you really want to do that are limited, but it's an important tool when appropriate.

For example, supposed the data being worked with doesn't make any sense unless the stack order is enforced. In those cases, you'd be opening yourself up to trouble if you made the data available as a list. By using a Stack (or a Queue, or any other order-sensitive structure) you can specify in your code exactly how the data is supposed to be used.