How can List<T>.Item Property be O(1)? Typo?

Question

I'm implementing a priority queue and want to iterate through the list to insert at the right spot. In the documentation it states that C# List<T>.Item Property is O(1): List<T>.Item Property

e.g.

int retrivedValue = myIntList[5]; 

How is this possible since add also is O(1)? It's like eating the cookie and still have it. Normal lists in my head have O(n) for accessing an element.

Answer 1

The standard List type is backed by an internal array with O(1) access performance.

List does not use a linked list implementation.