What are the differences between a Dictionary and a List in C#?

What are the differences between a Dictionary and a List in C#?

In C#, a List is an ordered collection of elements, while a Dictionary is a collection of key-value pairs. Lists allow duplicate entries, whereas Dictionaries do not.

Can you give me an example of when to use a Dictionary instead of a List?

Sure! Use a Dictionary when you need to quickly look up values by a unique key, like storing user information by user ID. A List is better for maintaining order and accessing elements by index.

What are the performance implications of using one over the other?

Dictionaries generally offer faster lookups (O(1) on average) compared to Lists (O(n) for searching). However, Lists can be more efficient for iterating through elements.

Are there any scenarios where a List would be preferred over a Dictionary?

Yes, if you need to maintain the order of elements or allow duplicates, a List is the better choice. It's also simpler for scenarios where you just need to store a collection of items.