C# Dictionary vs List: What's the Difference?

What are the main 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.

When should I use a Dictionary instead of a List?

You should use a Dictionary when you need to quickly look up values by a unique key. Lists are better for ordered collections where you need to access elements by their index.

Can you give me an example of when to use each?

Sure! Use a List for storing a collection of names where order matters. Use a Dictionary for storing user information where you can access it by user ID.

Are there performance differences between them?

Yes, accessing an element in a List by index is O(1), while accessing a value in a Dictionary by key is also O(1) on average, but inserting and deleting elements can be faster in a Dictionary due to its hash table implementation.