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

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

In C#, List, Array, and Dictionary are all collection types but serve different purposes. An Array is a fixed-size collection of elements of the same type, while a List is a dynamic collection that can grow or shrink in size. A Dictionary, on the other hand, stores key-value pairs, allowing for fast lookups by key.

Can you give me examples of when to use each type?

Sure! Use an Array when you know the number of elements in advance and need fast access. Use a List when you need a resizable collection, like when adding or removing items frequently. Use a Dictionary when you need to associate unique keys with values, like storing user IDs with user information.

What are the performance implications of using each collection?

Arrays have the best performance for fixed-size collections due to their contiguous memory allocation. Lists have slightly more overhead due to resizing but are still efficient for most use cases. Dictionaries offer fast lookups but can be slower for insertion and deletion due to hashing.

Are there any other collection types I should know about?

Yes, there are several other collection types in C#, such as HashSet for unique items, Queue for FIFO operations, and Stack for LIFO operations. Each has its own use cases depending on your needs.