Overview of C# Collections

C# Collections are data structures that allow you to store and manage groups of related objects. Unlike arrays, collections offer more efficient ways to work with multiple items. This guide covers the primary types of collections in C# and their key features.

Key Concepts

• Collections: A collection is a data structure that holds multiple items.
• Generic vs Non-Generic: Collections can be generic (strongly typed) or non-generic (weakly typed).
• Performance: Different collections exhibit varying performance characteristics, making some more suitable for specific tasks than others.

Types of Collections

1. Array

• A fixed-size collection of items of the same type.
• Example:

int[] numbers = {1, 2, 3, 4, 5};

2. List

• A generic collection that can dynamically grow and shrink in size.
• Allows adding, removing, and accessing items.
• Example:

List<string> fruits = new List<string>();
fruits.Add("Apple");
fruits.Add("Banana");

3. Dictionary

• A collection of key-value pairs.
• Facilitates fast lookups by key.
• Example:

Dictionary<string, int> ages = new Dictionary<string, int>();
ages["Alice"] = 25;
ages["Bob"] = 30;

4. Queue

• A collection that follows the First In, First Out (FIFO) principle.
• Items are added to the end and removed from the front.
• Example:

Queue<string> queue = new Queue<string>();
queue.Enqueue("First");
queue.Enqueue("Second");

5. Stack

• A collection that follows the Last In, First Out (LIFO) principle.
• Items are added and removed from the top.
• Example:

Stack<string> stack = new Stack<string>();
stack.Push("First");
stack.Push("Second");

Conclusion

C# Collections are essential for effectively managing groups of items. By understanding the different types and their use cases, you can choose the appropriate collection for your programming needs. Each collection type features unique capabilities that render it suitable for various scenarios, from storing simple lists to handling complex data relationships.