C# gives you powerful built-in collections to store groups of data.
📋 List
A resizable list of items.
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List<string> names = new List<string>();
names.Add("Alice");
names.Add("Bob");
Console.WriteLine(names[0]); // Alice
📖 Dictionary<TKey, TValue>
Pairs of keys and values.
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Dictionary<string, int> ages = new Dictionary<string, int>();
ages["Alice"] = 30;
ages["Bob"] = 25;
Console.WriteLine(ages["Bob"]); // 25
📦 Queue
First-in, first-out (FIFO).
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Queue<string> queue = new Queue<string>();
queue.Enqueue("first");
queue.Enqueue("second");
Console.WriteLine(queue.Dequeue()); // first
🗄️ Stack
Last-in, first-out (LIFO).
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Stack<int> stack = new Stack<int>();
stack.Push(1);
stack.Push(2);
Console.WriteLine(stack.Pop()); // 2
💡 When to Use Each?
- List: Simple list of items, access by index.
- Dictionary: Lookup by key.
- Queue: Process items in the order added.
- Stack: Process items in reverse order.
Next: Declaring and using generic methods and classes!
