Java Collections Framework Part 1 | List, Map, Set, Queue Explained

Описание: Collections are at the heart of real-world Java programming. In this lecture, we’ll explore why Collections are better than arrays, how they work under the hood, and how to use them effectively with code examples.

What you’ll learn in this video (Chapter 12):

Why Collections arrays: resizing, built-in algorithms, safer iteration

Big-O performance in plain English: adds, lookups, iteration costs

Null & ordering policies: how Hash-based vs Tree-based collections behave

Key topics covered:

Enhanced for loop (12.1): simple syntax for iterating lists, sets, and arrays; when not to use it

List: LinkedList (12.2): head/tail operations, when LinkedList beats ArrayList, and common mistakes

Map: HashMap (12.3): key-value model, equals/hashCode contract, iteration patterns, order expectations

Set: HashSet (12.4): enforcing uniqueness, bulk operations, pitfalls with equality and order

Queue interface (12.5): FIFO behavior, method pairs (add/offer, remove/poll, element/peek), and choosing the right implementation

Examples you’ll see:

Iterating Lists vs HashSets to show order differences

Grocery list with LinkedList head/tail adds

Student grades stored in a HashMap

Random unique numbers with HashSet

Ticket line simulation with a Queue