Java Course

Java has been the backbone of enterprise software, Android apps, and countless backend systems for three decades. It's a statically typed, object-oriented language that trades brevity for precision — the compiler catches whole categories of mistakes before your program ever runs. This course takes you from a bare Hello, Java! up through classes, inheritance, and the collection types you'll actually reach for in real code.

What you'll learn

The first half covers the fundamentals every Java program is built from: variables, operators, strings, conditionals, and loops. The second half moves into object-oriented programming — the part of Java that shapes how larger programs get organized: arrays, methods, classes and objects, constructors, inheritance, and the ArrayList/HashMap collection types that replace fixed-size arrays in most real-world code. Every lesson traces hand-written examples all the way through to their exact console output, since Java doesn't run live in a browser the way HTML or JavaScript can.

Lessons

  1. Introduction
  2. Variables & Data Types
  3. Operators
  4. Strings
  5. Conditionals
  6. Loops
  7. Arrays
  8. Methods
  9. Classes & Objects
  10. Constructors & this
  11. Inheritance
  12. ArrayList & Collections
Where to start: begin at Introduction and work through in order — later lessons lean on earlier ones without re-explaining them. If you've already written Java before and just need a refresher on object-oriented syntax, lessons 09 through 12 (Classes & Objects through ArrayList & Collections) stand reasonably well on their own.