Start Learning
Javaneer
Back to roadmap
🏗️
Stage 2

Object-Oriented Programming

Model the real world in code.

Classes and objects, the four pillars of OOP, interfaces and abstract classes, modern types, and correct equality - the mental model behind all Java software.

5 Lessons in this stage1 h 30 min
Start the first lesson

Lessons in this stage

  1. 01

    OOP Fundamentals

    Beginner

    Classes and objects, fields, methods, constructors, this, and static - the blueprint-and-house analogy.

    18 min
  2. 02

    The Four Pillars

    Intermediate

    Encapsulation, Inheritance, Polymorphism, and Abstraction - each with a real-life example.

    22 min
  3. 03

    Interfaces & Abstract Classes

    Intermediate

    Contracts versus partial implementations, default methods, and when to use which.

    16 min
  4. 04

    Records, Sealed Classes & Enums

    Intermediate

    The modern Java type system: records, sealed hierarchies, pattern matching, and enums.

    18 min
  5. 05

    Object, Equality & Immutability

    Intermediate

    equals and hashCode done right, toString, and why immutability makes life easier.

    16 min