1

Fundamentals

3 modules  ·  all ready ✅
Module 1
📊
Multidimensional Arrays
Chapter 8
🕓 Last updated: Jan 26, 2026
  • 1D Arrays & References
  • 2D and 3D Arrays
  • Ragged (Jagged) Arrays
  • Array of Arrays Concept
Ready →
Module 2
📄
Text I/O
Chapter 12
🕓 Last updated: Jan 27, 2026
  • File Class & Paths
  • Scanner (Reading Files)
  • PrintWriter (Writing Files)
  • Buffers & Flushing
Ready →
Module 3
📝
String
Chapter 10
🕓 Last updated: Jan 31, 2026
  • String Class (Immutable)
  • String Interning
  • StringBuilder & StringBuffer
  • String Methods
Ready →
2

Objects & Classes

2 modules  ·  all ready ✅
Module 4
📦
Objects & Classes
Chapter 9
🕓 Last updated: Feb 19, 2026
  • Intro to OOP — Classes & Objects
  • Constructors & the this Keyword
  • Static Members & Visibility Modifiers
  • Encapsulation, Getters & Setters
  • Arrays of Objects
Ready →
Module 5
💡
Object-Oriented Thinking
Chapter 10
🕓 Last updated: Feb 28, 2026
  • Mutable & Immutable Objects
  • Object Relationships (UML)
  • Dependency, Aggregation, Composition
  • Wrapper Classes & BigInteger
Ready →
3

Inheritance & Polymorphism

2 modules  ·  all ready ✅
▲ Updated Module 6
👪
Inheritance
Chapter 11
🕓 Last updated: Mar 31, 2026
  • Subclass & Superclass
  • super Keyword & Constructor Chain
  • Method Overriding
  • Avoid Redundancy — DRY Principle
Ready →
✦ New Module 7
🔄
Polymorphism
Chapter 11
🕓 Last updated: Apr 13, 2026
  • Polymorphic Variable, Array & Method
  • Static vs Dynamic Binding
  • Upcasting, Downcasting & instanceof
  • ClassCastException & ArrayList
Ready →
4

Advanced OOP

4 modules  ·  3 ready ✅
✦ New Module 8
🛠
Abstract Classes
Chapter 13
🕓 Last updated: Apr 22, 2026
  • Abstract Class vs Abstraction
  • Abstract Methods & Rules
  • The Manager Technique
  • Number Class Case Study
Ready →
✦ New Module 9
🔗
Interfaces
Chapter 13
🕓 Last updated: Apr 25, 2026
  • Diamond Problem & Why Interfaces
  • Interface as a Contract
  • Edible Problem — Full Solution
  • Multiple Interfaces & Payable
Ready →
✦ New Module 10
⚠
Exception Handling
Chapter 12
🕓 Last updated: May 4, 2026
  • Types of Errors & Exception Advantages
  • Exception Hierarchy & Propagation
  • try-catch-finally & throw vs throws
  • Custom Exceptions & Checked vs Unchecked
Ready →
✦ New Module 11
🔬
Generics
Chapter 19
🕓 Last updated: May 9, 2026
  • Why Generics & The Casting Problem
  • Generic Classes, Methods & Interfaces
  • Type Erasure & Compile-Time Safety
Ready →