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IT234 Object Oriented Programming with Java

Object Oriented Programming with Java notes

14 chapter notes, in syllabus order. Each starts with the key points.

Unit 1 · 6 hrs

Java Basics: Syntax, Structure & First ProgramUnit 1 of Object Oriented Programming with Java covers Java’s history, setup, basic syntax, data types, variables, operators, control structures, and writing your first program—essential foundations for all OOP concepts.10 min read

Unit 2 · 8 hrs

OOP Concepts: Encapsulation, Inheritance, Polymorphism & AbstractionUnit 2 of Object Oriented Programming with Java covers the four pillars of OOP—encapsulation, inheritance, polymorphism, and abstraction—explaining their definitions, syntax, real-world applications, and how they differ through visual comparisons, code examples, and exam-focused traces.13 min read

Unit 3 · 6 hrs

Classes, Objects, Constructors & Member Access in JavaUnit 3 of Object Oriented Programming with Java covers how to define classes, instantiate objects, use constructors (default/no-arg, parameterized), and control member access via modifiers (private, protected, public). It explains the lifecycle of objects, memory allocation, and how to model real-world entities in code11 min read

Unit 4 · 6 hrs

Inheritance, Method Overriding & Polymorphism in JavaUnit 4 of Object Oriented Programming with Java covers inheritance hierarchies, method overriding rules, runtime polymorphism, and the super keyword, with real-world examples from Nepalese apps like eSewa and Ncell, plus code traces and comparison tables.6 min read

Unit 5 · 6 hrs

Interfaces, Abstract Classes & Polymorphism in JavaUnit 5 of Object Oriented Programming with Java covers interfaces (contracts, multiple inheritance, default/static methods), abstract classes (partial implementation, abstract methods), and their real-world applications in designing flexible, reusable code. Learn how to use them to enforce structure, achieve polymorphi11 min read

Unit 6 · 6 hrs

Exception Handling: Try-Catch, Throw, Custom Exceptions, and Best PracticesUnit 6 of Object Oriented Programming with Java covers exception handling mechanisms, including checked vs. unchecked exceptions, try-catch-finally blocks, throw and throws, custom exceptions, and best practices for robust error handling in Java applications.9 min read

Unit 7 · 6 hrs

File I/O in Java: Streams, Files, and SerializationUnit 7 of Object Oriented Programming with Java covers file handling techniques in Java, including stream types (byte/character), file operations (read/write), serialization, and best practices for robust I/O handling with error management.14 min read

Unit 8 · 6 hrs

Strings, Wrapper Classes & Java Type ConversionUnit 8 of Object Oriented Programming with Java covers string manipulation (methods, immutability, regex), wrapper classes (autoboxing, unboxing), and type conversion (casting, parsing, and instanceof). Learn how to handle text data, convert primitives to objects, and avoid common pitfalls in Java I/O and data processi15 min read

Unit 9 · 4 hrs

Collections, Generics & Java’s Data StructuresUnit 9 of Object Oriented Programming with Java covers Java’s Collections Framework (List, Set, Map, Queue), Generics for type-safe containers, and real-world data structures (ArrayList, LinkedList, HashMap, TreeSet) with implementation details, time/space complexity, and practical examples from Nepali apps like eSewa 19 min read

Unit 10 · 4 hrs

Packages, Access Modifiers & Java EncapsulationUnit 10 of Object Oriented Programming with Java covers how to organize code into packages, control access to classes/methods using modifiers (public, private, protected, default), and enforce encapsulation—key concepts for modular, secure Java programs.11 min read

Unit 11 · 6 hrs

Polymorphism, Abstraction, Sealed Classes & Design PatternsUnit 11 of Object Oriented Programming with Java explores polymorphism (compile-time vs. runtime), abstraction (interfaces vs. abstract classes), sealed hierarchies, and design patterns (Singleton, Factory, Observer) with real-world Java examples and implementation traces.9 min read

Unit 12 · 4 hrs

Java Utilities, Scanner, and System ClassesUnit 12 of Object Oriented Programming with Java covers the java.util package, Scanner class for input handling, and utility classes like Math, Random, and System. Learn how to read user input, generate random numbers, format output, and use built-in utilities for efficient programming.13 min read

Unit 13 · 4 hrs

Type Conversion & Casting: Implicit, Explicit, and Object CastingUnit 13 of Object Oriented Programming with Java covers type conversion (primitive and object), casting rules, widening/narrowing conversions, and their applications in real-world Java programs, with visual traces of how values change during operations.9 min read

Unit 14 · 4 hrs

Character Handling, Sealed Classes & Java Text ProcessingUnit 14 of Object Oriented Programming with Java covers Unicode character encoding, Java’s char type, text manipulation methods, and sealed classes—including their syntax, restrictions, and use cases in secure hierarchies.7 min read