Java

16 lessons — from the very basics to pro-level patterns.

Basics

0. Why Learn Java?

Banks, Android, and billion-user systems — Java runs them all

1. Variables & Data Types

int, double, String — Java is picky about types

2. Operators & Expressions

Math, comparisons, and logical operators

String methods, StringBuilder, and formatting

4. Conditionals

if/else, switch, and ternary expressions

for, while, do-while, and enhanced for

Collections

Fixed-size boxes — declare, fill, and loop

Functions

Parameters, return values, and overloading

Object-Oriented Programming

8. Classes & Objects

Blueprints, constructors, and this keyword

9. Inheritance & Polymorphism

extends, super, and method overriding

10. Interfaces & Abstract Classes

Contracts that classes must follow

Intermediate

11. Collections Framework

List, Set, Map — the power tools of Java

Type-safe containers that work with anything

13. Exception Handling

try/catch, checked vs unchecked, and throws

Advanced

Reading and writing files with try-with-resources

15. Lambdas & Streams

Functional-style data processing in Java