Java is a mature, portable, object-oriented language used in banking, Android, and enterprise platforms. A top skill in South African ICT.
Start with Lesson 1Each lesson includes a full explanation, code examples, a practice task, common mistakes, and a mini quiz.
Java is a mature, portable, object-oriented language used in banking, Android, and enterprise platforms....
Lesson 1Before writing Java you need the JDK installed and a comfortable editor....
Lesson 2Java's syntax enforces curly braces, semicolons, and case-sensitivity....
Lesson 3Variables store data. Every Java variable has a declared type....
Lesson 4Java is strongly typed — every variable has a compile-time type....
Lesson 5Operators calculate, compare, and combine values....
Lesson 6Conditionals let your program choose different paths based on data....
Lesson 7Loops repeat code until a condition changes....
Lesson 8Arrays store a fixed number of same-type values....
Lesson 9Methods are reusable named blocks of code....
Lesson 10A class is a blueprint; an object is an instance of it....
Lesson 11Constructors initialise objects cleanly in one step....
Lesson 12Private fields + validated access methods = reliable, maintainable code....
Lesson 13A subclass reuses fields and methods from a superclass via extends....
Lesson 14Polymorphism lets different subclasses respond differently to the same method call....
Lesson 15Abstract classes define templates with shared logic and abstract methods subclasses must implement....
Lesson 16Interfaces define contracts — lists of methods a class must provide....
Lesson 17Handle errors gracefully instead of crashing....
Lesson 18Java's Collections Framework provides dynamic lists, sets, and maps....
Lesson 19Read and write files safely using try-with-resources....
Lesson 20JDBC connects Java to relational databases using a consistent API....
Lesson 21