Course contents

Module 01

Java Fundamentals

Start here. How Java runs, its type system, control flow, methods and arrays: the base every later module builds on.

Free module6 topics26 lessons & question sets26 ready

By the end of this module you can

  • Explain exactly how a .java file becomes a running program
  • Use primitives, wrappers and casting without surprises
  • Reason about pass-by-value and method calls

How Java runs

JDK, JRE and JVM, and the journey from source code to a running program.

  1. JDK, JRE and JVM explainedLesson · 11 minFree
  2. From source to bytecode to running programLesson · 11 minFree
  3. Your first Java program and the main() methodLesson · 10 minFree
  4. How Java runs: interview questions & scenariosInterview Q&AFree

Data types & variables

Primitives, wrappers, casting and the defaults that trip people up.

  1. Primitive types and their sizesLesson · 12 minFree
  2. Wrapper classes and autoboxingLesson · 11 minFree
  3. Type casting and numeric promotionLesson · 11 minFree
  4. Default values, literals and constantsLesson · 10 minFree
  5. var and local type inferenceLesson · 10 minFree
  6. Data types & variables: interview questions & scenariosInterview Q&AFree

Operators & control flow

Operators, precedence, branching and loops.

  1. Operators and precedenceLesson · 10 minFree
  2. if, switch and the switch expressionLesson · 10 minFree
  3. Loops, for-each, break, continue and labelsLesson · 9 minFree
  4. Operators & control flow: interview questions & scenariosInterview Q&AFree

Methods & arrays

How method calls really pass arguments, overloading, varargs and arrays.

  1. Methods and why Java is always pass-by-valueLesson · 11 minFree
  2. Overloading and varargsLesson · 11 minFree
  3. Arrays and multi-dimensional arraysLesson · 10 minFree
  4. Methods & arrays: interview questions & scenariosInterview Q&AFree

Strings basics

The String API you use every day and comparing strings correctly.

  1. Essential String methodsLesson · 12 minFree
  2. == vs equals() for stringsLesson · 10 minFree
  3. Reading input and formatting outputLesson · 11 minFree
  4. Strings basics: interview questions & scenariosInterview Q&AFree

Packages & access

Organising code with packages and controlling visibility.

  1. Packages and importsLesson · 13 minFree
  2. Access modifiersLesson · 13 minFree
  3. Packages & access: interview questions & scenariosInterview Q&AFree

Module interview question bank

Finish the module

Module interview question bank

Every interview question worth practising for Java Fundamentals, grouped by topic, with model answers, how to say them and what-if follow-ups.

44 questions · 23 what-if follow-ups6 topic question sets

Premium