Learn Java
Java quizzes concentrate on the places students lose marks: references versus values, object-oriented design, collections and exceptions.
Written against Java 17+.
What you will practise
- Types, strings and reference semantics
- Classes, inheritance and interfaces
- Collections and generics
- Exceptions and resource handling
Roadmap
Work through the levels in order, or jump to where you are.
Advanced
Collections & exceptions
- HashMap and equals/hashCode
- Iteration pitfalls
- Checked exceptions
- try-with-resources
Java quizzes
- JavaBeginner
Java Fundamentals
Types, strings, arrays and references
TypesStringsReferences7 Qs~5mStart - JavaIntermediate
Object-Oriented Java
Polymorphism, inheritance, static and final
PolymorphismInterfacesOverriding7 Qs~5mStart - JavaAdvanced
Collections & Exceptions
Maps, iteration pitfalls and error handling
HashMapListsIteration8 Qs~6mStart
Interactive Java challenges
Hands-on activities: find bugs, complete code, order steps and match concepts.
Java articles
Java: == vs equals() and Why Strings Trip Everyone Up
What == really compares in Java, why new String("a") differs from "a", and how to write reliable comparisons for strings and your own classes.
Java OOP Concepts Explained: Encapsulation, Inheritance, Polymorphism and Abstraction
The four object-oriented pillars in Java with short examples, the difference between abstract classes and interfaces, and why composition often beats inheritance.
Spring Boot REST API for Beginners: Build Your First Endpoint
A step-by-step introduction to creating a Spring Boot project, writing a REST controller and running it, with the annotations you need and the mistakes beginners make.
FAQ
Which Java version is assumed?
Java 17 or newer. Features such as List.of need Java 9+.
Is Java still relevant for students?
Absolutely. It remains the backbone of enterprise software and Android development, and is highly requested by campus recruiters.
Do these quizzes cover Spring Boot?
No. These quizzes test core Java fundamentals (Core Java). Spring Boot is a separate topic entirely.