PracticeTest what you know.
Test what you know.
111 questions, instant feedback.
Each quiz shuffles its questions and explains every answer. Your best score is saved in this browser.
15 questionsCore Java & OOPStrings, equality, inheritance, exceptions, generics and initialization order.Not attempted yet16 questionsCollections & StreamsHashMap internals, choosing collections, iterators, lambdas, streams and collectors.Not attempted yet14 questionsModern Java (17–21)Records, sealed types, pattern matching, switch expressions, var, text blocks and sequenced collections.Not attempted yet16 questionsConcurrency & the JVMThreads, executors, the memory model, locks, atomics, CompletableFuture, GC and class loading.Not attempted yet16 questionsSpring Core & Boot 4DI, bean scopes, auto-configuration, configuration, AOP proxies, REST and what changed in Spring Boot 4.Not attempted yet16 questionsData, Security & ProductionJPA and transactions, Spring Security and JWT, testing, caching, Kafka and resilience.Not attempted yet18 questionsDesign Patterns & SOLIDSOLID and the Gang of Four patterns — intent, structure, trade-offs and real-world usage.Not attempted yet