Provyn Prep · Java competency
Object model & collections in the Java assessment
Object model & collections is one of the areas a Provyn Java credential scores separately, so a recruiter can see it on its own rather than averaged into one number. This guide explains what it covers, how it is tested and what to practice.
What it covers
Classes, access modifiers, equals and hashCode, strings, records, generics and the collections framework.
Topics in the practice set for this area
- modifiers
- strings
- equality
- collections
- generics
- records
- visibility
How it is tested
In the timed assessment, questions in this area use these formats: fill-in-the-blank code, matching, multiple choice, short answer. Each attempt draws its own set of questions, and this area gets its own sub-score on the credential when the attempt includes enough questions from it. The assessment questions themselves are never published; the practice set below is written separately for study.
What to practice
- Implement equals and hashCode for a class and test it as a HashMap key.
- Choose between ArrayList, LinkedList, HashMap and TreeMap for small problems and explain the cost of each.
- Write a generic method with a bounded type parameter.
Try a practice question
From the free practice set (10 questions in this area). Answers and explanations are in the practice set.
- Which Java keyword prevents a class from being subclassed?
- `String s = "a" + "b";` compiles to roughly:
- Difference between `==` and `.equals()` on Strings?
Practice before the real thing
Both are free and use practice questions only, never questions from the real assessment.
More Java study guides
Last reviewed 2026-10-06.