Use Online Java Developer Tests to Identify and Hire Top Talent

What is Core Java?

Java is an OOP based high-level programming language. It’s a brainchild of Sun Microsystems, a company later acquired by the Oracle Corporation. Core Java is a non-standard definition coined by Sun Microsystems to explain the Java Standard Edition (Java SE). 

Besides being the essential and sturdiest Java version, it lends itself well to other Java editions. A good Core Java developer should be proficient in Java and Object-Oriented Programming concepts and have ample experience in Java general-purpose packages.

What concepts are included in the Core Java?

Core Java concepts are useful in building general applications. They are as follows:

  • Object-oriented programming concepts (OOP) 
  • String handling
  • Basic Java constructs
  • Multithreading
  • Exception handling
  • Collection framework
  • Serialization and Deserialization
  • Generics
  • Concurrent collection
  • Synchronization

Where is the Core Java used?

Core Java is a stepping stone to learn advanced Java. Learners need to master the basics of  Java first before taking up an advanced level. Core Java is essential to determine if one wants to deep dive into other advanced versions of the programming language. It comes in handy for designing application software for desktop and server environments.

About Core Java Developer Test

Core Java assessment helps tech recruiters in evaluating the technical skills of candidates for Core Java. Seasoned Java experts have designed and validated these Java programming skills tests in conformity with industry standards.

What do the Core Java Programming Assessment Tests measure?

This java test will help you in measuring:

  • Basics of Java Programming
  • Object-Oriented Programming concepts
  • Knowledge of general-purpose Core Java packages
  • Proficiency in handling exceptions
  • Multithreading programming concepts
  • Hands-on debugging and development skills

Top Customers

Looking for a customised test?

Are you looking for a customised version of this test. Or looking to get a new test build according to your requirements from scratch? Reach out to our subject matter experts and discuss the same.

Why should you use Mercer | Mettl’s Online Core Java test?

The Core Java skills assessment test helps recruiters in many ways, including finding a suitable candidate without difficulty, assisting them in making unbiased hiring decisions, and providing detailed attention on every topic. Consequently, it reduces the administrative burden of conducting assessments at scale.

Mettl’s online aptitude test for Core Java helps in finding those candidates who are well-versed with programming. Below is a list of critical skills that most recruiters look for:

  • Knowledge of OOP concepts
  • Familiarity with features like polymorphism, interfacing, class overriding, and interfacing
  • Proficiency in Streams, Java 8 Lambda, and other functional interfaces

Hiring managers can use in-depth insights from the test to find the best-fit candidates. Evaluating candidates with Java skills tests online is a reliable process in a secure, controlled environment. That’s why conducting assessments become safe and convenient with features such as limited system access, webcam proctoring, and window violation. The Core Java online coding test is ideal for identifying the skills that a professional would be expected to possess.

Number of Sections  4
Number of Questions 20
Test Duration 60 Minutes
Test Language English


Sectional Details:


Hands-on Coding Assesses a candidate's debugging skills in Java, along with problem-solving and development skills No. of Problems:2
Technical Skills Assesses a candidate’s necessary skills in Java and familiarity with technical concepts, for instance, Object-Oriented Programming concepts, packages, exception handling, and multithreading

4 MCQ/MCA items based on Java basics


8 MCQ/MCA items to test Object-Oriented Programming concepts


6 MCQ/MCA items to test proficiency in advanced topics such as packages, exception handling and multithreading

Candidates with work experience of 0.5-2 years can take the test. 

Difficulty level: Moderate

Key profiles the Java interview assessment test is useful for:

  • Core Java Developer
  • Junior Java Developer
  • Software Developer (Java)

A Plethora of Advanced Java Online Test Options are Available

Mercer | Mettl provides many different Java tests to assess the basic concepts and coding techniques of candidates. There are multiple versions of the Java programming skills test that you can choose from to simplify the talent assessment process.

Answer to common queries:

Can candidates be benchmarked based on the internal sample set?

Yes, at Mettl, it can be done. Should you need any further information, please write to us, and we will be happy to assist you.

Is it possible to customize the report as per the need?

Yes, we can do it. We have already done it in the past for our clients. Should you need any further information, please write to us, and we will be happy to find the best solution for you.

How can I prepare for a Core Java skills assessment test?

The best way would be by brushing up on these topics to ace the test:

  • In-depth knowledge of operators, basic syntax, keywords, and more
  • Understanding of Methods and data types 
  • Well-acquainted with OOPS concepts, collection framework, exception handling, generics, AWT and Swing, and multi-threading.

What is the OOP concept?

OOP stands for Object-Oriented Programming. There are four major OOP concepts:  inheritance, abstraction, polymorphism, and encapsulation. These concepts are vital to understanding how Java works.

Which type of questions are asked in the Core Java code test?

It’s a comprehensive test that comprises four sections and is an hour-long. The online Java skills assessment test aims at thoroughly gauging the depth and breadth of a candidate’s knowledge across OOP basics, string handling concepts, exception handling, array, and collection framework. The online core java assessment includes the choicest problems to evaluate the candidates' knowledge, ideas, and analytical skills with utmost precision.

What are the skills required for core java?

The primary skills required for acing Java exam questions in an interview are:

  • Ability to write flawless codes on paper and compile them
  • Ability to use a debugger for debugging and application profiling
  • Well-acquainted with all the primitive data types and operators 
  • Strong knowledge of the class loading process 
  • Ability to handle multiple threads both accurately 
  • Well-versed in using checked exceptions, enums, and generics
  • An in-depth understanding of garbage collection
  • Ability to use java design patterns such as Singleton, Fly-weight, Factory, Builder, Iterator, Object Pool, Strategy, Composite, Visitor

Why should you use our Java programming skills test?

With Mercer | Mettl's Java online tests, building a team of competent and skilled developers is easy. The Java developer test is best suited for assessing aspirants’ Java skills and assisting recruiters in avoiding bad hiring decisions. Choose our Java coding test to interview and evaluate your candidates for job fit. We cater to 2900+ Clients in 80+ Countries. Mercer | Mettl is currently serving 50+ Fortune 500 companies. 

Either choose a tailor-made advanced Java online test from our extensive test library or create your assessment by either using our questions or adding yours as per the job-specific competency framework. We serve customized assessments across the employee lifecycle, including candidate skills assessment, pre-employment screening, training, and development programs for students/employees, certification exams, competitions, and more.

The Java assessment test gauges the depth and breadth of candidates' programming knowledge in the Core Java language and their expertise in working with the commonly used parts of the Java Class Library. Mettl's Java developer test is a great option to help you conduct pre-employment screening with incredible ease. A competent Java developer can solve complex problems using Java and utilize the Java Class Library functionality to write clean and robust code. This online Java assessment requires test-takers to solve code challenges in Java and detect and fix bugs in a Java program.

What are the Java programs asked in interviews?

By asking the candidates questions on Java online coding tests for interviews, recruiters can assess the programming skills with the utmost accuracy and ease. In the interview, some of the most commonly asked questions about Java programs are from the array, control statements, oops, string, etc. Interviewers love asking these basic Java programs: prime numbers, Fibonacci series, palindrome numbers, factorial numbers, and more. Listed below are some Java programs that form the core of the java coding test for interviews:

  • Java Basic Programs
  • Java Array Programs
  • Java String Programs
  • Java Matrix Programs
  • Java Searching and Sorting Programs
  • Java Conversion Programs
  • Pattern programs
  • Singly Linked List Programs
  • Doubly Linked List Programs
  • Circular Linked List Programs
  • Tree Programs

What is Java Code Testing?

Java code tests assess your Java source code against industrial coding standards. This testing ensures that your Java source is consistent, optimized, stable, compliant, and portable. There is limited scope for errors in automated java code testing as compared to manual code testing. Java code testing ensures a comprehensive, thorough review that fulfills all criteria. Automated Java code testing saves cost and improves the application quality by performing functional testing or code review. It is also useful in quality control and enforcing coding standards. 

What are Java testing programs?

Picking a specific testing program/tool seems to baffle many programmers - there are many open-source alternatives available. That's why you need to understand your testing requirements and then go for it. We've listed below some of the most common Java testing programs in no particular order:

  • TestNG
  • JUnit
  • Selenium
  • FitNesse
  • Apache JMeter

What are some of the most commonly asked Java programming test questions and answers?

There is no such thing as the best Java interview questions, but we can include some of the most popular questions and answers that interviewers usually ask during an interview. Listed below are some of them:

What are the main OOP concepts?

  • Inheritance
  • Polymorphism
  • Encapsulation

What are Daemon threads in Java?

Daemon threads in Java act as service providers for objects running in the same process as the daemon thread or other threads. Daemon threads support background tasks and come into play while normal threads are executing. If normal threads are not running and only daemon threads are remaining, then in that case, the interpreter exits. 

What is a Singleton Pattern? Can you make it thread-safe and fast?

The singleton pattern is a software design pattern used to ensure that a class has one instance while offering a global access point to that instance. 

What is JSON, and how to read a JSON object from a file?

JavaScript Object Notation, popularly known as JSON, is a lightweight data-interchange format (LDIF). It is easy to read and write and is easy for machines to parse and generate. It is based on the JavaScript Programming Language subset.

Do you know about HashMap, ConcurrentHashMap, and SynchronizedMap? Which one would you prefer?

HashMap is a compelling data structure in Java. It is used every day in all applications. 

What are the interface and abstract class in Java?

This question is often asked in an interview. An interface is used to implement a class. The interface contains abstract methods and cannot be instantiated, but classes that implement interfaces can!  Interfaces don't include instance variables, but they can consist of constant class variables.

Abstract class includes an abstract keyword in its declaration and must have at least one abstract method. It includes various concrete methods. You can create blueprints for concrete classes using abstract classes. However, the inheriting class should utilize the abstract method.

What Java Programmers should learn in 2020?

In this rapidly-changing world, Java developers need to stay abreast of programming trends. Based on a survey report on some of the most sought-after future skills in Java, we've listed below fifteen topics that a Java developer should learn in 2020:

  • Git 
  • DevOps
  • Spring Framework 5
  • Java 9–14
  • RESTful Web Service
  • Unit testing
  • Spring Boot 2
  • Spring Security 5.0
  • Android
  • Angular 2+ or React JS
  • Docker and Kubernetes
  • Apache Spark and Kafka
  • Cloud (AWS)
  • Microservices
  • Concurrency

Is java developer a promising career in 2020?

In 2020, Java is still an essential programming language for software development. Whether developers look for a gig opportunity or a job at a software development company, Java is still a preferred choice of most developers and helps conduct numerous projects without considering the business sector, field, or type of program. Given its versatility, thriving community, multifaceted applications, Java continues to be the most commonly-used programming language in the technology sector.

How do you evaluate a java developer?

Online Java programming tests for beginners and junior-level developers help employers hire a job-fit candidate in a short period, enabling them to take unprejudiced employee performance appraisal decisions and simplify the process of mass recruitment. The Java interview assessment test allows recruiters to analyze candidates' written codes via various test cases using a coding simulator. Evaluators will also receive an in-depth report for each test case execution.

Java skills assessment test focuses on Java questions and is available in English. The test comprises questions presented as coding challenges and MCQ questions. The candidate needs to solve all the problems in one hour. The test is created from a database of twenty questions dealing with the following topics:

  • Java core language
    Arrays and collections, flow control, generics, basic classes and objects, classes and interfaces, types and casting
  • Applied Java
    Such questions include typical practical problems, database management, regular expressions, file handling, etc.
  • Java objects and designs
    Advanced object-oriented concepts and reflective design patterns
  • Algorithms
    The Java assessment test also includes algorithmic questions that intend to assess the candidate's ability to solve a mathematical problem using the language.

What are the skills required for a Java developer?

While this isn’t an extensive list, listed below are some essential skills required to become a Java developer:

Basic skills

  • Object-oriented programming (OOP) concepts and patterns
  • JavaServer Pages and servlets
  • Web frameworks 
  • Service-oriented architecture
  • Web technologies such as CSS, HTML, JavaScript, and JQuery
  • Markup languages such as JSON and XML 
  • Constructors
  • Abstract classes and interfaces
  • Collections: lists, maps, sets
  • File I/O and serialization
  • Generics
  • Access specifiers
  • Exceptions (checked and unchecked)
  • Java virtual machine and memory management
  • Java keywords: static, final, volatile, synchronized, etc.
  • Dependency injection
  • Synchronization in Java

Advanced skills 

Given below are some advanced skills that experienced Java professionals should possess:

  • Blockchain
  • AI and machine learning
  • Python
  • Amazon Web Services
  • Hadoop/Big Data
  • Advanced JavaScript framework (e.g., React, Angular, VueJS)
  • Mobile technologies (Android or OS)
  • Microservices

What is the role of Java Developer?

A Java developer performs many responsibilities from conceptualization and design to testing, overseeing many functions throughout the application development lifecycle. Some of these responsibilities are listed below: 

  • Plan, conduct, and maintain phases of Java application
  • Perform software analysis, testing and debugging, programming 
  • Detecting and rectifying production/non-production application issues 
  • Create, test, execute and maintain the app
  • Suggest essential changes to refine existing Java application processes 
  • Prepare technical designs for app development
  • Create app code for Java programs

How it works:

step 1

Add this test to your tests

step 2

Share test link from your tests

step 3

Candidate take the tests

step 4

You get their tests report

Note You will be charged only at step 3. i.e. only when candidate start the test.

Relevant for Industries

  • IT
  • ITeS

Related Tags