Java Quiz | Level Up Your Java Skills Last Updated : 22 Jun, 2025 Comments Improve Suggest changes Like Article Like Report The best way to scale up your coding skills is by practicing the exercise. And if you are a Java programmer looking to test your Java skills and knowledge? Then, this Java quiz is designed to challenge your understanding of Java programming concepts and assess your excellence in the language. In this online Java quiz page, we will learn about everything from basic to advanced topics. This quiz covers all the topics of Java programming. So, whether you are a beginner or an experienced Java developer, this Java Programming Quiz will help you scale up your Java skills and identify areas for improvement. No registration is required to start the test. Simply choose a test and begin your Java journey.Java Basics and IdentifiersVariables, OperatorControl Statements and LoopsMethodsJava ArraysArray ProgramsString BasicsString ClassesClasses and ObjectsConstructorsInheritance and AbstractionPolymorphism and PackagesInterfacesInterface types and ComparatorCollectionList, ArrayList, LinkedListSet and HashSetQueue and Map InterfaceIterators, Comparator vs ComparableJava ExceptionsException HandlingThread Basics and LifecycleThread Methods and Daemon Threads File Handling File Writing Lambda Expressions and Streams IO BasicsBufferedReader vs Scanner and Fast I/OSynchronization BasicsDeadlocks and SynchronizationConcurrency Locks and Reentrant LocksRegex Basics and Pattern MatchingNetworking Basics and ProtocolsSockets and Server CommunicationJDBCJava Memory AllocationHeap vs StackJVM Memory Management and Garbage Collection Comment More infoAdvertise with us Next Article Top 50 Java Project Ideas For Beginners and Advanced [Update 2025] kartik Follow Improve Article Tags : Java Practice Tags : Java Similar Reads Java Tutorial Java is a high-level, object-oriented programming language used to build web apps, mobile applications, and enterprise software systems. It is known for its Write Once, Run Anywhere capability, which means code written in Java can run on any device that supports the Java Virtual Machine (JVM).Java s 10 min read BasicsIntroduction to JavaJava is a high-level, object-oriented programming language developed by Sun Microsystems in 1995. It is platform-independent, which means we can write code once and run it anywhere using the Java Virtual Machine (JVM). Java is mostly used for building desktop applications, web applications, Android 4 min read Java Programming BasicsJava is one of the most popular and widely used programming language and platform. A platform is an environment that helps to develop and run programs written in any programming language. Java is fast, reliable and secure. From desktop to web applications, scientific supercomputers to gaming console 4 min read Java MethodsJava Methods are blocks of code that perform a specific task. A method allows us to reuse code, improving both efficiency and organization. All methods in Java must belong to a class. Methods are similar to functions and expose the behavior of objects.Example: Java program to demonstrate how to crea 8 min read Access Modifiers in JavaIn Java, access modifiers are essential tools that define how the members of a class, like variables, methods, and even the class itself can be accessed from other parts of our program. They are an important part of building secure and modular code when designing large applications. Understanding de 7 min read Arrays in JavaArrays in Java are one of the most fundamental data structures that allow us to store multiple values of the same type in a single variable. They are useful for storing and managing collections of data. Arrays in Java are objects, which makes them work differently from arrays in C/C++ in terms of me 15+ min read Java StringsIn Java, a String is the type of object that can store a sequence of characters enclosed by double quotes, and every character is stored in 16 bits, i.e., using UTF 16-bit encoding. A string acts the same as an array of characters. Java provides a robust and flexible API for handling strings, allowi 9 min read Regular Expressions in JavaIn Java, Regular Expressions or Regex (in short) in Java is an API for defining String patterns that can be used for searching, manipulating, and editing a string in Java. Email validation and passwords are a few areas of strings where Regex is widely used to define the constraints. Regular Expressi 7 min read OOPs & InterfacesClasses and Objects in JavaIn Java, classes and objects are basic concepts of Object Oriented Programming (OOPs) that are used to represent real-world concepts and entities. The class represents a group of objects having similar properties and behavior, or in other words, we can say that a class is a blueprint for objects, wh 11 min read Java ConstructorsIn Java, constructors play an important role in object creation. A constructor is a special block of code that is called when an object is created. Its main job is to initialize the object, to set up its internal state, or to assign default values to its attributes. This process happens automaticall 10 min read Java OOP(Object Oriented Programming) ConceptsJava Object-Oriented Programming (OOPs) is a fundamental concept in Java that every developer must understand. It allows developers to structure code using classes and objects, making it more modular, reusable, and scalable.The core idea of OOPs is to bind data and the functions that operate on it, 13 min read Java PackagesPackages in Java are a mechanism that encapsulates a group of classes, sub-packages, and interfaces. Packages are used for: Prevent naming conflicts by allowing classes with the same name to exist in different packages, like college.staff.cse.Employee and college.staff.ee.Employee.They make it easie 8 min read Java InterfaceAn Interface in Java programming language is defined as an abstract type used to specify the behaviour of a class. An interface in Java is a blueprint of a behaviour. A Java interface contains static constants and abstract methods. Key Properties of Interface:The interface in Java is a mechanism to 12 min read CollectionsCollections in JavaAny group of individual objects that are represented as a single unit is known as a Java Collection of Objects. In Java, a separate framework named the "Collection Framework" has been defined in JDK 1.2 which holds all the Java Collection Classes and Interface in it. In Java, the Collection interfac 15+ min read Collections Class in JavaCollections class in Java is one of the utility classes in the Java Collections Framework. The java.util package contains the Collections class in Java. The Java Collections class is used with the static methods that operate on the collections or return the collection. All the methods of this class 13 min read Collection Interface in JavaThe Collection interface in Java is a core member of the Java Collections Framework located in the java.util package. It is one of the root interfaces of the Java Collection Hierarchy. The Collection interface is not directly implemented by any class. Instead, it is implemented indirectly through it 6 min read Java IteratorAn Iterator in Java is an interface used to traverse elements in a Collection sequentially. It provides methods like hasNext(), next(), and remove() to loop through collections and perform manipulation. An Iterator is a part of the Java Collection Framework, and we can use it with collections like A 6 min read Java Comparator InterfaceThe Comparator interface in Java is used to sort the objects of user-defined classes. The Comparator interface is present in java.util package. This interface allows us to define custom comparison logic outside of the class for which instances we want to sort. The comparator interface is useful when 7 min read Exception HandlingJava Exception HandlingException handling in Java allows developers to manage runtime errors effectively by using mechanisms like try-catch block, finally block, throwing Exceptions, Custom Exception handling, etc. An Exception is an unwanted or unexpected event that occurs during the execution of a program, i.e., at runt 10 min read Java Try Catch BlockA try-catch block in Java is a mechanism to handle exceptions. This make sure that the application continues to run even if an error occurs. The code inside the try block is executed, and if any exception occurs, it is then caught by the catch block.Example: Here, we are going to handle the Arithmet 4 min read Java final, finally and finalizeIn Java, the final, finally, and finalize keywords play an important role in exception handling. The main difference between final, finally, and finalize is listed below:final: The final is the keyword that can be used for immutability and restrictions in variables, methods, and classes.finally: The 4 min read Chained Exceptions in JavaChained Exceptions in Java allow associating one exception with another, i.e. one exception describes the cause of another exception. For example, consider a situation in which a method throws an ArithmeticException because of an attempt to divide by zero.But the root cause of the error was an I/O f 3 min read Null Pointer Exception in JavaA NullPointerException in Java is a RuntimeException. It occurs when a program attempts to use an object reference that has the null value. In Java, "null" is a special value that can be assigned to object references to indicate the absence of a value.Reasons for Null Pointer ExceptionA NullPointerE 5 min read Exception Handling with Method Overriding in JavaIn Java, an exception is an unwanted or unexpected event that occurs during a program's execution, i.e., at runtime, and disrupts the normal flow of the program’s instructions. Exception handling in Java handles runtime errors and helps maintain the program's normal flow by using constructs like try 5 min read Java AdvancedJava Multithreading TutorialThreads are the backbone of multithreading. We are living in the real world which in itself is caught on the web surrounded by lots of applications. With the advancement in technologies, we cannot achieve the speed required to run them simultaneously unless we introduce the concept of multi-tasking 15+ min read Synchronization in JavaIn multithreading, synchronization is important to make sure multiple threads safely work on shared resources. Without synchronization, data can become inconsistent or corrupted if multiple threads access and modify shared variables at the same time. In Java, it is a mechanism that ensures that only 10 min read File Handling in JavaIn Java, with the help of File Class, we can work with files. This File Class is inside the java.io package. The File class can be used to create an object of the class and then specifying the name of the file.Why File Handling is Required?File Handling is an integral part of any programming languag 6 min read Java Method ReferencesIn Java, a method is a collection of statements that perform some specific task and return the result to the caller. A method reference is the shorthand syntax for a lambda expression that contains just one method call. In general, one does not have to pass arguments to method references.Why Use Met 9 min read Java 8 Stream TutorialJava 8 introduces Stream, which is a new abstract layer, and some new additional packages in Java 8 called java.util.stream. A Stream is a sequence of components that can be processed sequentially. These packages include classes, interfaces, and enum to allow functional-style operations on the eleme 15+ min read Java NetworkingWhen computing devices such as laptops, desktops, servers, smartphones, and tablets and an eternally-expanding arrangement of IoT gadgets such as cameras, door locks, doorbells, refrigerators, audio/visual systems, thermostats, and various sensors are sharing information and data with each other is 15+ min read JDBC TutorialJDBC stands for Java Database Connectivity. JDBC is a Java API or tool used in Java applications to interact with the database. It is a specification from Sun Microsystems that provides APIs for Java applications to communicate with different databases. Interfaces and Classes for JDBC API comes unde 12 min read Java Memory ManagementJava memory management is a fundamental concept that involves the automatic allocation and deallocation of objects, managed by the Java Virtual Machine (JVM). The JVM uses a garbage collector to automatically remove unused objects, freeing up memory in the background. This eliminates the need for de 5 min read Garbage Collection in JavaGarbage collection in Java is an automatic memory management process that helps Java programs run efficiently. Java programs compile to bytecode that can be run on a Java Virtual Machine (JVM). When Java programs run on the JVM, objects in the heap are created, which is a portion of memory dedicated 7 min read Memory Leaks in JavaIn programming, a memory leak happens when a program keeps using memory but does not give it back when it's done. It simply means the program slowly uses more and more memory, which can make things slow and even stop working. Working of Memory Management in JavaJava has automatic garbage collection, 3 min read Practice JavaJava Interview Questions and AnswersJava is one of the most popular programming languages in the world, known for its versatility, portability, and wide range of applications. Java is the most used language in top companies such as Uber, Airbnb, Google, Netflix, Instagram, Spotify, Amazon, and many more because of its features and per 15+ min read Java Programs - Java Programming ExamplesIn this article, we will learn and prepare for Interviews using Java Programming Examples. From basic Java programs like the Fibonacci series, Prime numbers, Factorial numbers, and Palindrome numbers to advanced Java programs.Java is one of the most popular programming languages today because of its 8 min read Java Exercises - Basic to Advanced Java Practice Programs with SolutionsLooking for Java exercises to test your Java skills, then explore our topic-wise Java practice exercises? Here you will get 25 plus practice problems that help to upscale your Java skills. As we know Java is one of the most popular languages because of its robust and secure nature. But, programmers 7 min read Java Quiz | Level Up Your Java SkillsThe best way to scale up your coding skills is by practicing the exercise. And if you are a Java programmer looking to test your Java skills and knowledge? Then, this Java quiz is designed to challenge your understanding of Java programming concepts and assess your excellence in the language. In thi 1 min read Top 50 Java Project Ideas For Beginners and Advanced [Update 2025]Java is one of the most popular and versatile programming languages, known for its reliability, security, and platform independence. Developed by James Gosling in 1982, Java is widely used across industries like big data, mobile development, finance, and e-commerce.Building Java projects is an excel 15+ min read Like