Java interview questions and answers for 2023
It takes some grind to ace a Java interview. So, how will you swim through your advanced java interview questions? Or, how will you find the bright minds who can answer core java interview questions like they were primary math questions? Whether you are an experienced Java developer or a recruiter seeking the best Java developers, we encourage you to go through the following docket of Java interview questions. We hope it will help you find your dream job or dream candidate.
Are you well-prepared for your next Java interview? or are you a hiring manager looking out for the right talent for your Java project, we have got you covered with a comprehensive list of Java questions to help consolidate your knowledge and concepts of Java.
Java is one of the programming languages that are very high in demand. Many applications are built and maintained by this incredible language, more reason for anyone to invest time in learning and developing their skills. And so, there has been a rapid growth in the number of Java development companies looking to hire the best Java developer Below, are some of the most commonly asked Java interview questions and answers related to Java from which both developers and companies can benefit from.
This blog will give you a guide in preparation of interviews for elite US companies and help you to know which parts of the language you should develop in-depth knowledge in from beginner-friendly questions to the most advanced ones.
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Java interview questions and answers (19)Intermediate Java interview questions and answers (18)Advanced Java interview questions and answers (68)Java interview questions and answers
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Intermediate Java interview questions and answers
1.
What is the difference between the creation of a string using new() and that of literal?
A new object is created when using new() whereas using literal, the object already existing might return with the same name.
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What is the importance of synchronization?
Synchronization helps to execute threads one after another. It also prevents memory constituency errors due to shared access methods.
3.
Does Java use Pointers and give a reason?
Java does not use pointers. This is because they are not safe and can increase the complexity of the program. Pointers are the exact opposite of Java’s simplicity.
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How is an object in Java created?
A real entity that has a state and behavior is called an object. It is created using the new keyword. State, identity, and behavior are some of the characteristics of an object created.
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What is OOP?
OOP is an abbreviation for Object-Oriented Programming. It is a model where programs are organized around objects rather than functions and logic. Its main focus is on objects more than using logic and is mainly preferred for large and complex codes.
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What is Double Brace Initialization?
Double Brace Initialization is a technique that combines an anonymous inner class with an initialization block in order to initialize collections and improve code readability.
7.
Define an Association
An association can be defined as a relationship between two or more that have no ownership over another.
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What is a Singleton class in Java?
A singleton class is a class that is capable of possessing only one object at a time.
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Define a Java string pool
The Java string pool is a repository of strings stored in the Java virtual machine (JVM). The pool stores only one instance of each literal string.
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What is the difference between JVM and JRE?
JRE has class libraries and other JVM files however, it does not have any tools for Java development such as a debugger and compiler. While JVM has a Just In Time(JIT) tool to convert all the Java codes into compatible machine language.
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What is method overloading in Java?
It's a process of creating multiple method signatures using one method. There are two ways of achieving this i.e changing the return type of the method and varying the number of arguments.
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What are the five stages of a thread’s lifecycle?
The stages of a thread’s lifecycle are as follows:
Newborn state- This is where a new thread is created. In this newborn state, the code has not been run or executed as yet.
Runnable state- A thread that is ready to run is put into the runnable state. The code may be running or ready to run at any given time but at this stage, the thread scheduler provides the time for the thread to run.
Running state- This stage is when the thread receives a CPU moving from the runnable to the running state.
Blocked state- When the thread is inactive for a period of time temporarily, the thread is said to be in a blocked state.
Dead state- Also known as the terminated state. This is when the thread has either finished its job and exists or when some unexpected event occurs such as a segmentation fault.
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Define what is enumeration in Java
Enumeration also known as enum, is an interface in Java. It allows the sequential access of the elements stored in the collection.
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Can you define Java packages and their significance?
Java packages can be defined as a collection of classes and interfaces which are bundled together while they relate to one another. It also helps developers to group a code for reuse and after being packaged it can be imported in other classes for repurposing.
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What is JPA?
JPA stands for Java Persistence API. It enables developers to create the persistence layer for desktop/ web applications.
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Why is Java considered dynamic?
Java is designed to adapt to any environment that is evolving. Its program has a large amount of information that is used to solve or access objects in real-time.
17.
What are the steps involved when connecting to a database in Java
Steps needed to connect to a database in Java are as follows:
- Registering the driver class
- Creating connection
- Creating statement
- Executing queries
- Closing connects
18.
How is an object serialized in Java?
To convert an object, an interface with the name serializable is implemented by the class. All the objects of a class implementing a serializable interface get serialized and their state is saved in the byte stream.
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Advanced Java interview questions and answers
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Wrapping up
We have listed some of the most asked Java interview questions and answers, that will help you prepare for technical interviews. Apart from the basic interview questions, it is important to develop soft skills while in the process as this will help excel increase your chances of landing your desired position. If you feel confident and ready to solve some Java challenges, do take the Turing Java test and be counted among the best Java candidates in the global pool. Also, if you are a hirer looking out for an easier approach to hire the best talent for your Java project, you can contact Turing which helps you source,vet and manage the best Java developers remotely.
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