17 Common Java Coding Interview Questions (With Example Answers)
17 Common Java Coding Interview Questions (With Example Answers)
By Tegan Griffiths
Updated June 3, 2022 | Published January 28, 2020 Updated June 3, 2022 Published January 28, 2020TwitterLinkedInFacebookEmail Tegan Griffiths is a technical writer with a love for everything from artificial learning to machine learn. Tegan presently writes content for an association magazine in the technical school commercial enterprise. If you ‘re preparing to interview for a job that requires cognition of Java, it ‘s significant to learn about some of the coarse questions the rent coach may ask. Practicing your responses can help you feel more confident when responding to questions or writing test code. Though the questions the interviewer asks deviate, you can rehearse your responses to help refresh your cognition of Java. In this article, we review why Java is a democratic terminology among employers and provide examples of Java coding interview questions and answers to help you prepare .
Why is Java coding popular among employers?
One of the biggest reasons Java is popular among employers is because of its independence. deoxyadenosine monophosphate retentive as your computer has the Java Runtime Environment, you can execute a Java program on your computer. Most computers can handle a JRE, including Macintosh, Linux, Unix, Windows and selective mobile phones. Features that make Java programming popular include :
- It ‘s easy to learn and implement .
- Any code written with Java can run on about any computing platform .
- The code is robust enough to independently run Java programs without any external dependencies .
- Java has experienced coherent exploitation .
- It ‘s a memory management and multithreaded program linguistic process .
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Common Java code interview questions
Interviewers normally ask basic Java code questions in interviews along with some theoretical aspects. You might be asked questions or tasks like these :
- Write a Java program to swap two numbers using the third variable .
- Write a Java program to swap two numbers without using the third gear variable .
- Write a Java platform to find whether a number is prime or not .
- Write a Java program to find the twin characters in a string .
- Write a Selenium code to switch to the previous check .
- What is an abstraction class ? How are abstract classes alike or different in Java from C++ ?
- How is inheritance in C++ different from Java ?
- What is object cloning ?
- What are the differences between HashMap and HashTable in Java ?
- Can you overload or override electrostatic methods in Java ?
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7 Java coding interview questions and answers
here are seven Java questions along with sample answers to help you prepare :
1. Why is Java known as the “platform-independent programming language”?
Interviewers ask this motion because they want to determine whether you know the basic features and foundations of Java code and their real-world benefits. When answering this question, make it unclutter to the interviewer you know the platform independence sport was one of the primary coil purposes for creating Java code and how this feature of speech creates real-world benefits in application. You can show the real-world application benefits of this feature by describing a specific example of code you have written on one chopine that runs across multiple platforms. model answer : “ One of the chief purposes for Java code was to create a program terminology that developers could use across multiple platforms without having to change the beginning code for each platform. Platform independence means the execution of your program is not dependent on the function system being used. Earlier scheduling languages, such as C and C++, command developers to compile offprint beginning code for every operational arrangement they run it on. For example, at my last job, I wrote Java code using a Linux operate on system. We could then run this byte code on any early operational organization, such as Microsoft or MAC, by converting the code using the Java Virtual Machine, which is available to install on all operate systems. This saved the developers time as we only have to write the source code once. ”
2. Give an example of a time when you worked with a team to solve a problem.
An interviewer might ask this question to determine your ability to work with a team and if you can add to their company culture. When answering this motion, focus on the skills that would make you an asset to the company ‘s team and how you have used those skills to successfully complete team projects in the by. exercise answer : “ In my anterior character, I was a member of a team of developers working on an enterprise-class application to develop a customer relationship management system. Our team functioned by assigning each developer a different assemble of code to write. After I finished writing the code assigned to me, I helped the team finish the project early by helping other developers work on their code. ” Related : Java Interview Questions for Experienced Programmers
3. How do you reverse a string in Java?
There is no reverse utility provided in Java. Hiring managers might ask this question to determine your cognition of Java and your problem-solving skills. You can create a character array from the string and iterate it from the end to the begin. You can append the characters to a string builder and finally return the turn back string. exemplar answer :
4. Write a Java program for the Fibonacci series.
This wonder is another specific exercise that can show your cognition of using Java code to complete a task. The interviewer probably wants to see that you can arrive at the correct solution in an satisfactory come of time. This is an ideal time to explain your process aloud as you write your code to show the interviewer your think process. exercise answer : output :
5. Write a Java program to show scroll up and scroll down.
This wonder is a basic tax that you could receive regardless of your experience level. Remember to explain your action cautiously as you write the lines. case answer :
6. Write a Java program to reverse a string without using string inbuilt function.
This is another specific Java code exercise the interviewer could use to test your Java cognition and experience. exercise suffice : output :
7. What are constructors in Java?
Constructors refer to code that is used to initialize an object ‘s state in Java. Employers ask this question to determine whether you have an understanding of the basics of the programming linguistic process. other questions such as, ‘Are there transcript constructors in Java ? ‘ and, ‘What is builder chaining ? ‘ are variations of the question. exercise answer : “ A builder initializes a newly created object. Java supports copy builder, but you have to write your own code to do it. Constructor chain is calling a builder from another builder. however, you can not call a sub-class builder using a super-class builder. ”
Tips to prepare for a Java-based interview
Java is wide and has thousands of concepts, but interviewers are probable to focus on a detail determined of concepts for the interview. As you prepare for your interview, keep these tips in mind :
Practice answering the questions with your friends or family or in front of your mirror. Consider your facial expressions, body terminology and note, all of which can make a positivist impression on the interviewer. Practicing can help you feel more comfortable and convinced about your responses .
Review the job description carefully
The job description typically includes keywords that inform you which technical skills the interviewer wants. Look for keywords such as testing, bugs and app adaptation for entry-level developers. Software management, app design, app development and Java infrastructure may be common for mid-level developers. Mentoring entry-level developers and managing teams could be keywords to look for as a elder developer .
Research the company
many interviewers seek candidates who can contribute promptly to the company ‘s goals and add more to the culture. Review the ship’s company ‘s web site, including its “ About ” or “ Mission ” page, to learn about its environment and objectives. You can use your research to form in-depth questions that show the rent coach you ‘re concerned in the character and the caller .
Prepare for real-time coding
If the interviewer asks you to create a Java broadcast or a solution-based code in real-time, remember to keep them engaged. Communicate with the interviewer and think loudly as you develop your solution. Use “ we ” as opposed to “ I ” throughout the work to show you have a team mentality. Conclude the solution-based challenge with an explanation of what you did and why .
Consider using STAR interview method
The STAR interview technique is a method of developing in-depth responses that thoroughly answer a hire coach ‘s questions. You can provide a comprehensive approach by following these steps :
- situation : Describe an environment where you faced a challenge or where you handled a project. For example, you could describe how you managed a team of programmers .
- job : future, describe the roles you had during the event. possibly you had a deadline and had to lead the team to finish the project by the deadline .
- action : Describe how you completed the tax. Focus on how you influenced the consequence as opposed to what your team did to overcome the challenge .
- result : last, describe the consequence of your approach to the undertaking. You can besides relate what you learned in the role .
You wo n’t need to answer every question using the STAR interview technique. many Java coding consultation questions are technical and require a more calculate solution, but it ‘s normally best to use the STAR method acting when faced with a behavioral-based question. Related : How To Use the STAR Interview Response Please bill that none of the organizations mentioned in this article are affiliated with indeed.
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