Friday, March 1, 2024

How To Prepare For Java Coding Interview

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Question : How To Find Duplicate Characters In String In Java

Java Interview Preparation for 2 Years Experienced | java Coding interview questions

Solution: Here is a solution to find duplicate characters in String.

  • Create a HashMap and character of String will be inserted as key and its count as value.
  • If Hashamap already contains char,increase its count by 1, else put char in HashMap.
  • If value of Char is more than 1, that means it is duplicate character in that String.
  • Q11 How To Create A Custom Exception

    To create you own exception extend the Exception class or any of its subclasses.

    • class New1Exception extends Exception // this will create Checked Exception
    • class NewException extends IOException // this will create Checked exception
    • class NewException extends NullPonterExcpetion // this will create UnChecked exception

    How To List Your Employment History

    If you have a short employment history , then add all of it to the resume. Dont go for your complete employment history if you have a long list of roles . Just choose 4 roles that are the most impressive .

    For each role, follow the Achievement-> Action-> Effect model. Always start with the achievement! This will act as a magnet for the recruiter. Once they read the achievement, youve got their attention to continuing reading.

    For example, lets imagine that you worked at the company Foo and youve managed to increase the performance of the connection pool by 30% by tuning its parameters. Now the application can accommodate a transaction throughput of 15% extra. Add this achievement in the resume in a single statement as follows:

    Increased the connection pool performance by 30% by tuning its parameters, leading to a transaction throughput boost of 15%.

    List the most relevant roles via Achievement-> Action-> Effect statements. Always try to measure the benefits you created. Dont say, I reduced the memory footprint by compressing …, and say, I reduced the memory footprint by 5% by compressing ….

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    Cracking The Coding Interview

    Cracking the Coding Interview: 189 Programming Questions and Solutions by Gayle Laakmann McDowell is the most popular book written on the subject.

    The book goes into pretty deep detail on what to expect for an interview at top tech companies and how to prepare yourself, including tips on writing a good resume and what topics you should study. She then goes on to give lots of pointers for the best approach to answering interview questions.

    Big O notation is such an important topic that it gets a whole chapter to itself. If youre a self-taught developer with no formal Computer Science background, theres a good possibility that youve never even heard of Big O, and this alone will doom your chances in many interviews.

    In a nutshell, Big O notation can be used to describe the efficiency of an algorithm by showing how many operations must be performed relative to the size of the data set. After studying it just a little, you quickly come to see why nested for loops are usually a bad programming solution.

    The bulk of the book is dedicated to technical questions and solutions, along with some tips on how to develop strategies for solving problems that youve never encountered before.

    The author uses Java throughout the book, but it should not be difficult to translate the solutions to whichever programming language you are most familiar with.

    • Arrays and Strings
    • Scala
    • Swift

    Theres also a discussion forum where many users present their versions of solutions.

    What Do You Mean By Data Encapsulation

    Java Coding Interview Questions
    • Data Encapsulation is an Object-Oriented Programming concept of hiding the data attributes and their behaviors in a single unit.
    • It helps developers to follow modularity while developing software by ensuring that each object is independent of other objects by having its own methods, attributes, and functionalities.
    • It is used for the security of the private properties of an object and hence serves the purpose of data hiding.

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    Q5 Will The Finally Block Get Executed When The Return Statement Is Written At The End Of Try Block And Catch Block As Shown Below

    The finally block always gets executed even hen the return statement is written at the end of the try block and the catch block. It always executes , whether there is an exception or not. There are only a few situations in which the finally block does not execute, such as VM crash, power failure, software crash, etc. If you dont want to execute the finally block, you need to call the System.exit method explicitly in the finally block.

    How Should A Beginner Prepare For Coding Interview

    Coding Interview Preparation

  • Prepare a 30-second to 1-minute elevator pitch for the tell me about yourself question. …
  • Before you go, study up on the most important CS fundamentals. …
  • Pick one programming language and know it really well. …
  • Do regular coding challenges/smart practice. …
  • Understand tech fundamentals.
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    Common Java Coding Interview Questions

    Tegan Griffiths is a technical writer with a passion for everything from artificial learning to machine learning. Tegan currently writes content for an association magazine in the tech business.

    If you’re preparing to interview for a job that requires knowledge of Java, it’s important to learn about some of the common questions the hiring manager 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 could vary, you can practice your responses to help refresh your knowledge of Java. In this article, we review why Java is a popular language among employers and provide example Java coding interview questions and answers to help you prepare.

    Related video: Top Interview Tips: Common Questions, Body Language and MoreIn this video, we dissect an entire job interview from start to finish. We analyze everything from common interview questions to etiquette and how to follow up.

    When Can You Use Super Keyword

    Top Resource To Prepare For A Technical Coding Interview (JavaScript, Java, Etc)
    • The super keyword is used to access hidden fields and overridden methods or attributes of the parent class.
    • Following are the cases when this keyword can be used:
    • Accessing data members of parent class when the member names of the class and its child subclasses are same.
    • To call the default and parameterized constructor of the parent class inside the child class.
    • Accessing the parent class methods when the child classes have overridden them.
  • The following example demonstrates all 3 cases when a super keyword is used.

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    How Long The Resume Should Be

    To answer how long a resume should be, you must answer another question: how long do you think a recruiter spends reading a resume? Most likely, around 10-20 seconds. In other words, recruiters read between the lines, trying to quickly identify what interests them.

    In general, a resume should not be longer than a page. If you have 10+ year’s experience, then you can go with 2 pages.

    You may think that it is impossible to condense your vast experience in 1-2 pages, but this is not true. First, prioritize content, and second, add this content until you cover 1-2 pages. Skip the remaining content. Dont worry that the recruiters will not know everything youve done! They will be impressed by your resume highlights and will be happy to discover the rest of your experience in the interview.

    Write a resume that fits on one page.

    If you have 10+ years of experience, then consider two pages. Keep in mind that some recruiters may skip long resumes without reading a single line. They want to find the most impressive items right away. Adding less important items and/or too many words will distract the recruiter and makes them waste time.

    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 language. Other questions such as, ‘Are there copy constructors in Java?’ and, ‘What is constructor chaining?’ are variations of the question.

    Example answer:”A constructor initializes a newly created object. Java supports copy constructor, but you have to write your own code to do it. Constructor chaining is calling a constructor from another constructor. However, you cannot call a sub-class constructor using a super-class constructor.”

    Related video: Top 6 Common Interview Questions and AnswersIn this video, Jenn, an Indeed Career Coach, breaks down the intentions behind employers’ questions and shares strategies for crafting strong responses.

    Please note that none of the organizations mentioned in this article are affiliated with Indeed.

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    What Makes A Hashset Different From A Treeset

    Although both HashSet and TreeSet are not synchronized and ensure that duplicates are not present, there are certain properties that distinguish a HashSet from a TreeSet.

    • Implementation: For a HashSet, the hash table is utilized for storing the elements in an unordered manner. However, TreeSet makes use of the red-black tree to store the elements in a sorted manner.
    • Complexity/ Performance: For adding, retrieving, and deleting elements, the time amortized complexity is O for a HashSet. The time complexity for performing the same operations is a bit higher for TreeSet and is equal to O. Overall, the performance of HashSet is faster in comparison to TreeSet.
    • Methods: hashCode and equals are the methods utilized by HashSet for making comparisons between the objects. Conversely, compareTo and compare methods are utilized by TreeSet to facilitate object comparisons.
    • Objects type: Heterogeneous and null objects can be stored with the help of HashSet. In the case of a TreeSet, runtime exception occurs while inserting heterogeneous objects or null objects.

    Tip #: Get Outside Support

    java interview questions and answers

    If youre not sure how to practice or feel like youre stuck, seek outside help and knowledge:

    • Ask a friend to conduct a test interview with you and get their feedback.
    • Try to see an actual virtual whiteboard coding interview.
    • Sharpen your communication skills in conversations with friends and family.
    • Find and consume instructional videos, blog posts, and guides on the Internet.
    • Buy or borrow books on the subject.
    • Participate in fun coding challenges

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    Q9 Can You Override A Private Or Static Method In Java

    You cannot override a private or static method in Java. If you create a similar method with the same return type and same method arguments in child class then it will hide the superclass method this is known as method hiding. Similarly, you cannot override a private method in subclass because its not accessible there. What you can do is create another private method with the same name in the child class. Lets take a look at the example below to understand it better.

    class Base public void print class Derived extends Base public void print public class test }

    Q7 What Are The Different Types Of Inheritance In Java

    Java supports four types of inheritance which are:

  • Single Inheritance: In single inheritance, one class inherits the properties of another i.e there will be only one parent as well as one child class.
  • Multilevel Inheritance: When a class is derived from a class which is also derived from another class, i.e. a class having more than one parent class but at different levels, such type of inheritance is called Multilevel Inheritance.
  • Hierarchical Inheritance: When a class has more than one child classes or in other words, more than one child classes have the same parent class, then such kind of inheritance is known as hierarchical.
  • Hybrid Inheritance: Hybrid inheritance is a combination of two or more types of inheritance.
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    The Coding Interview: A Preparation Guide

    Are you feeling a little nervous because you have a coding interview coming up?

    I feel you!

    You are definitely not alone.

    Every person experiences some level of nervousness before big defining moments in their life.

    Especially if this is an interview for your first job then the stakes are pretty high.

    This coding interview is literally the only thing standing between you and making a six-figure income.

    I have been interviewed many times and I remember being a little nervous before every single interview.

    Also now that I am on the other side of the table interviewing candidates, most of the exceptional candidates I have interviewed showed some degree of nervousness as well.

    You cant completely eliminate being nervous but you can absolutely reduce your level of nervousness.

    This is critical because if your level of anxiety is extremely high then you might ruin your chances of getting hired even if you are genuinely competent.

    To get your anxiety under control you need to know what to expect and prepare very well for it.

    Preparation is key.

    And this is exactly what this article is about.

    In this article, I am going to share with you my personal experience both as an interviewee and as an interviewer.

    I will teach you how to get a coding interview in the first place, prepare very well for it, and eventually get hired and kickstart your career.

    Before you proceed, I want you to know that all the information in this article is based on my experience working in the USA.

    But how?

    Q9 What Are Some Of The Important Spring Annotations Which You Have Used

    How to pass a coding interview | Coding interview preparation|Interview tips for software developer

    Some of the Spring annotations that I have used in my project are:

    for controller classes in Spring MVC project.

    for configuring URI mapping in controller handler methods. This is a very important annotation, so you should go through Spring MVC RequestMapping Annotation Examples

    for sending Object as response, usually for sending XML or JSON data as response.

    for mapping dynamic values from the URI to handler method arguments.

    for autowiring dependencies in spring beans.

    with @Autowired annotation to avoid confusion when multiple instances of bean type is present.

    for service classes.

    for configuring the scope of the spring bean.

    for java based configurations.

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    Second: How To Prepare For The Coding Interview

    Now lets cut to the chase.

    How do you prepare for your coding interview?

    First, let me put you in the right mindset.

    If you try to google for generic job interview preparation questions, you will get the most useless answers.

    I did that for you and here is the first result at Google.

    Rest assured your interviewer will never ask you these questions.

    Even if your interviewer asks you one of these lame questions, its probably because he/she ran out of intelligent questions to ask.

    I can also assure you that your answers to these types of questions will have zero impact on the hiring decision.

    So dont waste your time trying to prepare for an intelligent answer to what your weaknesses are especially if you dont have any

    Here is the thing.

    Your coding interview is a technical interview.

    Your interviewers care mostly about how technically sound you are.

    They care about how competent and fast you are at solving problems.

    So my advice to you is to spend your valuable preparation time focussing mainly and mostly on the technical aspects of the interview because this is what really matters.

    With that said, here are the technical questions that you can expect in your coding interviews.

    Tip : Read Discussions On Blind

    Blind is an app for anonymous communication between professionals around the world, including software developers. It’s a community of almost 3 million experts that share industry-specific advice and their honest feedback about the companies they work at – their salaries, interview process, promotions, and perks. Many of them work for FAANG and other industry giants. Everything is anonymous, so if you’re seeking professional advice regarding the coding challenges, this app is a good source of information. You can even find information on the level of complexity, the time allocated, and the number of tasks – that other candidates are welcome to share.

    A coding challenge helps employers select the best candidates for the next stage. Also called the ‘zero stage’ of the interview, a coding challenge is a quick and easy way to see if the candidate is the right fit from the start. The coding challenges will help evaluate both coding techniques and engineering capabilities . So go ahead and check the discussions on Blind.

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    What Do You Understand By Object Cloning And How Do You Achieve It In Java

    • It is the process of creating an exact copy of any object. In order to support this, a java class has to implement the Cloneable interface of java.lang package and override the clone method provided by the Object class the syntax of which is:
    protected Object clonethrows CloneNotSupportedException
    • In case the Cloneable interface is not implemented and just the method is overridden, it results in CloneNotSupportedException in Java.

    What Concepts Are Emphasized During A Coding Interview

    30 java coding interview questions to crack any interview ...

    Concepts frequently emphasized include arrays and strings, binary trees, dynamic programming, and linked lists. According to CoderPad, other common interview topics include breadth-first search algorithms, palindrome checker, and sorted lists of numbers. Interviewers may emphasize data structures and algorithms.

    Common data structures tested include arrays, linked lists, stacks, and queues. Common algorithms tested include recursion, bubble sort, insertion sort, and binary search.

    Of course, the interview topics will also depend on the role you are interviewing for and the skills and tools that will likely be needed for the job.

    In addition to assessing your technical skills, the interviewer will also be watching for examples of creative thinking and the ability to receive and apply feedback. They may look for signs that tell them how you may fit in with the team and company culture, and judge your understanding of the role and the company’s work.

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    Landing A Job As A Java Developer

    Although some new programmers might question Javas relevance in todays tech world, its an incredibly popular choice for coders looking to work as a developer. There are more than nine million Java developers worldwide, and more than three billion smart phones run on Java today. The recent success of Java8 is a promising indication that the language will dominate the software development landscape for years to come.

    Hiring managers will tell a student that Java is one of the most in-demand skills they can learn. The question is how can students best prepare for the notoriously difficult interview questions when trying to land their first job?

    Going in, students should know that they can be questioned on any version of Java to date, and that many developer job interviews are conducted at least partially in writing. This means the interviewee will be expected to perform the answer on a whiteboard or on paper.

    Here is an example of how part of an interview might go, and suggested answers:

    Q: Describe what all the different parts of the main method declaration mean, and describe what each does.

    Q: What is the main difference in fail-fast and fail-safe iterators?

    A: Whether the collection can be modified while its being iterated. Fail-fast iterators do not allow this and fail-safe iterators do.

    Q: Why is it more secure to store sensitive data in a character array over a String?

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