Gain A Decent Knowledge Of Core Cs Subjects
Moving forward, the fundamentals and core concepts of important CS subjects particularly Operating Systems, Database Management System, and Computer Networks must be clear to you. These core subjects hold a considerable weightage in the tech interviews and the interviewers usually ask several questions from these subjects, especially from the fresher candidates whove just passed out of college or are in their final year. Though, as a fresher, youre not required to dive deep down into these core subjects all you need to have is a clear understanding of their basic concepts. For example: in the case of Operating Systems, you need to know about Process Management, I/O Management, Threads and Concurrency, Memory Management, etc. Similarly, when it comes to DBMS, youre required to go through relational and non-relational databases, ACID property, normalization, etc. Also, if youre having a considerable amount of work experience, you can opt to explore and learn System Design concepts such as Load Balancing, Caching & Proxies, CAP Theorem, Sharding, etc. while preparing for tech interviews.
Q8 What Is Method Overloading And Method Overriding
Method Overloading :
- In Method Overloading, Methods of the same class shares the same name but each method must have a different number of parameters or parameters having different types and order.
- Method Overloading is to add or extend more to the methods behavior.
- It is a compile-time polymorphism.
- The methods must have a different signature.
- It may or may not need inheritance in Method Overloading.
Lets take a look at the example below to understand it better.
class Adder Static double addpublic static void main}
- In Method Overriding, the subclass has the same method with the same name and exactly the same number and type of parameters and same return type as a superclass.
- Method Overriding is to Change existing behavior of the method.
- It is a run time polymorphism.
- The methods must have the same signature.
- It always requires inheritance in Method Overriding.
Lets take a look at the example below to understand it better.
class Car Class Audi extends Carpublic static void main}
Q8 What Purpose Do The Keywords Final Finally And Finalize Fulfill
Final is used to apply restrictions on class, method, and variable. A final class cant be inherited, final method cant be overridden and final variable value cant be changed. Lets take a look at the example below to understand it better.
Finally is used to place important code, it will be executed whether the exception is handled or not. Lets take a look at the example below to understand it better.
class FinallyExample catch finally }}}
Finalize is used to perform clean up processing just before the object is garbage collected. Lets take a look at the example below to understand it better.
class FinalizeExample public static void main}
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How To Completely Prepare For Tech Interviews
- Difficulty Level :Basic
A majority of college students hold a vision of getting into their dream company after completing their graduation. And why only college students, even many working professionals want to get rid out of their current job and get into their dream job or company eagerly.
Butwhat comes between these individuals and their dream job?? Okay, it is the INTERVIEW PROCESS!
Yes, to secure the desired job in your targeted company like Amazon, Microsoft, Swiggy, etc. youre first required to crack their multiple interview rounds. And to prepare for these tech interviews is not an easy-to-go task, especially for the freshers who often come across numerous problems such as what to prepare, where to prepare, etc.
However, things are not that difficult too as it seems. One can conveniently prepare for the tech interviews, whether it be of a startup or an IT giant if he follows the right preparation roadmap and strategies with sheer determination and consistency. Here, in this article, well get to know what skills you need to learn or what things you need to do, to crack the interview of any big tech company. Lets get started:
Follow These Tips To Impress The Interviewer And Ace The Coding Challenge
Whether youre a recent bootcamp grad or youve just finished up your computer science degree, youll likely have to go through a technical interview to land your first job. These interviews are unlike any other job interview and are meant to test your coding knowledge, problem-solving abilities, and personality. It can often feel like a daunting process, especially if its your first one. To get you through it, heres a guide with some tips and suggestions.
What Is The Difference Between The Program And The Process
- A program can be defined as a line of code written in order to accomplish a particular task. Whereas the process can be defined as the programs which are under execution.
- A program doesn’t execute directly by the CPU. First, the resources are allocated to the program and when it is ready for execution then it is a process.
Write A Java Program To Create And Throw Custom Exceptions
classInterviewBit}//Creating Custom Exception ClassclassCustomExceptionextendsException}
We have created the exception class named with CustomException and called the base exception constructor with the error message that we want to print. And to avoid handling exceptions in the main method, we have used the throws keyword in the method declaration.
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Q5 Explain The Role Of Dispatcherservlet And Contextloaderlistener
DispatcherServlet is basically the front controller in the Spring MVC application as it loads the spring bean configuration file and initializes all the beans that have been configured. If annotations are enabled, it also scans the packages to configure any bean annotated with @Component, @Controller, @Repository or @Service annotations.
ContextLoaderListener, on the other hand, is the listener to start up and shut down the WebApplicationContext in Spring root. Some of its important functions includes tying up the lifecycle of Application Context to the lifecycle of the ServletContext and automating the creation of ApplicationContext.
How Does An Exception Propagate In The Code
When an exception occurs, first it searches to locate the matching catch block. In case, the matching catch block is located, then that block would be executed. Else, the exception propagates through the method call stack and goes into the caller method where the process of matching the catch block is performed. This propagation happens until the matching catch block is found. If the match is not found, then the program gets terminated in the main method.
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Consider The Below Program Identify The Output And Also State The Reason For That
The output of the above program will be Hello. Main Method. This is because JVM will always call the main method based on the definition it already has. Doesn’t matter how many main methods we overload it will only execute one main method based on its declaration in JVM.
What Is Jdbc Connection Interface
The Connection interface maintains a session with the database. It can be used for transaction management. It provides factory methods that returns the instance of Statement, PreparedStatement, CallableStatement and DatabaseMetaData.
In case you are facing any challenges with these java interview questions, please comment on your problems in the section below.
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Question : Although Inheritance Is A Popular Oops Concept It Is Less Advantageous Than Composition Explain
Inheritance may be more popular but it still comes with certain limitations compared to composition. For instance, classes in Java can only come from one superclass which limits what a certain class can inherit.
Since composition is loosely coupled, its also easier to test functionalities and be more flexible with your code as opposed to inheritance.
What Are The Differences Between Constructor And Method Of A Class In Java
|Constructor is used for initializing the object state.
|Method is used for exposing the object’s behavior.
|Constructor has no return type.
|Method should have a return type. Even if it does not return anything, return type is void.
|Constructor gets invoked implicitly.
|Method has to be invoked on the object explicitly.
|If the constructor is not defined, then a default constructor is provided by the java compiler.
|If a method is not defined, then the compiler does not provide it.
|The constructor name should be equal to the class name.
|The name of the method can have any name or have a class name too.
|A constructor cannot be marked as final because whenever a class is inherited, the constructors are not inherited. Hence, marking it final doesn’t make sense. Java throws compilation error saying – modifier final not allowed here
|A method can be defined as final but it cannot be overridden in its subclasses.
|Final variable instantiations are possible inside a constructor and the scope of this applies to the whole class and its objects.
|A final variable if initialised inside a method ensures that the variable cant be changed only within the scope of that method.
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Write A Java Program To Reverse A String
classInterviewBit//Printing the reversed String. System.out.println) }}
In the above code, we are storing the last character from the string to the first and the first value to the last in the output character array. And doing the same thing in the loop for the remaining 2nd to n-1 characters. This is how the string will be reversed.
Prepare For Specific Interview Rounds
Youll often go through several rounds of interviews, from behavioral interviews to coding interviews, up to system design interviews.
Java coding interviews
Youll want to practice answering various interview questions.Since you have limited time to prepare, its important to have a strategic coding interview prep plan. In addition, you need to plan for what to do if youre given a coding problem you cant solve .
Here are some resources to help you prepare:
- Top 5 distributed system design patterns: Blog post covering design patterns including sharded services
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Why Do Companies Use Technical Assessment Platforms
In the United States, the cost in terms of lost engineering productivity for bringing each candidate onsite for a technical interview is about $1,500. Bringing unqualified candidates onsite can be cost-prohibitive and harmful to fast-paced, growing companies. For recruiters who otherwise have no way to effectively qualify candidates, technical assessment platforms offer a scalable and efficient alternative. Companies use Coderbyte throughout the hiring process to save $1,500 per engineering hire and more than $20,000 per year compared to other platforms.
How To Prepare For The Java Job Interviews
Right preparation will empower you to choose from multiple job offers & negotiate better rates. Expand your horizons into contracting/freelancing with the confidence that you can continuously find work in any job market with the sought-after high paying skills.
Just before attending a Java job interview
1. Firstly, reflect back on your past experiences and achievements by going through your resume to sell yourself more effectively. Think of situations where you have
Brush up on the Ice Breaker Interview Q& As to jog your memory and then follow the steps outlined below:
2. Secondly, understand your prospective employers requirements and correlate the requirements to your experiences and achievements so that you can convince your prospective employer as to how you can add value.
Carefully inspect the job description, and adapt your answers. The mentioning of your accomplishments & involvements in the 16 technical key areas are vital to set you apart from your competition. I am yet to work for an organization that did not face challenges relating to the technical key areas like design, performance, scalability, security, memory management, concurrency, etc, hence you can up-sell them in any Java job interviews.
What are these 16 technical key areas?
Most interviewers like to quiz you on design, performance, SDLC, concurrency, memory management, and security.
Full stack Java/JEE technologies are very vast
Java/JEE concepts, frameworks, and key areas
Another good question is:
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Write A Java Program To Rotate Arrays 90 Degree Clockwise By Taking Matrices From User Input
mport java.util.Scanner publicclassInterviewBit } System.out.print for System.out.println } System.out.println //Rotation//Transposefor }//Reverse Each rowfor } System.out.println for System.out.println } }}
In the above code, for rotating the matrix to 90 degrees we are first transposing the matrix so the row becomes the column. And after that, we are reversing each row in the matrix. So this is how the matrix got rotated.
More Java Interview Tips/advice
As with any job interview, the technical questions are only part of the fun. You will also be asked fit and resume questions to determine if youre a good match for the company and dig deeper into your job experience.
Do your best to learn something about the company and position beforehand. They shouldnt be the only people asking questions in the interview. It may seem obvious, but make sure youll be a good fit with them, too. Are you more blue jeans and a t-shirt person?
While that might be more casual than most environments, you wont do well with a company wearing suits and ties every day. Do you prefer to sit in your cube coding with your headphones on? You wont do well with a company that requires lots of interaction with customers. If you dont ask, youll never know.
Be prepared to ask at least some questions of the interviewer. Try not to rely on the obvious questions like how long theyve been at the company and dont go with a presumptuous question like, When can I start?
Its okay to ask the same question of all interviewers if you think youll get a different answer from each. A better question here might be What is a typical workday like? A bad question here is How does your company/team do testing?
A final thing to mention that might seem obvious, but is rarely if ever brought up during the interview: If an interviewer asks you to do the same coding problem that you addressed with an earlier interviewer, tell them.
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Q8 What Are The Different Methods Of Session Management In Servlets
Session is a conversational state between client and server and it can consists of multiple request and response between client and server. Since HTTP and Web Server both are stateless, the only way to maintain a session is when some unique information about the session is passed between server and client in every request and response.
Some of the common ways of session management in servlets are:
- SQLException etc.
What Are The Possible Ways Of Making Object Eligible For Garbage Collection In Java
First Approach: Set the object references to null once the object creation purpose is served.
Second Approach: Point the reference variable to another object. Doing this, the object which the reference variable was referencing before becomes eligible for GC.
Third Approach: Island of Isolation Approach: When 2 reference variables pointing to instances of the same class, and these variables refer to only each other and the objects pointed by these 2 variables don’t have any other references, then it is said to have formed an Island of Isolation and these 2 objects are eligible for GC.
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Practice Algorithms And Data Structures
Its rare that youll know what youre going to be tested on beforehand. Therefore, its imperative that you stay sharp and practice as much as you can. Theres plenty of great resources out there. To get you started you can check out LeetCode and AlgoExpert. Both of these websites allow you to work through common variations of problems asked by top-tier companies.
Dont get discouraged by the more difficult questions. If this is your first technical interview, you should only be expected complete easy to medium questions.
Why Is The Character Array Preferred Over String For Storing Confidential Information
In Java, a string is basically immutable i.e. it cannot be modified. After its declaration, it continues to stay in the string pool as long as it is not removed in the form of garbage. In other words, a string resides in the heap section of the memory for an unregulated and unspecified time interval after string value processing is executed.
As a result, vital information can be stolen for pursuing harmful activities by hackers if a memory dump is illegally accessed by them. Such risks can be eliminated by using mutable objects or structures like character arrays for storing any variable. After the work of the character array variable is done, the variable can be configured to blank at the same instant. Consequently, it helps in saving heap memory and also gives no chance to the hackers to extract vital data.
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Spring Interview Questions And Answers
Spring Framework is the most widely used Java EE framework. Its built on core principles of Dependency Injection and Aspect-Oriented Programming. This post contains more than 45 questions related to Spring Framework. They also cover Dependency Injection, Spring AOP, Spring JDBC, and Spring MVC.
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.
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Looking for interview tips? In 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.
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 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 examples of Java coding interview questions and answers to help you prepare.
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