Interview Questions and Answers for 'At' | Search Interview Question

Interview Questions and Answers - Order By Newest

Q241. What are some different logging levels for log4j ?

Log4j

Ans. DEBUG
ERROR
ALL
WARN
INFO
FATAL
OFF
TRACE
TRACE_INT
WARN

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java log4j log4j level logging error logging Asked in 10 Companies}

Q242. What are some differences between Spring caching and Hibernate caching?

Hibernate

Ans. Spring caching makes use of its intercepting capabilities to add caching to method calls. Therefore, the entire object is cached and reused. Hibernate, on the other hand, has more domain-specific knowledge of the Entity being cached and can handle the objects more appropriately.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve spring framework hibernate spring cache hibernate cache}

Q243. Difference between Stack and Heap memory ?

Core Java

Ans. Stack memory areas is used to hold method and local variables while objects are always allocated memory in the heap. The heap memory is shared between multiple threads whereas Stack memory isn't.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java memory management stack memory heap memory difference between ebay Asked in 2 Companies intermediate frequent}

Try 1 Question(s) Test

Q244. How to access a Web Element if there are many elements with the same XPath ?

Ans. By specifying the Index like

//button[@class='button'])[2]

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve selenium selenium webdriver automation testing}

Q245. Which of the following cannot be marked static ?

a. Constructors , Classes ( Outer ) , Classes ( nested ), Interfaces , Local variables , Inner Class methods and instance variables.
b. Constructors , Classes ( Outer ) , Interfaces , Local variables , Class variables , Class Methods , Inner Class methods and instance variables.
c. Constructors , Classes ( Outer ) , Interfaces , Local variables , Inner Class methods and instance variables.
d. Constructors , Classes ( Outer ) , Classes (Nested), Interfaces , Local variables , Inner Class methods and instance variables

Ans. Constructors , Classes ( Outer ) , Interfaces , Local variables , Inner Class methods and instance variables.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve oops java static nested classes static nested classes}

Try 2 Question(s) Test

Q246. How are values passed in Java ? By value or reference ?

Core Java

Ans. Java only provides pass by value.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve ebay pass by value pass by reference method call methods functions function call Asked in 10 Companies basic frequent}

Recently asked in Capital One.

Q247. What will happen if we call perform(null) ?

public void perform(Object obj) {
System.out.println("Object");
}

public void perform(Integer int) {
System.out.println("Integer");
}

Core Java

Ans. compiler will throws error as ambiguous methods

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve overloading method overloading Asked in 1 Companies intermediate}

Q248. What is a Database Trigger ?

Database

Ans. A trigger is a special kind of stored procedure that automatically gets executed upon an event in the database server.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve database trigger Asked in 10 Companies basic frequent}

Q249. Have you heard about the external table feature of Oracle ?

Database

Ans. The external tables feature is a complement to existing SQL Loader functionality. It enables to access data in external sources as if it were in a table in the database. We have used it few times for replicating tables across different database systems.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve external table oracle Asked in 1 Companies rare}

Q250. What is the use of Deprecated annotation ?

Ans. Deprecated annotation is for documentation purpose only. It doesn't enforce anything but would mark the method name as crossed to signify that the client should refrain from using it.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve Deprecated annotation}

Q251. Does Deprecated annotation enforces anything ?

Ans. No. It just marks the method and hence signals the client to refrain from using it.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve Deprecated annotation}

Q252. What is a self Join and give an example of a self Join ?

or

What is self Join and What is it's purpose ?

Database

Ans. When a Table Join itself , it's a Self Join. For example - we like to know the pair of department names where first dept has lesser employees than the later.

Select D1.name , D2.name from Dept D1, Dept D2 where D1.employee_count < D2.employee_count

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve sql joins self join self-join Pair of employee names with first having lesser salary than later Pair of department names where first dept has lesser employees than the later Asked in 26 Companies basic frequent}

Q253. What was the driving force to introduce default methods in Interfaces wef from Java 8 ?

Core Java

Ans. Earlier any class implementing an interface was supposed to implement all methods declared in an interface. There was no place for optionally implementing all or subset of methods.Though we have abstract classes wherein we could have provided such a mechanism by declaring some methods as abstract while providing definition for some. But as Abstract classes have a body and are comparatively heavier than interfaces and interfaces associate closely to the concept of providing interfacing than abstract classes, Java might have though of providing optional implementation for default methods. This way same interface can be reused in variety of ways rather than making copies of an interface to suit different needs.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java 8 java8 interface default methods default methods Asked in 6 Companies}

Q254. What are design situations to use Singleton and Prototype Design Pattern ?

Design

Ans. Both are creational design patterns.

Singleton is used when we would like to reuse an object if object is not supposed to hold request or thread specific information. Inversely Prototype is used in situations where we would like to reuse the object information but the request / thread may require it own data to be persisted.

In short, Singleton is used in situations where we can live with single object being shared across multiple requests or threads whereas Prototype is used when we need duplicate copies of objects.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve design pattern singleton prototype creational design pattrn Asked in 7 Companies expert}

Try 1 Question(s) Test

Q255. What are the advantages and disadvantages of Factory Design Pattern ?

Design

Ans. Object Oriented Design Patterns is the science of identifying the pattern to make objects communicate in a way to effectively implement a Solution.

Factory Design Patterns is the pattern that recommends creation of separate Factory Object for creation of other object. So its like saying - If you want to create an object of ClassA, Talk to FactoryObject ( which is an object of FactoryClass ). FactoryObject in itself encapsulates the inputs and logic required to make the decision regarding the creation and construction of object.

Advantage of Factory Pattern - Loose Coupling and Segregation of Responsibilities. Now instead of hard binding the complete logic to decide the nature and shape of the object on the basis of some conditions, you are assigning the responsibility to some other object and hence making the relationship loosely coupled and hence main tenable.

Disadvantages - Before Understanding the Dis-advantages , we should understand that these patterns were chosen after a period of evolution and research and almost best fit for the required solution, otherwise these patterns would have easily been replaced by now.

Though the advantages of these pattern surpass the disadvantages keeping in mind the decreasing cost of resources and increasing scale of applications, but still loose coupling by means of additional objects results in decreased performance.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve factory design pattern design pattern}

Q256. How do you prefer to store money values in your application ?

Core Java

Ans. At Application level we use either Double or BigDecimal , preferably BigDecimal. At Database level we use Number with decimal precision 3.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve data types}

Very Frequently asked to Senior Software Engineers or Developers.

Q257. Describe some of the Design Patterns you have used ?

Design

Ans. [Open Ended Answer]

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve design patterns Asked in 17 Companies intermediate frequent}

Q258. If everything is an object , Cant we declare every object as

Object obj = new String();

Core Java

Ans. Yes, we can do that. Compiler wont complain. But using object reference we can only access methods which have been defined for object class i.e clone(), equals(), hashCode(), toString() etc.

We cannot access methods defined in String class or in any class in hierarchy between String and Object.

For example - we cannot do obj.append("abc") as it will now give compile time error.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve object initialization object declaration runtime polymorphism object oriented programming (oops) oops concepts}

Q259. Which type of memory is cleaned / recovered by garbage collection - stack or heap ?

Core Java

Ans. Heap memory.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve memory management stack heap garbage collection Asked in 2 Companies}

Q260. What is the difference between for and foreach loop in java ? Which one should be used in which cases ?

Core Java

Ans. 1. for loop in java is used with a counter as following

for(int counter=0;counter < 50;counter++){
System.out.println(list.get(counter));
}

for iterating and printing the contents of a collection

whereas foreach loop can be specified directly without the use of counter

for(String str:list){
System.out.println(list.get(counter));
}

2. for Each loop syntax is more clean if we have to iterate over the elements of a collection and we need not keep track of the record count

3. For is preferred when we need loops without the usage of collections or Array of objects and entirely primitives are being used

4. for loop is preferred if we need to keep track of record count and have to perform some action of the basis of that. For example - If we have to print something after every 5 records, With for each loop in such case, we will have to keep a separate counter.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve loop for loop control statements loop statement foreach loop for vs foreach loop}

Q261. Does java supports operator overloading ?

Core Java

Ans. No

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve operator overloading Asked in 1 Companies basic}

Q262. What is database Normalization ?

Database

Ans. https://en.wikipedia.org/wiki/Database_normalization

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve normalization database Asked in 35 Companies intermediate frequent}

Q263. When is the situation when finally section won't execute ?

Core Java

Ans. If the process / app is abruptly killed or terminated.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve exception handling finally Asked in 2 Companies intermediate}

Try 1 Question(s) Test

Q264. What is the use of static keyword in Java ?

Core Java

Ans. static keyword is used to specify that the respective programming construct ( method , variable ) belongs to the class and not to its instance and is supposed to be shared by all instances of the class.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve static keyword Asked in 1 Companies basic frequent}

Q265. What is the difference between authentication and authorization ?

Authentication

Ans. Authentication is the process of verifying the identity and credentials of the user to authenticate him into the system.

whereas

Authorization is the process by which access to a segment , method or resource is determined.

Authorization is usually a step next to authentication.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve authentication authorization authentication vs authorization Asked in 9 Companies basic frequent}

Q266. Write a Program to print factorial of a number using recursion

Core Java

Ans. public class BuggyBread {
public static void main(String args[]) {
System.out.println(factorial(5));
}

private static int factorial(int number){
if(number == 1){
return 1;
} else {
return number * factorial(number - 1);
}
}
}

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve recursion Asked in 25 Companies}

Q267. What is Amazon S3 ?

Amazon Web Services (AWS)

Ans. Amazon Simple Storage Service or S3 is object storage with a simple web service interface to store and retrieve any amount of data from anywhere on the web.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve aws amazon s3 aws s3 aws storage amazon cloud storage amazon s3 Asked in 12 Companies}

Q268. Do you like Native SQL Apis like JDBC or JPA / Hibernate ?

Hibernate

^{This question is still unanswered. Can you please provide an answer.}

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve JDBC vs JPA JDBC vs Hibernate}

Q269. Difference between Virtual Memory and Demand Paging?

Operating System

^{This question was recently asked at 'Veritas'.This question is still unanswered. Can you please provide an answer.}

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve Virtual Memory vs Demand Paging Asked in 1 Companies}

Q270. Why it's a good practice to expose member elements through getter methods ?

Design

Ans. Encapsulation and Polymorphism.

We need methods to access variables in a polymorphic way as overriding only happens with methods and not with variables. Moreover getter provides a way to minimally open the access window for the object and hence provides better encapsulation. To add to those, we can have validation in the getter method before returning elements.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve encapsulation}

Search Interview Questions

Help us and Others Improve. Please let us know the questions asked in any of your previous interview.