Interview Questions and Answers for 'Mp' | Search Interview Question - javasearch.buggybread.com

Javasearch.buggybread.com

Search Interview Questions

More than 3000 questions in repository.

There are more than 900 unanswered questions.
Click here and help us by providing the answer.

Have a video suggestion.
Click Correct / Improve and please let us know.

Submit Question

Interview Questions and Answers - Order By Rating

next 30

Q91. What is EC2 and EC2 instance ?

Amazon Web Services (AWS)

Ans. EC2 is elastics compute cloud is one of the amazon service and ec2 instance is one type of virtual server which you create from AMI.

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

_{Like Discuss Correct / Improve amazon ec2 aws ec2 aws computing amazon cloud computing amazon ec2}

Q92. What are the reasons to choose between reserved and on demand instances ?

Ans. In terms of compute options and configurations, Reserved Instances and On Demand instances are the same. The only difference between the two is that a Reserved Instance is one you rent (reserved) for a fixed duration, and in return you receive a discount on the base price of an On Demand instance.

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

_{Like Discuss Correct / Improve aws aws ec2 aws computing amazon cloud computing amazon ec2 production support Google Cloud Platform (GCP)}

Q93. What is cloud computing ?

Cloud Computing

Ans. Cloud Computing is a way of using IT infrastructure with following traits -

1. On Demand Infrastructure
2. Broad Network Access
3. Resource Pooling
4. Rapid Elasticity
5. Measured Service

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

_{Like Discuss Correct / Improve google cloud platform (GCP) Amazon Web Services (AWS}

Q94. How do you check memory leak in Java?

Ans. You need to capture heap dump when it's in the healthy state. Start your application. Let it take real traffic for 10 minutes. At this point, capture heap dump. Heap Dump is basically the snapshot of your memory. It contains all objects that are residing in the memory, values stored in those objects, inbound

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

_{Like Discuss Correct / Improve memory leaks heap dump Asked in 1 Companies intermediate}

Q95. Difference between JVM, JRE and JDK ?

Ans. JDK(Java Development kit) = Development Kit comprising of JVM , library and development tools for developers

JRE (Java Run time Environment) - Comprise of JVM and set of libraries

JVM(Java Virtual Machine) = Interpreter which reads the .class file line by line.

When we install JDK, JRE also get installed so we can write,compile and excute our code. Used by developer. Without JDK we can only execute the program using JRE.

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

_{Like Discuss Correct / Improve jvm jre jdk jvm vs jre vs jdk Asked in 4 Companies}

Q96. What is abstraction ?

Ans. Abstraction is a process of hiding the implementation details and describing only the functionality to the user.

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

_{Like Discuss Correct / Improve bstraction oops concepts oops principle Asked in 22 Companies}

Q97. How is LinkedList collection class internally implemented ? Is it a Linked List or Doubly Linked List ?

^{This question was recently asked at 'Ancestry'.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 linkedlist internal implementation of linkedlist Asked in 1 Companies}

Q98. Which components of AWS are you using in your project ?

Amazon Web Services (AWS)

Ans. We are using EC2 and Lambda for computing, RDS for Database , S3 for Storage , SQS and Kinesis for streaming and queue and CloudWatch for monitoring.

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

_{Like Discuss Correct / Improve aws aws components}

Q99. Which java package is loaded by default and hence doesn't require an explicit import statement ?

Ans. java.lang

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

_{Like Discuss Correct / Improve java.lang import statement basic}

Q100. What is the problem we could face if we be very liberal with importing classes even if we are not using them ? For example

import java.util.*;
import java.io.*;

Ans. It makes application little heavy as we are importing classes that aren't required.

It creates class name conflicts as similar name classes might be available across different packages. In case of such conflicts, we will have to specify the package name with the class name at the time of it's usage.

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

_{Like Discuss Correct / Improve import statement java import}

Q101. What does import java.util.* means in java ?

Ans. It means import all the classes and interfaces within java.util package and make them available to use within the current class or interface. This is shorthand wild card annotation for importing all classes within a particular package. This won't import the classes within the sub packages of java.util.

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

_{Like Discuss Correct / Improve java import import statement}

Q102. Can we compile and execute a Java class without main method ?

Ans. No without main method can not be executed it will throw an error illegal start of type. Main method is the entry point of application.

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

_{Like Discuss Correct / Improve jvm compilation main method Basic}

Q103. Give an example of how Object Oriented Programming Concepts can be implemented.

Ans. You can implement encapsulation in Java by keeping the fields (class variables) private and providing public getter and setter methods to each of them. Java Beans are examples of fully encapsulated classes. Encapsulation in Java: Restricts direct access to data members (fields) of a class.

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

_{Like Discuss Correct / Improve oops oops example oops concepts oops features Asked in 2 Companies basic frequent}

Q104. Explain OOPs

or

Explain OOPs Principles

or

Explain OOPs Concepts

or

Explain OOPs features

or

Tell me something about OOPs

Ans. OOPs or Object Oriented Programming is a Programming model which is organized around Objects instead of processes. Instead of a process calling series of processes, this model stresses on communication between objects. Objects that all self sustained, provide security by encapsulating it's members and providing abstracted interfaces over the functions it performs. OOP's facilitate the following features

1. Inheritance for Code Reuse
2. Abstraction for modularity, maintenance and agility
3. Encapsulation for security and protection
4. Polymorphism for flexibility and interfacing

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

_{Like Discuss Correct / Improve oops oops features Asked in 260 Companies basic frequent}

Q105. How would you explain the statement "Java Programs are collection of objects" ?

Ans. Java Programs are collection of objects that communicates with each other to get a task accomplished. To add to those objects, there are common spaces ( static i.e common for objects belonging to a class ) that are used too.

We can visualize objects as departments of an organization in real world. Just like Task gets initiated in one department and then files are moved across different departments to get work done. In a similar fashion, a task is initiated in one object ( having main method ) and then information ( through POJOs / DTOs ) is moved across objects to accomplish a task.

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

_{Like Discuss Correct / Improve objects Java Programs are collection of objects real life example of object communication}

Q106. What is the difference between Elastic Compute Cloud and Elastic Beanstalk ?

Amazon Web Services (AWS)

Ans. EC2 is Amazon computing service whereas Elastic Beanstalk is the AWS service for deploying and managing web applications.

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

_{Like Discuss Correct / Improve Elastic Compute Cloud EC2 Elastic Beanstalk}

Q107. What is Amazon EC2 ?

Amazon Web Services (AWS)

Ans. Amazon Elastic Compute Cloud or EC2 provides scalable computing capacity in the AWS cloud. It can be used to create Virtual Environments , storage and configure. EC2 enables to upgrade or downgrade infrastructure according to the rules defined ( with fluctuation in latency, traffic etc )

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

_{Like Discuss Correct / Improve aws aws ec2 aws computing amazon cloud computing amazon ec2 Elastic Compute Cloud Amazon Elastic Compute Cloud Asked in 2 Companies}

Q108. What is meant by the statement "Java is turing complete" ?

Ans. This means that Java can simulate any Turing machine, and thus, it can solve any problem that a Turing machine can, given enough time and resources

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

_{Like Discuss Correct / Improve turing complete}

Q109. Which of the following is valid greater than and equal to operator in Java ?

>=
=>

Ans. >=

=> will result in error.

=> somewhat looks like lambda operator "->"

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

_{Like Discuss Correct / Improve operators >= operator greater than and equal to operator comparison operators}

Q110. What are the different layers of cloud computing ?

Ans. Paas - Platform as a service
Iaas - Infrastructure as a service
Saas - Software as a service

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

_{Like Discuss Correct / Improve cloud computing Amazon Web Service (AWS) Google Cloud Platform (GCP)}

Q111. What will be result of following code and why

Integer int1 = 1;
Integer int2 = 1;
String str1 = new String("str");
String str2 = new String("str");
String str3 = "str";
String str4 = "str";

System.out.println(int1 == int2);
System.out.println(str1 == str2);
System.out.println(str3 == str4);

Ans. true
false
true

Just like Strings, java maintains an integer constant pool too. So 1 will be maintained in integer constant pool and hence reference int2 will point to same integer in pool.

String pool is only for string literals ( defined by "" ) and not for newly created objects and hence str1 == str2 will return false as they are separate objects in memory.

String pool is used for storing string literals so that they can be reused and str3 and str4 will point to same string literal in string pool.

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

_{Like Discuss Correct / Improve string pool integer constant pool string comparison integer comparison}

Q112. What is the importance of Abstract Class ?

Ans. Abstract classes provide a mechanism of interfacing ( using abstract method ) as well as code reuse through inheritance ( extending abstract class )

Comparing to concrete class they have an advantage of providing interface which a concrete class doesn't provide.

Comparing to interfaces they have an advantage of providing code reuse through inheritance which interfaces dont provide.

Sample Code for abstract class

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

_{Like Discuss Correct / Improve abstract class importance of abstract class Basic frequent}

Q113. Find the third last element in a linked list ?

Ans. First Find the number of nodes in the linked list and take it as n.then find the data at n-3 element.

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

_{Like Discuss Correct / Improve linkedlist Asked in 1 Companies}

Q114. Write a program for 0 and cross games?

^{This question was recently asked at 'Compro Technologies'.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 code.coding.0 and cross game Asked in 1 Companies}

Q115. Write a Program to merge two sorted arrays ?

Ans. We can merge two sorted array by using quick sort algorithm

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

_{Like Discuss Correct / Improve arrays merge sorted arrays Asked in 2 Companies}

Q116. Why do we need Garbage collection ?

Ans. Garbage collection mechanism frees up the memory that is no longer needed. In languages like C / C++ the deallocation needs to be done explicitly by the programmer and hence any leniency may result in memory leak. Garbage collection in java ensures that all unused memory is reclaimed and hence there are no memory leaks.Moreover it relieves the programmer from the hassle of carefully releasing all memory.

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

_{Like Discuss Correct / Improve Garbage Collection memory management Asked in 2 Companies}

Q117. Given 2 jars of 5 ltr and 3 ltr, how will you get 4 ltrs in one of those jars ?

Ans. Number 1 -

Fill the 5 litre can from the tap

Empty the 5 litre can into the 3 litre can leaving 2 litres in the 5 litre can.

Pour away the contents of the 3 litre can.Fill the 3 litre can with the 2 litres from the 5 litre can leaving 2 litres in the 3 litre can.

Fill the 5 litre can from the tap.Fill the remaining 1 litre space in the 3 litre can from the 5 litre can.Leaving 4 litres in the 5 litre can.

Number 2 -

Fill the 3 litre can from the tap.Empty the contents of the 3 litre can into the 5 litre can.

Fill the 3 litre can from the tap.Empty the contents of the 3 litre can into the 5 litre can leaving the 5 litre can full and 1 litre in the 3 litre can.

Pour away the contents of the 5 litre can. Pour the 1 litre from the 3 litre can into the 5 litre can.

Fill the 3 litre can from the tap. Empty the contents of the 3 litre can into the 5 litre can leaving 4 litres in the 5 litre can.

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

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

Q118. Difference between import and include directive in jsp

^{This question was recently asked at 'ADP'.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 JSP import and include directive in jsp Asked in 1 Companies}

Q119. Write program to create a linked list and perform different operations on it.

Ans. import java.util.*;
class LinkedListSolution{
protected LinkedList list;
public LinkedListSolution(){
list = new LinkedList();
}
public Object pop() throws NoSuchElementException{
if(list.isEmpty())
throw new NoSuchElementException();
else
return list.removeFirst();
}
public void push(Object obj){
list.addFirst(obj);
}
public Object peek() throws NoSuchElementException{
if(list.isEmpty())
throw new NoSuchElementException();
else
return list.getFirst();
}
public boolean isEmpty(){
return list.isEmpty();
}
public String toString(){
return list.toString();
}
}
class TestStack{
public static void main(String args[]){
LinkedListSolution s = new LinkedListSolution();
s.push("First");
s.push("Second");
s.push("Third");
System.out.println("Top: " s.peek());
s.push("Fourth");
while(!(s.isEmpty()))
System.out.println(s.pop());
}
}

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

_{Like Discuss Correct / Improve Linkedlist data structures algorithm Asked in 2 Companies basic}

Q120. What is an execution engine within JVM ?

Ans. Execution engine contains interpreter and JIT compiler, which covert byte code into machine code.

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

_{Like Discuss Correct / Improve jvm execution engine compiler Asked in 1 Companies}

previous 30

next 30