Interview Questions and Answers - Order By Newest Q2161. Write a java program to find the maximum profit in day trading Core Java
This question was recently asked at 'Capital One'.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   Asked in 1 Companies Q2162. What are basic functions of OOPS ? Core Java
This question was recently asked at 'Zillious'.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   Asked in 1 Companies Q2163. Where to use interface and abstract class ? Core Java
This question was recently asked at 'Exterro,Equator Business Solutions'.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   Asked in 2 Companies Q2164. Can we mock static methods using Mockito ? PowerMock
Ans. No, We can use PowerMock for that. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  mockito Q2165. Does Java SE has Immutable collections ? Core Java
Ans. Yes wef from Java 9 Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java 9  java9  immutable  immutability collections Q2166. suppose i have interface and i have declare lots of abstract method in interface But in sub class only two methods are use .than how to use oly two methods. Design
This question was recently asked at 'oodless 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   Asked in 1 Companies Q2167. Can you write immutable class without final? Core Java
Ans. By making the constructor private Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Asked in 1 Companies Q2168. Is java fully platform independent ? Core Java
Ans. yes, Java is a class-based and object-oriented programming language. It is a platform-independent language i.e. the compiled code can be run on any java supporting platform. It runs on the logic of “Write once, run anywhere”. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Asked in 1 Companies Q2169. Which s/w is used for adhar card verification for amount transfer?
Ans. The Aadhaar enabled Payment System or AePS Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Asked in 1 Companies Q2170. Can we use try within catch block ? Core Java
Ans. Yes Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Asked in 1 Companies Q2171. What are the features of Spring Framework ? Spring
Ans. Core technologies: dependency injection, events, resources, i18n, validation, data binding, type conversion, SpEL, AOP.
Testing: mock objects, TestContext framework, Spring MVC Test, WebTestClient.
Data Access: transactions, DAO support, JDBC, ORM, Marshalling XML.
Spring MVC and Spring WebFlux web frameworks.
Integration: remoting, JMS, JCA, JMX, email, tasks, scheduling, cache.
Languages: Kotlin, Groovy, dynamic languages. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Asked in 2 Companies Q2172. Isnt the use of HashTable and ConcurrentHashMap the same, i.e providing synchronized map collection ? Core Java
Ans. Both provide the thread safety but the actual difference come when talk about performance. CHM gives best performance when no of writer threads are less in number. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  synchronized collections  hashtable  ConcurrentHashMap Asked in 1 Companies Q2173. Tell me about thread pool? Design
Ans. Java provides its own implementations of the thread pool pattern, through objects called executors. These can be used through executor interfaces or directly through thread pool implementations which does allow for finer-grained control. The java.util.concurrent package contains the following interfaces:
Executor : a simple interface for executing tasks.ExecutorService a more complex interface which contains additional methods for managing the tasks and the executor itself.
ScheduledExecutorService: extends ExecutorService with methods for scheduling the execution of a task.Alongside these interfaces, the package also provides the Executors helper class for obtaining executor instances, as well as implementations for these interfaces.
Generally, a Java thread pool is composed of:
The pool of worker threads, responsible for managing the threads.
A thread factory that is responsible for creating new threads.
A queue of tasks waiting to be executed. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  thread pool Asked in 1 Companies Q2174. What is the purpose of doing mvn eclipse:eclipse or man idea:idea Maven
Ans. It is an instruction to maven to set up files ( class path , project ) within the IDE Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  IDE  eclipse  intelliJ  Maven Q2175. Do you use Mockito's generic any method or just prefer to use specific arguments ? Mockito
Ans. It depends on the data type, we use as the parameter.
If it is a simple data type and we validate the input, we may use specific arguments.
Else, we can go for the generic any Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Q2176. Does it make sense to verify a method call if we already have a mock for it.
For example -
Mockito.when(a.callMethod()).thenReturn(1);
verify(a.callMethod()); // Does it make sense Mockito
Ans. There is no guarantee that the mock will get called as callMethod may never get called. Verify is to make sure that the method gets called. Mock is it return 1 if the method gets called so they both are kind of independent things. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Q2177. Will it print the message in Base Class constructor if we execute main method of Main class ? why ?
public class BaseClass {
BaseClass(){
System.out.println("Hello I am in Base Class Constructor");
}
}
public class DerivedClass extends BaseClass{
}
public class Main {
public static void main(String[] args) {
DerivedClass derivedClass = new DerivedClass();
}
} Core Java
Ans. Yes.
When the Derived class constructor is initialized , a no argument super will be called intrinsically. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  constructor Q2178. What will the following print upon executing main method of Main class ?
public class BaseClass {
BaseClass(){
System.out.println("Hello I am in Base Class Constructor");
}
}
public class DerivedClass extends BaseClass{
DerivedClass(){
System.out.println("Hello I am in Derived Class Constructor");
}
}
public class Main {
public static void main(String[] args) {
DerivedClass derivedClass = new DerivedClass();
}
} Core Java
Ans. Hello I am in Base Class Constructor
Hello I am in Derived Class Constructor Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  constructor Q2179. What will the following code print upon executing main method of Main class ?
public class BaseClass {
BaseClass(){
System.out.println("Hello I am in Base Class Constructor");
}
}
public class DerivedClass extends BaseClass{
DerivedClass(){
System.out.println("Hello I am in Derived Class Constructor");
super();
}
}
public class Main {
public static void main(String[] args) {
DerivedClass derivedClass = new DerivedClass();
}
}
Core Java
Ans. There will be compilation error within constructor of Derived Class as "super must be the first statement in constructor body". Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  constructor Q2180. What will the following code print upon executing main method of Main class ?
public class BaseClass {
BaseClass(int x){
System.out.println("Hello I am in Base Class Constructor");
}
}
public class DerivedClass extends BaseClass{
DerivedClass(){
System.out.println("Hello I am in Derived Class Constructor");
}
}
public class Main {
public static void main(String[] args) {
DerivedClass derivedClass = new DerivedClass();
}
} Core Java
Ans. Compilation error as there is no default constructor available in BaseClass. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  constructor Q2181. What will the following code print upon executing main method of Main class ?
public class BaseClass {
BaseClass(int x){
System.out.println("Hello I am in Base Class Constructor");
}
}
public class DerivedClass extends BaseClass{
DerivedClass(){
super(1);
System.out.println("Hello I am in Derived Class Constructor");
}
}
public class Main {
public static void main(String[] args) {
DerivedClass derivedClass = new DerivedClass();
}
} Core Java
Ans. Hello I am in Base Class Constructor
Hello I am in Derived Class Constructor Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  constructor Q2182. Why line 4 in this code gives error saying "Cannot be referenced from a static context" ?
public class OuterClass {
public static void main(String[] args){
InnerClass innerClass = new InnerClass();
}
class InnerClass {
}
} Core Java
Ans. InnerClass is a non static inner class and hence can only be instantiated using instance of the outer class. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  inner class Q2183. What will the following code print upon executing main method of Main class
public class BaseClass {
BaseClass(){
this(2);
System.out.println("Hello I am in Base Class Constructor");
}
BaseClass(int i){
System.out.println("Hello I am in Base Class int argument Constructor");
}
}
public class DerivedClass extends BaseClass{
DerivedClass(){
super(1);
System.out.println("Hello I am in Derived Class Constructor");
}
}
public class Main {
public static void main(String[] args) {
DerivedClass derivedClass = new DerivedClass();
}
} Core Java
Ans. Hello I am in Base Class int argument Constructor
Hello I am in Base Class Constructor
Hello I am in Derived Class Constructor Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  constructor Q2184. What will the following code print upon executing main method of Main class
public class BaseClass {
BaseClass(){
this(2);
System.out.println("Hello I am in Base Class Constructor");
}
BaseClass(int i){
System.out.println("Hello I am in Base Class int argument Constructor");
}
}
public class DerivedClass extends BaseClass{
DerivedClass(){
System.out.println("Hello I am in Derived Class Constructor");
}
}
public class Main {
public static void main(String[] args) {
DerivedClass derivedClass = new DerivedClass();
}
} Core Java
Ans. Hello I am in Base Class int argument Constructor
Hello I am in Base Class Constructor
Hello I am in Derived Class Constructor Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  constructor Q2185. Why string pool concept has been introduced in string ? Core Java
Ans. Memory Sharing and Optimal memory utilization. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  String Pool Asked in 1 Companies Q2186. Write a Program to Find the maximum sum of the sub array ? Data Structure
This question was recently asked at 'Reddit'.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  Maximum subarray variant  arrays  sub array  subarray Asked in 1 Companies Q2187. Explain In place sorting algorithm ? Algorithm
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This question was recently asked at 'Jagan Institute of Management Studies (JIMS)'.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   Asked in 1 Companies Q2189. What are the benefits of Junits ? Junit
This question was recently asked at 'Cognizant ( CTS )'.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   Asked in 1 Companies Ans. Hadoop 1.x
It supports only MapReduce (MR) processing model.
It has limited scaling of nodes. Limited to 4000 nodes per cluster.
It has single Namenode to manage the entire namespace.
It has Single-Point-of-Failure (SPOF)
Works on concepts of slots – slots can run either a Map task or a Reduce task
MR has to do both processing and cluster resource management.
Hadoop 2.x
It supports MR as well as other distributed computing models like Spark, Hama, etc
It has better scalability. Scalable up to 10000 nodes per cluster.
Works on concepts of containers. Using containers can run generic tasks.
It has Multiple Namenode servers manage multiple namespace.
YARN does cluster resource management and processing is done using different processing models. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve