Interview Questions and Answers for 'T' | Search Interview Question

Interview Questions and Answers - Order By Newest

Q1201. Which method of String class is used to convert Boolean to String ?

Ans. toString() is an overloaded method of String class that is used to convert many data types to String, Boolean being one of them.

toString(Boolean bool)

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

_{Like Discuss Correct / Improve String String class Boolean Asked in 1 Companies Basic}

Q1202. What are Collection Classes ?

Core Java

Ans. Collections in java is a framework of classes that provides an abstracted data structure to store and manipulate the group of objects. Each class is unique in the way it stores , search , sort and modify the elements.

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

_{Like Discuss Correct / Improve collections collection classes Asked in 1 Companies Basic frequent}

Q1203. Write a Program to print the positive and negative numbers separetly

Core Java

Ans. int[] arr = {1,-1,2,-3,3,-4,4,5,6,-5,-6,-7,-8,8,9,-9};
List positiveNumbers = new ArrayList<>();
List negativeNumbers = new ArrayList<>();
for(int i = 0; i < arr.length(); i ){
if(I < 0){
negativeNumbers.add(i);
} else {
positiveNumbers.add(i);
}
}

System.out.println("Positive Numbers:" + positiveNumbers);
System.out.println("Negative Numbers:" + negativeNumbers);

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

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

Q1204. Explain some of the http status codes you know ?

Java EE

Ans. 500 is Internal Server Error

404 is resource not found

400 is Bad Request

403 is Forbidden

401 is Unauthorized

200 is OK

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

_{Like Discuss Correct / Improve http http status codes Asked in 2 Companies frequent}

Q1205. What is Spring Boot ?

Spring Boot

Ans. Spring Boot is Springs convention-over-configuration solution for creating stand-alone, production-grade Spring-based Applications.

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

_{Like Discuss Correct / Improve Spring Boot Asked in 7 Companies}

Q1206. What is Maven ?

Maven

Ans. Maven is a build automation tool used primarily for Java projects.

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

_{Like Discuss Correct / Improve maven build Asked in 6 Companies basic frequent}

Q1207. Difference between Maven and Ant ?

Maven

Ans. Ant is procedural, we need to provide information about what to do and when to do through code.

Maven is declarative, everything is defined in the pom file.

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

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

Q1208. What could be the problems due to the usage of static methods and elements ?

Core Java

Ans. static methods and static elements are shared by all objects of a class and hence could create problem.

Static methods are not synchronized by default and hence could create problem when accessed through multiple threads. Static elements are shareable by class and hence state of one object could be altered by another object.

Some limitations with Unit testing as not all mocking framework facilitate mocking them. Power mock allows but Mockito doesn't

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

_{Like Discuss Correct / Improve static static method static variables}

Q1209. What is the advantage of using static final or constant variables in Java ?

Core Java

Ans. Better Control - If the value is being used at multiple locations , that can be controlled better from single place. Any change would only require making single change.

Meaning , Aliasing and Better Readability - Sometimes its easy to read the value by its meaning or alias ( 0 as ZERO or 0 as NEUTRAL_VALUE ).

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

_{Like Discuss Correct / Improve static final final variable variable constants}

Q1210. What is serialVersionUID ?

Core Java

Ans. Everytime an object is serialized the java serialization mechanism automatically computes a hash value by passing the meta information for the class. This id is used during deserialization to verify that the sender and receiver of a serialized object have loaded classes for that object that are compatible with respect to serialization

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

_{Like Discuss Correct / Improve serialVersionUID serialization Asked in 3 Companies expert rare}

Q1211. With a Table employee having columns Id,Name,ManagerEmployeeId, Write a SQL to find the Manager with maximum number of employees ?

Database

Ans. Select Name from EMPLOYEE where ID in (Select ManagerEmployeeId from EMPLOYEE
Group By ManagerEmployeeId
order by count(Id)
LIMIT 1)

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

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

Q1212. How to make sure that only one instance is created in Singleton Pattern ?

Core Java

Ans. public class SingleTon {
private SingleTon() {
if (singleTon != null) {
throw new RuntimeException("cant not create the object");
}
}
public Object clone() throws CloneNotSupportedException {
throw new CloneNotSupportedException("can not be create");
}

static private volatile SingleTon singleTon;
public static SingleTon getInstance() {
SingleTon singleTon = this.sample;
if (singleTon == null) {
synchronized (this) {
singleTon = this.singleTon;
if (singleTon == null) {
singleTon = this.singleton = new SingleTon();
}
}
}
return singleTon;
}
}

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

_{Like Discuss Correct / Improve singleton design pattern Asked in 2 Companies}

Q1213. Can we have an entity in hibernate without primary Key ?

Hibernate

Ans. No, Every entity in hibernate needs to have a key, either primary or composite.

If we dont have a primary key on table, there are various ways this problem can be countered.

1. By using composite key on entity ( make sure that the appropriate unique constraint in defined on columns in Database )

2. By mapping Id in entity to ROWID of table.

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

_{Like Discuss Correct / Improve hibernate entity hibernate}

Q1214. Provide an implementation for Producer / Consumer using threads.

Core Java

Ans. https://www.tutorialspoint.com/javaexamples/thread_procon.htm

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

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

Q1215. When should we use Abstract classes ?

Core Java

Ans. Abstract classes provide a mechanism of interfacing ( using abstract method ) as well as inheritance ( extending abstract class ). So they should be used in place of interfaces in case there is some code ( methods ) or object body ( member elements ) that can be reused with inheritance.

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

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

Q1216. What is the difference between following code segments

1.

try {
for(int i=0;i<100;i++){
calculate(i);
}
} catch (Exception ex) {
System.out.println("Error while processing")
}

and

2.

for(int i=0;i<100;i++){
try {
calculate(i);
} catch (Exception ex) {
System.out.println("Error while processing")
}
}

Core Java

Ans. In first case the whole loop will terminate as soon as any exception happens in the method calculate ( assuming calculate method is not handling its exception and those are thrown back at the calling method )

In Second case exception will be caught for individual iteration and hence it wont break the loop and will continue for the next iteration.

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

_{Like Discuss Correct / Improve exception handling try catch Asked in 1 Companies}

Q1217. What is the difference between ServletConfig and ServletContext ?

Java EE

Ans. http://www.java4s.com/java-servlet-tutorials/difference-between-servletconfig-and-servletcontext-in-java/

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

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

Q1218. Explain some of the features of Java ?

Core Java

Ans. Object Oriented - Java is object oriented but isn't purely object oriented as we have primitives along with objects.

Platform Independent - As JVM provides the translation to the Machine code as per the underlying Operating System.

Interpreted as well as compiled - Java files are compiled as class files and then class files are interpreted by JVM.

Runs on a Virtual Machine - Which is JVM that acts as an independent sub environment.

Multi-threaded - As applications can run on single thread as well as multi thread.

Modularity - Through usage of Classes , methods and Interfaces.

Robust

Usage in variety of Application types - Web , Gaming, BigData.

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

_{Like Discuss Correct / Improve frequent}

Q1219. Name some of the Java Keywords ?

Core Java

Ans. Static , Final , Synchronized, private , public , protected, volatile, transient, super, this,import , abstract,native,default (effective java 8), new

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

_{Like Discuss Correct / Improve java keywords frequent}

Q1220. Which operators in Java have highest precedence ?

Core Java

Ans. Braces, i.e () and [] have the highest precedence

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

_{Like Discuss Correct / Improve java operators}

Q1221. Which class is the root class of all Exceptions in Java ?

Ans. Throwable

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

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

Q1222. What is MAC Address ?

Networking

Ans. A media access control address is a unique identifier assigned to network interfaces for communications at the data link layer of a network segment. MAC addresses are used as a network address for most IEEE 802 network technologies, including Ethernet and Wi-Fi.

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

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

Q1223. What is an exception and exception handling in Java ?

Core Java

Ans. An Exception in java is the occurrence during computation that is anomalous and is not expected.

Exception handling is the mechanism which is used to handle such situations.

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

_{Like Discuss Correct / Improve exception handling Asked in 18 Companies basic frequent}

Q1224. What technical stuff you like to do in your free time ?

General

Ans. [Open Ended Answer]

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

_{Like Discuss Correct / Improve Asked in 2 Companies frequent}

Q1225. What is a factory design pattern ?

Design

Ans. 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.

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

_{Like Discuss Correct / Improve design pattern factory design pattern Asked in 9 Companies}

Q1226. How is hashcode calculated in java ?

or

What are the rules for hashcode calculation ?

Core Java

Ans. General contract of hashCode is:

1.Whenever it is invoked on the same object more than once during an execution of a Java application, the hashCode method must consistently return the same integer,

2.If two objects are equal according to the equals(Object) method, then calling the hashCode method on each of the two objects must produce the same integer result.

3.It is not required that if two objects are unequal according to the equals(java.lang.Object) method, then calling the hashCode method on each of the two objects must produce distinct integer results.

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

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

Q1227. Why main method is declared static ?

Core Java

Ans. static is the keyword that makes it accessible even without creating any object and using class name only. Making it non static would like creation of object upfront before calling the method.

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

_{Like Discuss Correct / Improve main method static Asked in 4 Companies Basic}

Q1228. What is Spring Security ?

Spring

Ans. Spring Security is a powerful and highly customizable authentication and access control framework. It is the de facto standard for securing Spring-based applications.

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

_{Like Discuss Correct / Improve Asked in 3 Companies}

Q1229. Create a Class Bank with the methods to deposit and Withdraw ?

Core Java

Ans. class Bank {
int balance;

Bank(){
balance = 0;
}

void deposit(int amount){
balance = balance amount;
}

int withdraw(int amount){
balance = balance - amount;
return balance;
}
}

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

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

Frequently asked in high end product companies.

Q1230. Write code for LRU Cache

Core Java

Ans. https://www.geeksforgeeks.org/lru-cache-implementation/

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

_{Like Discuss Correct / Improve cache LRU cache coding code Asked in 10 Companies intermediate}

Search Interview Questions

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