Interview Questions and Answers - Basic Level | Search Interview Question

Interview Questions and Answers - Order By Newest

Q161. What is the difference between int[] x; and int x[]; ?

Core Java

Ans. No Difference. Both are the acceptable ways to declare an array.

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

_{Like Discuss Correct / Improve java array arrays array declaration difference between Asked in 3 Companies basic}

Q162. How can we protect an application from throwing a NullPointerException ?

Ans. By having Null Checks.

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

_{Like Discuss Correct / Improve exceptions npe nullpointerexception null checks basic frequent}

Q163. Why is a constant defined as a static final in Java?

Core Java

Ans. Final makes sure that the value doesn't change after initialization and static makes sure that there is only one copy that can be shared across objects.

Making it non static will unnecessarily create a different copy per object wherein the same value will kept for all copies ( as its final and cannot be changed ).

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

_{Like Discuss Correct / Improve java static final variables variable constants basic frequent}

Q164. What is Criteria in Hibernate ?

Hibernate

Ans. Criteria is a simplified API for retrieving entities by composing Criterion objects.

For example - session.createCriteria(Employee.class).add( Restrictions.like("name", "A%") ).list();

will return all employee objects having name starting with A.

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

_{Like Discuss Correct / Improve hibernate hibernate criteria Asked in 7 Companies Basic Frequent}

Try 1 Question(s) Test

Q165. What is Jenkins ?

Jenkins

Ans. It is a continuous integration tool written in Java.

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

_{Like Discuss Correct / Improve java jenkins Asked in 6 Companies Basic frequent}

Q166. Which takes more memory - float or Float ?

Core Java

Ans. float is a native data type whereas Float is a class. A Float object will always take more memory than float variable as there are metadata overheads with the objects.

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

_{Like Discuss Correct / Improve java data type float Asked in 3 Companies basic frequent}

Q167. Which of the collections allows null as the key ?

a. HashTable
b. HashMap
c. TreeMap
d. LinkedHashMap

Core Java

Ans. HashMap

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

_{Like Discuss Correct / Improve java collections map hashtable Asked in 2 Companies basic frequent}

Q168. Difference between prefix and postfix increment operator ?

Ans. Prefix operator performs the increment and then assignment whereas its inverse for postfix operator.

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

_{Like Discuss Correct / Improve prefix increment operator postfix increment operator operators java basic frequent}

Q169. Have you ever had any conflict with the team member (like disagreement on some design decision ) and How you reacted to it ?

General

Ans. [Open Ended Answer]

This is a very sensitive question and should be dealt with caution. Just simply saying that you never had any disagreement will present you as dumb team member. Showing your self as too aggressive in such decisions will present you as a trouble maker. You should present a situation where you had an argument / disagreement but eventually you and your team mates mutually found a way out of it.

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

_{Like Discuss Correct / Improve Asked in 20 Companies basic}

Frequently asked in face to face interviews.

Q170. Write a program to print fibonacci series.

Core Java

Ans. int count = 15;
int[] fibonacci = new int[count];
fibonacci[0] = 0;
fibonacci[1] = 1;
for(int x=2; x < count; x++){
fibonacci[x] = fibonacci[x-1] + fibonacci[x-2];
}

for(int x=0; x< count; x++){
System.out.print(fibonacci[x] + " ");
}

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

_{Like Discuss Correct / Improve ebay fibonacci series Asked in 66 Companies basic frequent}

Must know at all levels. Among Top 10 frequently asked questions in Java. Very frequently asked to fresh graduates or less experienced professionals.

Q171. What is Inheritance ?

Core Java

Ans. Its a facility for code reuse and independent extension wherein a derived class inherits the properties of parent class.

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

_{Like Discuss Correct / Improve inheritance object oriented programming (oops) oops concepts oops concepts java concepts code reuse code re-use classes derived classes Asked in 14 Companies basic frequent}

Q172. What is a Java Bean ? How is it different from other Java classes ?

Ans. A Java bean is a class which abides by following conventions:

Core of the object is member elements and not operations ( methods )

Member Elements can be accessed by getters (and setters if those properties are not read-only).

serializable.

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

_{Like Discuss Correct / Improve java bean javabean pojo classes basic frequent}

Q173. How is static and dynamic polymorphism achieved in Java ?

Core Java

Ans. Static polymorphism is the polymorphic resolution identified at compile time and is achieved through function overloading whereas dynamic polymorphism is the polymorphic resolution identified at runtime and is achieved through method overriding.

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

_{Like Discuss Correct / Improve static polymorphism object oriented programming (oops) oops concepts dynamic polymorphism object oriented programming (oops) oops concepts polymorphism object oriented programming (oops) oops concepts overloading overriding broadridg Asked in 1 Companies basic frequent}

Q174. Write a program / method to input few numbers and then print the sum.

Ans. http://javasearch.buggybread.com/CodeSnippets/searchCodeSamples.php?&category=code&searchOption&keyword=946

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

_{Like Discuss Correct / Improve code coding scanner basic}

Very frequently asked to fresh graduates. Frequently asked in NSEiT and Accenture India

Q175. Write a program to Generate prime numbers till a given number

Core Java

Ans. public class Main {
public static void main(String args[]) {
int number = 2;
int count = 0;
long sum = 0;
int givenNumber = 1000;
while (count < givenNumber) {
if (isPrimeNumber(number)) {
sum = number;
count;
}
number;
}
System.out.println(sum);
}
private static boolean isPrimeNumber(int number) {
for (int i = 2; i <= number / 2; i) {
if (number % i == 0) {
return false;
}
}
return true;
}
}

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

_{Like Discuss Correct / Improve generate prime numbers code coding Asked in 5 Companies basic frequent}

Q176. Write a program to calculate factorial of a number using recursion

Core Java

Ans.

public class Factorial {
   public static void main(String[] args){
      int x = 5;

      System.out.println(calculateFactorial(x));

   }

   private static int calculateFactorial(int x){
      if(x==1){
         return 1;
      }
      return x * calculateFactorial(x-1);
   }
}

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

_{Like Discuss Correct / Improve factorial calculate factorial code coding recursion Asked in 1 Companies basic}

Q177. Write code for constructor overloading

Core Java

Ans. http://javasearch.buggybread.com/CodeSnippets/searchCodeSamples.php?&category=code&searchOption&keyword=965

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

_{Like Discuss Correct / Improve constructor overloading code coding Asked in 2 Companies basic}

Q178. What is a Destructor ? Do we have Destructors in Java ?

Core Java

Ans. Destructor is used to de-allocate memory allocated by objects.

There are no destructors in Java. Alternatively, Java provides Automatic garbage collection i.e automatically releasing the un-referenced memory.

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

_{Like Discuss Correct / Improve destructor garbage collection Asked in 11 Companies Basic frequent}

Try 1 Question(s) Test

Frequently asked.

Q179. What should a class do if its implementing an interface ?

Core Java

Ans. It should either implement all interface methods or declare unimplemented methods as abstract.

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

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

Try 1 Question(s) Test

Q180. What should a class do if its extending an abstract class ?

Core Java

Ans. It should either implement the abstract methods or re-declare them abstract.

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

_{Like Discuss Correct / Improve abstract class Asked in 2 Companies Basic Frequent}

Q181. What are different types of variables in Java ?

Ans. 1. Function Local Variables
2. Instance Variables
3. Class variables or static variables

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

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

Frequently asked to Fresh graduates.

Q182. Write a program to implement Binary search ?

Core Java

Ans. http://algs4.cs.princeton.edu/11model/BinarySearch.java.html

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

_{Like Discuss Correct / Improve binary search search Asked in 5 Companies basic frequent}

Try 1 Question(s) Test

Q183. Which data structure would you recommend for ordered and sorted data?

Core Java

Ans. TreeSet and TreeMap are used for maintaining sorted elements.

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

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

Q184. What is a Database Procedure ?

Database

Ans. Stored procedures are a batch of SQL statements along with programming constructs ( if else, loops etc ) and stored as a single program that can be called by different clients and hence reused.

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

_{Like Discuss Correct / Improve database stored procedure Asked in 2 Companies basic frequent}

Very Frequently asked to fresh graduates and less experienced.

Q185. What are the principle concepts of Object Oriented Programming ?

Core Java

Ans. Abstraction Polymorphism Inheritance Encapsulation

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

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

Q186. What is an IP address ?

Java EE

Ans. An Internet Protocol address is a numerical label assigned to each device participating in a computer network.

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

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

All these acronyms JDK,JRE,JVM etc are very frequently asked.

Q187. Difference between JDK and JRE ?

Core Java

Ans. JRE or Java Runtime Environment is the Java Virtual Machine on which class files are executed. It includes borwser plugins that facilitates execution of class files in browsers.

JDK or Java Development Kit includes JRE , compiler and development tools.

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

_{Like Discuss Correct / Improve JDK JRE JDK vs JRE Difference between Asked in 4 Companies basic frequent}

Q188. What is CRUD ?

Database

Ans. CRUD stands for "Create, read, update and delete" are the basic functions of persistence.

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

_{Like Discuss Correct / Improve CRUD Persistence Database Database Operations Asked in 3 Companies Basic frequent}

Q189. What is DTO ?

Ans. DTO is Data Transfer Object i.e Pojo which is supposed to move between different layers of software architecture for transferring information. Example could be the object passed from client in case of web service call or the object passed to Persister for Database Persistence.

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

_{Like Discuss Correct / Improve DTO Data Transfer Object basic frequent}

Q190. What is DAO ?

Ans. DAO is Data Access Object which is used within Persistence Layer to make Database Transaction. For example , the class holding the Database connection and CRUD methods.

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

_{Like Discuss Correct / Improve DAO Data Access Object basic frequent}

Search Interview Questions

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