Zensar Technologies Fullstack Java Developer Interview Questions and Answers

1)Driffience between Abstract class &
Interface.
-abstract class
represents property
&
behaviour of an object
whereas
interface
represents
behaviour
of an object.
2)Driffience between equal() vs ==operator.
equal() is
an object class method
whereas
equal() of string class
override
the object class equal().
3)can we use pointer's in Java.
Not explicitly but implicitly we can use pointer's in java.
Dynamic m/m refers with help of pointer's but java does not support the pointer's.
when we r creating an object in java refrence varaible of an object holds the identity that is nothing but an implicit pointer that holds an unique identity of an object.
4)How we can print object ID.
-Object ID printed with help of object class which is a service provider class having 9().
5)what is object class.
-it is a super class of all predefined & userdefined class.
6)Write a prog to get name of main thread in java.
-class A
{
psvm(String args [])
{
s.o.pln(Thread.currentThread().getName());
}
}
7)length vs length()
-length
is
data menmber
of proxy class
whereas
length() is a string class().

Q1. Explain JVM in ur own language.
Ans. 
JVM is an abstract machine that executes Java bytecode.
• JVM stands for Java Virtual Machine.

• It is responsible for interpreting and executing Java bytecode.

• JVM provides platform independence to Java programs.

• It has its own memory management system and garbage collector.

• JVM can be implemented on different operating systems.

• Examples of JVM languages include Java, Kotlin, and Scala.
Answered by AI
Add your answer
Q2. Exlplaing Multhreading.
Add your answer

Q1. Hashmap inter working, arraylist internal working, concurrent hashmap, comprator vs comprable, list, set, queue, transient vs volatile, Serializable, executor framework,
Add your answer
Q2. Java 8 features especaily stream
Add your answer

Q1. What are your salary expectations?
Ans. 
I am open to discussing salary based on the responsibilities and requirements of the position.
• I am flexible and open to negotiation.

• I am looking for a competitive salary based on my skills and experience.

• I would like to be compensated fairly for the value I can bring to the company.

• I am interested in discussing the overall compensation package, including benefits and bonuses.
Answered by AI
Add your answer
Q2. What is your family background?
Ans. 
My family background is diverse and multicultural, with members from different countries and professions.
• My parents are from different countries, which has exposed me to different cultures and languages.

• My father is a doctor and my mother is an engineer, which has influenced my interest in both medicine and technology.

• I have relatives who are teachers, artists, and entrepreneurs, which has broadened my perspective on v...read more
Answered by AI
Add your answer
Q3. Why are you looking for a change?
Ans. 
Looking for new challenges and growth opportunities.
• Seeking a more challenging role to enhance my skills and knowledge.

• Interested in working with new technologies and frameworks.

• Want to be part of a dynamic and innovative team.

• Desire for career growth and advancement.

• Looking for a better work-life balance.
Answered by AI
Add your answer
Q4. Where do you see yourself in 5 years?
Ans. 
In 5 years, I see myself as a highly skilled Fullstack Java Developer, leading a team and working on complex projects.
• Leading a team of developers

• Working on complex projects

• Continuously improving my skills

• Contributing to the success of the company
Answered by AI
Add your answer
Q5. Tell me about yourself.
Ans. 
I am a Fullstack Java Developer with experience in developing web applications using Java, Spring, and JavaScript.
• I have a strong understanding of Java programming language and its frameworks like Spring and Hibernate.

• I am proficient in front-end technologies like HTML, CSS, and JavaScript.

• I have experience in developing RESTful APIs and working with databases like MySQL and MongoDB.

• I am familiar with Agile development...read more
Answered by AI
Add your answer

Q1. SQL - a table with emp-id, emp-name, manager-id, Need to find the manger name for each emplyee.
Add your answer
Q2. FizzBuzz - if number is divisible by 3 print "fizz", if by 5 print "buzz", if by both "fizzbuzz"
Ans. 
A simple program to print 'fizz' for multiples of 3, 'buzz' for multiples of 5, and 'fizzbuzz' for multiples of both.
• Iterate through numbers from 1 to n.

• Use modulo operator to check divisibility by 3 and 5.

• Print 'fizz', 'buzz', or 'fizzbuzz' accordingly.
Answered by AI
View 1 more answer
Q3. Is it necessary for classes implementing an interface to implement interface methods?
Ans. 
Yes, classes implementing an interface must implement interface methods.
• Classes implementing an interface must provide concrete implementations for all methods declared in the interface.

• Failure to implement all interface methods will result in a compilation error.

• Interfaces are used to define a contract that implementing classes must adhere to.
Answered by AI
Add your answer
Q4. Spring basics - annotations
Add your answer

Q1. Spring boot basics
Add your answer

Q1. Talked about my previous companies and salary. Before they conduct the interview I had told them my expectation, while negotiation they denied for providing that and were offering just 10% hike over my cur...read more
Add your answer

Q1. Tell you about me self
Add your answer
Q2. Coding test for me
Add your answer
Q3. Servlet question
Add your answer
Q4. Jdbc question and mysql database
Add your answer
Q5. What is cookie ? why use to create web application
Ans. 
A cookie is a small piece of data stored on the user's computer by the web browser, used to track user activity and personalize user experience.
• Cookies are used to store user preferences, login information, and shopping cart items.

• They help websites remember users and their preferences, making the browsing experience more personalized.

• Cookies can also be used for tracking user behavior, such as analyzing website traffi...read more
Answered by AI
Add your answer

Core java, servlet ,jdbc

Q1. What is sychronization ?
Ans. 
Synchronization is the process of coordinating multiple threads to ensure safe and consistent access to shared resources.
• Synchronization is used to prevent race conditions and ensure thread safety.

• It can be achieved using synchronized blocks or methods.

• Synchronization can cause performance issues if not used properly.

• Example: Synchronizing access to a shared counter variable in a multi-threaded application.
Answered by AI
Add your answer
Q2. What is encapsulation ?
Ans. 
Encapsulation is the process of hiding implementation details and providing access to only necessary information.
• Encapsulation is achieved through access modifiers such as public, private, and protected.

• It helps in achieving data abstraction and information hiding.

• Encapsulation provides better control over the data and prevents unauthorized access.

• Example: A class with private variables and public methods to access the...read more
Answered by AI
Add your answer
Q3. What is interface in java ?
Ans. 
An interface in Java is a collection of abstract methods and constants that can be implemented by a class.
• Interfaces are used to achieve abstraction and provide a way to implement multiple inheritance in Java.

• All methods in an interface are abstract by default and cannot have a body.

• A class can implement multiple interfaces but can only extend one class.

• Interfaces can also have default and static methods with a body.

• Ex...read more
Answered by AI
Add your answer
Q4. What is collection framework?
Ans. 
Collection framework is a set of classes and interfaces that provide a way to store and manipulate groups of objects.
• It provides interfaces like List, Set, Queue, etc. for storing collections of objects.

• It also provides classes like ArrayList, HashSet, PriorityQueue, etc. that implement these interfaces.

• It allows easy manipulation of collections using methods like add, remove, contains, etc.

• It provides algorithms like ...read more
Answered by AI
Add your answer
Q5. What is diffrence between Arraylist and vector ?
Ans. 
ArrayList is not synchronized while Vector is synchronized.
• ArrayList is faster than Vector as it is not synchronized.

• Vector is thread-safe while ArrayList is not.

• Vector is a legacy class while ArrayList is not.

• Vector can grow by a specified amount while ArrayList grows by 50% of its size.

• Example: ArrayList list = new ArrayList<>(); Vector vector = new Vector<>();

• Example: list.add(1); vector.add(1);

• Example: list.get(0);
Answered by AI
Add your answer
Q6. What are the legacy classes in java?
Ans. 
Legacy classes in Java are the classes that have been replaced by newer versions but are still supported for backward compatibility.
• Legacy classes are part of the Java API and are still supported for backward compatibility.

• They have been replaced by newer versions but are still used in older applications.

• Examples of legacy classes include Vector, Hashtable, and Enumeration.

• Legacy classes are not recommended for use in ...read more
Answered by AI
Add your answer
Q7. What is joins in SQL ?
Ans. 
Joins in SQL are used to combine data from two or more tables based on a related column.
• Joins are used to retrieve data from multiple tables in a single query.

• There are different types of joins such as inner join, left join, right join, and full outer join.

• Inner join returns only the matching rows from both tables, left join returns all rows from the left table and matching rows from the right table, right join returns...read more
Answered by AI
Add your answer
Q8. What is autoboxing and auto-unboxing ?
Ans. 
Autoboxing is the automatic conversion of primitive data types to their corresponding object wrapper classes.
• Autoboxing allows primitive data types to be used as objects.

• Auto-unboxing is the reverse process of autoboxing.

• Autoboxing and auto-unboxing are performed automatically by the compiler.

• Example: int i = 10; Integer j = i; // autoboxing

• Example: Integer j = 10; int i = j; // auto-unboxing
Answered by AI
Add your answer
Q9. Difference between where clause and having clause in SQL ?
Ans. 
Where clause filters rows before grouping, having clause filters groups after grouping.
• Where clause is used to filter rows based on a condition before grouping.

• Having clause is used to filter groups based on a condition after grouping.

• Where clause is used with SELECT, UPDATE, DELETE statements.

• Having clause is used with SELECT statement and GROUP BY clause.

• Where clause cannot contain aggregate functions.

• Having clause c...read more
Answered by AI
Add your answer

Q1. Tech panel did not show up
Add your answer

Q1. Tell me about yourself?
Ans. •I'm Akashdeep Prasad. • I'm in my early twenties. • I'm born and brought up in Mumbai, Andheri but currently I'm reside in Thane. - Now, coming to my highest qualification :- • I have completed my graduation in Bachelor of Science in Information Technology from University of Mumbai. - I like to share my certification with you :- • I'm certified Java Full Stack Developer. - Sir, I like to share my hobbies with you :...read more
Answered by smilingnova
Add your answer
Q2. Why should I hire you ?
Add your answer
Q3. What is your salary expectation?
Add your answer

Q1. I forgot question
Add your answer

Q1. I can't remember what questions asked
Add your answer

Q1. Q1 - tell me about yourself After my introduction he directly jump into coding and asked me simple array manipulation question. Q3 - balanced string - you have a String = "()()()" or "(()" or "(()). The ou...read more
Add your answer

Q1. The interviewers don't know how to speak English and are worst in communication. Q1 - Convert int a=123 to string. I told him you can do it with in built method but he asked me to do without it. I told h...read more
Add your answer