HCLTech Fullstack Java Developer Interview Questions and Answers

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. Java common question on hashmap, stream api
Add your answer

Q1. Agile methodology
Add your answer
Q2. Decorators in annular
Ans. 
Decorators in Angular are functions that allow you to modify or extend the behavior of classes or methods.
• Decorators are used to add metadata to classes or methods in Angular applications.

• They are prefixed with @ symbol and are followed by the decorator name.

• Common decorators in Angular include @Component, @Directive, @Injectable, @Input, @Output, etc.

• Decorators can be used for various purposes such as defining compone...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