Zensar Placement Paper -: Data Structures Questions And Answers

Zensar Previous Years Solved Sample Placement Papers

1. Technology that needs to improve in day to day life.

   Smart home technology needs to improve in day to day life:

   Improved integration between smart devices for seamless automation.

   Enhanced security features to protect privacy and data.

   More energy-efficient solutions to reduce environmental impact.

2. What is normalization?

   Normalization is the process of organizing data in a database to reduce redundancy and dependency.

   Normalization helps in improving data consistency and accuracy.

   It involves breaking down a large table into smaller tables and defining relationships between them.

   Normalization is achieved through a series of normal forms, such as First Normal Form (1NF), Second Normal Form (2NF), and so on.

   Each normal form has a set of rules that must be followed to ensure data integrity.

   For example, in 1NF, each table cell should contain a single value, and in 2NF, each non-key attribute should be dependent on the entire primary key.

   Normalization is important for efficient database design and maintenance.

3. What is Redux and Redux Saga?

   Redux is a state management library for JavaScript apps. Redux Saga is a middleware for Redux that handles side effects.

   Redux is used to manage the state of an application in a predictable way.

   Redux Saga is a middleware that allows for handling side effects such as asynchronous API calls.

   Redux Saga uses generator functions to make asynchronous code easier to read and test.

   Redux Saga can be used to handle complex workflows such as authentication and data fetching.

4. Do you have any questions for us?

   Yes, I have a few questions regarding the role and responsibilities of a Program Analyst:

   Can you provide more information about the specific projects I will be working on?

   What is the team structure like and who will I be reporting to?

   What are the key performance indicators for this role?

   How does the company measure success for this position?

   What opportunities are there for growth and development within the company?

5. Which languages necessarily need heap allocation in the runtime environment?

   A. Those that support recursion

   B. Those that use dynamic scoping

   C. Those that allow dynamic data structures Answer: Option C

   D. Those that use global variables

6. main() { int i = -1; -i; printf("%d", i); return 0; }

   Ans: -1

7. main() { char *p; printf("%d %d", sizeof(*p), sizeof(p)); }

   Answer: 1, 4

8. How many times will printf be executed?

   
   main() {
     for (int i = -1; i <= 10; i++) {
       if (i == 5) continue;
       else break;
       printf("samsung");
     }
   }
       

   Ans: 0 times

9. Q13) What is a correlated subquery?
   A correlated subquery is a subquery that references a column from a table in the outer query.
   
   • Executed for each row processed by the outer query.
   • Used to filter results based on values from the outer query.
   • Example: SELECT * FROM table1 WHERE column1 = (SELECT MAX(column2) FROM table2 WHERE table1.id = table2.id).

   A. Simple subquery

   B. Correlated subquery Answer: Option B

   C. Aggregation query

   D. None of the above

10. Q14) How is useref used?
    useref is used to access the DOM nodes or state values of child components in a parent component.
    
    • Returns a mutable ref object.
    • Accesses the DOM nodes of child components.
    • Accesses state values of child components in a parent component.
    • Example: const childRef = useRef(); childRef.current.doSomething();

    A. For state management

    B. For accessing DOM nodes Answer: Option B

    C. For data fetching

    D. None of the above

11. Q15) Why do we use public, private, and protected?
    Public, private, and protected are access modifiers used to control the visibility of class members in object-oriented programming.
    
    • Public: Allows access to the member from outside the class.
    • Private: Restricts access to the member only within the class.
    • Protected: Allows access to the member within the class and its subclasses.

    A. Control access

    B. Restrict access

    C. Both A and B Answer: Option C

    D. None of the above

12. Q16) What are the types of normalization?
    Normalization is a process of organizing data in a database to reduce redundancy and dependency.
    
    • First Normal Form (1NF)
    • Second Normal Form (2NF)
    • Third Normal Form (3NF)
    • Boyce-Codd Normal Form (BCNF)
    • Fourth Normal Form (4NF)
    • Fifth Normal Form (5NF) or Project-Join Normal Form (PJNF)

    A. 1NF, 2NF

    B. 3NF, BCNF

    C. 4NF, 5NF

    D. All of the above Answer: Option D

13. Q17) Difference between various SQL joins?
    SQL joins are used to combine rows from two or more tables based on a related column between them.
    
    • INNER JOIN: Returns rows when there is at least one match in both tables.
    • LEFT JOIN: Returns all rows from the left table and matching rows from the right table.
    • RIGHT JOIN: Returns all rows from the right table and matching rows from the left table.
    • FULL JOIN: Returns rows when there is a match in one of the tables.
    • CROSS JOIN: Returns the Cartesian product of the two tables.

    A. INNER JOIN

    B. FULL JOIN

    C. CROSS JOIN

    D. All of the above Answer: Option D