Banking Domain interview Questions on Java Part-1

I am including some of the interview questions which are asked in citibank from different different individuals . Right now I am not including answers of these questions but very soon will add the same as well!!

Interview - A

1. Ask details about last assignment, what are the component, roles and responsibility; 2.use of multithreading and singleton design pattern in last assignment.

3. Singleton Design pattern, double check 4.what are the collection used, which one is favourite data structure 5.you have less memory resource, you have an array , once your array gets full how will you insert new element in array without removing existing element.

6.you have an employee class which contains a arraylist of address , how will you make this class immutable, how will you ensure that client could not remove address from arraylist.

7.what are spring scopes.

8.Two bean id are declared for a single class in spring xml, how many instance will be created.

9. Any question for me.

Interview - B

1. Spring - which one is better – setter or constructor injection

2. In a sorted data how will you find a number with maximum occurrence.

3. About previous project and multithreading and batch processing experience.

4. There is a function that accepts two parameters and returns their sum. How will you synchronize access to it.

5. There are hundred threads, a module is there which can at most allow 5 threads. how to implement the same.

6. Experience in design patterns? What is template design pattern and its usage.

Interview - C

1. From sorted and duplicate elements find frequency of a given element.

2. Find loop in linked list

3. HashMap questions

4. Find nth element from bottom of a linked list

5. How to make class Immutable

Interview - D

1.Brief about yourself and project.

2.Basic pillars of OOPS.

3.Difference between abstract and Interface.

4.How to show end User a message without changing the method signature of already existing class only change the method body (no overriding). For e.g : your withdrawal limit has Exceeded more than 40,000.

5.hashmap and its internal working and some scenario based questions.for e.g hashmap<Object,Object> hm = new Hashmap<>(); hm.put(CAR,TRUCK);// what is the Output : hm.get(new CAR(1,”hatchback”));[CAR and TRUCK are different classes with key value already put in the hashmap]

6.Create your Custom HashMap and what are the functionalities you will put and specifically about Entry class.

7.how to implement custom Singly linkedList.

8.how a hashmap converts map into a keySet or entrySet for e.g set<Entry.map<K,V>> = hm.entrySet<K,v>; (internal working).

9.how to find nth element in a singly linked list.

10.How to ensure the Order of Threads without using wait and notify.

Interview - E

1. Brief Introduction about yourself and Describe the project and technologies you have worked on.

2. Difference between Thread and Process?

3. What are the parameters to keep in mind to convert a application into multithreaded application?

4. A batch takes 3hr to complete without multithreading, what will be the impact if 50 threads are run to complete the batch?

5. Given a class

class counter{

int count;

public void increment()

{

count++

}

}

a. If 2 threads are run what will be the value of variable count.

b. Is there any issue in above code.

c. What will happen if count is declared as volatile

d. How to resolve the issues of above code.

5. When can we use only Volatile?

6. What is deadlock. Write code to generate a deadlock?

7. Write a code to create deadlock using singelton class?

8. Min requirement to generate a deadlock(Min objects / Min threads that are required)?

9. How to create a synchronized map?

10. Difference between ConcurrentHashMap and SynchronizedMap?

11. We have 25 reader threads. Which map would you prefer to use in this scenario.(Hashmap or ConcurrentHashMap or SynchronizedMap)?

12. Write a program to print 1,2,3,4,5...and so on using Threads. Given when thread T1 prints only even number and thread T2 prints only odd number.(Order needs to be sequential).

13. Difference between LinkedList and ArrayList?

14. When will you prefer to use linkedlist and when will you prefer ArrayList?

15. Write a code to generate a node of single linked list?

16. Describe the benefits of TreeSet?

17. What the requirements to implement TreeSet for storing custom Objects?

18. Given a TreeSet<Objects> : Now 2 objects 1 of Employee Class and Other of Department class are inserted in set. What will be the size of the set?

19. What do you mean by StackOverFlowException?

20. Write a code to generate StackOverFlowException?