Interview Questions and Answers for 'Tata Consultancy (TCS)' | Search Java Interview Question - javasearch.buggybread.com
Javasearch.buggybread.com
Share

Search Interview Questions


 3348 questions in repository.
 There are more than 200 unanswered questions.
Click here and help us by providing the answer.
 Have a video suggestion.
Click Correct / Improve and please let us know.
Label / Company      Label / Company / Text

   



Interview Questions and Answers for 'Tata Consultancy (TCS)' - 86 question(s) found - Order By Newest

next 40
Frequently asked to fresh graduates and less experienced developers. Among the first few questions in many interviews.
  Q1. What are the difference between composition and inheritance in Java?Core Java
Admin
info@buggybread.com
Ans. Composition - has-a relationship between objects.
Inheritance - is-a relationship between classes.

Composition - Composing object holds a reference to composed objects and hence relationship is loosely bound.
Inheritance - Derived object carries the base class definition in itself and hence its tightly bound.

Composition - Used in Dependency Injection
Inheritance - Used in Runtime Polymorphism

Composition - Single class objects can be composed within multiple classes.
Inheritance - Single class can only inherit 1 Class.

Composition - Its the relationship between objects.
Inheritance - Its the relationship between classes.

  Sample Code for inheritance

  Sample Code for composition

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


   Like         Discuss         Correct / Improve     java   java concepts   inheritance  object oriented programming (oops)  oops concepts   composition  object oriented programming (oops)  oops concepts   inheritance  object oriented programming (oops)  oops concepts vs composition  object oriented programming (oops)  oops concepts     Asked in 28 Companies      basic        frequent

Try 5 Question(s) Test


  Q2. Which are the different segments of memory ?Core Java
Anonymous
Ans. 1. Stack Segment - Contains primitives, Class / Interface names and references.

2. Heap Segment - Contains all created objects in runtime, objects only plus their object attributes (instance variables), Static variables are also stored in heap.

3. Code Segment - The segment where the actual compiled Java bytecodes resides when loaded

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

   Like         Discuss         Correct / Improve     java   memory   memory management   stack memory   heap memory   code segment memory   advanced     Asked in 9 Companies      expert        frequent

Try 6 Question(s) Test


Very frequently asked to Fresh graduates.
  Q3. What is the difference between Encapsulation and Abstraction?Core Java
Anonymous
Ans. 1.Abstraction solves the problem at design level while encapsulation solves the problem at implementation level

2.Abstraction is used for hiding the unwanted data and giving relevant data. while Encapsulation means hiding the code and data into a single unit to protect the data from outside world.

3. Abstraction lets you focus on what the object does instead of how it does it while Encapsulation means hiding the internal details or mechanics of how an object does something.

4.For example: Outer Look of a Television, like it has a display screen and channel buttons to change channel it explains Abstraction but Inner Implementation detail of a Television how CRT and Display Screen are connect with each other using different circuits , it explains Encapsulation.

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

   Like         Discuss         Correct / Improve     java   oops   oops concepts   encapsulation  object oriented programming (oops)  oops concepts   abstraction   basic interview question     Asked in 10 Companies      basic        frequent

Try 2 Question(s) Test


Very frequently asked. Favorite question in Walk in Drive of many Indian service companies. Frequently asked in HCL Technologies, TCS and Accenture.
  Q4. What is the difference between final, finally and finalize() ?Core Java
Admin
info@buggybread.com
Ans. final - constant variable, objects cannot be de-referenced, restricting method overriding, restricting class sub classing.

finally - handles exception. The finally block is optional and provides a mechanism to clean up regardless of what happens within the try block. Use the finally block to close files or to release other system resources like database connections, statements etc.

finalize() - method helps in garbage collection. A method that is invoked before an object is discarded by the garbage collector, allowing it to clean up its state.

  Sample Code for final

  Sample Code for finally

  Sample Code for finalize

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


   Like         Discuss         Correct / Improve     java   oops   final   finally   finalize     Asked in 60 Companies      basic        frequent

Try 4 Question(s) Test


Frequently asked question in companies using Hibernate.
  Q5. What is Lazy Initialization in Hibernate ?Hibernate
Admin
info@buggybread.com
Ans. It's a feature to lazily initialize dependencies , relationship and associations from the Database. Any related references marked as @OneToMany or @ManyToMany are loaded lazily i.e when they are accessed and not when the parent is loaded.

  Sample Code for Lazy Initialization

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


   Like         Discuss         Correct / Improve     hibernate   lazy loading hibernate   lazy initialization hibernate   architecture     Asked in 77 Companies      Basic        frequent

Try 2 Question(s) Test


  Q6. Explain OOPs

or

Explain OOPs Principles

or

Explain OOPs Concepts

or

Explain OOPs features

or

Tell me something about OOPs
Core Java2017-06-13 08:25:45

Ans. OOPs or Object Oriented Programming is a Programming model which is organized around Objects instead of processes. Instead of a process calling series of processes, this model stresses on communication between objects. Objects that all self sustained, provide security by encapsulating it's members and providing abstracted interfaces over the functions it performs. OOP's facilitate the following features

1. Inheritance for Code Reuse
2. Abstraction for modularity, maintenance and agility
3. Encapsulation for security and protection
4. Polymorphism for flexibility and interfacing

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


   Like         Discuss         Correct / Improve     oops  oops features     Asked in 236 Companies      basic        frequent


Recently asked in TCS , Tech Mahindra, HCL , Accenture and Fidelity.
  Q7. Explain Flow of Spring MVC ?Spring
Admin
info@buggybread.com
Ans. The DispatcherServlet configured in web.xml file receives the request.

The DispatcherServlet finds the appropriate Controller with the help of HandlerMapping and then invokes associated Controller.

Then the Controller executes the logic business logic and then returns ModeAndView object to the DispatcherServlet.

The DispatcherServlet determines the view from the ModelAndView object.

Then the DispatcherServlet passes the model object to the View.

The View is rendered and the Dispatcher Servlet sends the output to the Servlet container.

Finally Servlet Container sends the result back to the user.

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

   Like         Discuss         Correct / Improve     j2ee   spring   mvc   frameworks   web applications   architecture     Asked in 10 Companies      Basic        frequent


Basic and Very Frequently asked.
  Q8. What is Polymorphism in Java ?Core Java2016-11-06 09:10:54

Ans. Polymorphism means the condition of occurring in several different forms.

Polymorphism in Java is achieved in two manners

1. Static polymorphism is the polymorphic resolution identified at compile time and is achieved through function overloading whereas

2. Dynamic polymorphism is the polymorphic resolution identified at runtime and is achieved through method overriding.

  Sample Code for overloading

  Sample Code for overriding

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

   Like         Discuss         Correct / Improve     polymorphism  object oriented programming (oops)  oops concepts  oops concepts     Asked in 107 Companies      Basic        frequent

Try 2 Question(s) Test


  Q9. What is a String Pool ?Core Java
Anonymous
Ans. String pool (String intern pool) is a special storage area in Java heap. When a string is created and if the string already exists in the pool, the reference of the existing string will be returned, instead of creating a new object and returning its reference.

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

   Like         Discuss         Correct / Improve     java   oops   string   string class   string pool   heap memory     Asked in 31 Companies      intermediate        frequent

Try 2 Question(s) Test


Frequently asked question in companies using hibernate.
  Q10. Difference between first level and second level cache in hibernate ?Hibernate
Admin
info@buggybread.com
Ans. 1. First level cache is enabled by default whereas Second level cache needs to be enabled explicitly.

2. First level Cache came with Hibernate 1.0 whereas Second level cache came with Hibernate 3.0.

3. First level Cache is Session specific whereas Second level cache is shared by sessions that is why First level cache is considered local and second level cache is considered global.

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


   Like         Discuss         Correct / Improve     hibernate   orm   hibernate cache   architecture   technical lead     Asked in 18 Companies      Intermediate        frequent


Very frequently asked. Favorite question in Walk in Drive of many Indian service companies.
  Q11. Difference between TreeMap and HashMap ?Core Java
Anonymous
Ans. They are different the way their elements are stored in memory. TreeMap stores the Keys in order whereas HashMap stores the key value pairs randomly.

  Sample Code for treemap

  Sample Code for hashmap

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

   Like         Discuss         Correct / Improve     java   collections   map   treemap   hashmap     Asked in 31 Companies      basic        frequent

Try 1 Question(s) Test


Very frequently asked across all types of companies.
  Q12. Difference between HashMap and Hashtable?Core Java
Anonymous
Ans. Hashtable is synchronized whereas HashMap is not.HashMap allows null values whereas Hashtable doesnt allow null values.

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


   Like         Discuss         Correct / Improve     java   collections   hashmap   map   hashtable   basic interview question   ebay   tcs    hcl technologies   infosys technologies     Asked in 14 Companies      basic        frequent

Try 2 Question(s) Test


Very Frequently asked. Have been asked in HCL Technologies very frequently ( based on 3 feedback ). Among first few questions in many interviews.
  Q13. Differences between abstract class and interface ?Core Java
Admin
info@buggybread.com
Ans. Abstract classes can have both abstract methods ( method declarations ) as well as concrete methods ( inherited to the derived classes ) whereas Interfaces can only have abstract methods ( method declarations ).

A class can extend single abstract class whereas it can implement multiple interfaces.

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


   Like         Discuss         Correct / Improve     java   classes   abstract class   interfaces     Asked in 65 Companies      basic        frequent


Very Frequently asked across all type of companies and across all levels.
  Q14. Difference between Public, Private, Default and Protected ?Core Java
Anonymous
Ans. Private - Not accessible outside object scope.

Public - Accessible from anywhere.

Default - Accessible from anywhere within same package.

Protected - Accessible from object and the sub class objects.

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

   Like         Discuss         Correct / Improve     java   oop   access specifier   public   private   default   protected   basic interview question     Asked in 11 Companies      basic        frequent

Try 1 Question(s) Test


Very frequently asked. Favorite question in Walk in Drive of many Indian service companies.
  Q15. What is a final method ?Core Java
Anonymous
Ans. Its a method which cannot be overridden. Compiler throws an error if we try to override a method which has been declared final in the parent class.

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

   Like         Discuss         Correct / Improve     java   oops   final   final method     Asked in 30 Companies      basic        frequent

Try 1 Question(s) Test


  Q16. What is casting?Core Java
Anonymous
Ans. There are two types of casting, casting between primitive numeric types and casting between object references. Casting between numeric types is used to convert larger values, such as double values, to smaller values, such as byte values. Casting between object references is used to refer to an object by a compatible class, interface, or array type reference

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

   Like         Discuss         Correct / Improve     java   data types   casting  type casting   basic interview question     Asked in 8 Companies      basic        frequent


Very Frequently asked to fresh graduates and less experienced. Favorite question in Walk in drives. Frequently asked in Indian Services companies.
  Q17. Difference between Overloading and Overriding ?Core Java
Anonymous
Ans. Overloading - Similar Signature but different definition , like function overloading.

Overriding - Overriding the Definition of base class in the derived class.

  Sample Code for overloading

  Sample Code for overriding

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

   Like         Discuss         Correct / Improve     java   oops   overloading   overriding   oops concepts   basic interview question     Asked in 82 Companies      basic        frequent

Try 1 Question(s) Test


  Q18. Difference between SAX and DOM Parser ?Xml
Admin
info@buggybread.com
Ans. A DOM (Document Object Model) parser creates a tree structure in memory from an input document whereas A SAX (Simple API for XML) parser does not create any internal structure.

A SAX parser serves the client application always only with pieces of the document at any given time whereas A DOM parser always serves the client application with the entire document no matter how much is actually needed by the client.

A SAX parser, however, is much more space efficient in case of a big input document whereas DOM parser is rich in functionality.

Use a DOM Parser if you need to refer to different document areas before giving back the information. Use SAX is you just need unrelated nuclear information from different areas.

Xerces, Crimson are SAX Parsers whereas XercesDOM, SunDOM, OracleDOM are DOM parsers.

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

   Like         Discuss         Correct / Improve     java   xml   parsers   sax   dom parser   difference   architecture   technical lead   technical architect  markup language      Asked in 14 Companies        frequent

Try 1 Question(s) Test


Frequently asked to fresh graduates and less experienced.
  Q19. Difference between Composition and Inheritance ?Core Java
Admin
info@buggybread.com
Ans. Inheritance means a object inheriting reusable properties of the base class. Compositions means that an abject holds other objects.

In Inheritance there is only one object in memory ( derived object ) whereas in Composition , parent object holds references of all composed objects.

From Design perspective - Inheritance is "is a" relationship among objects whereas Composition is "has a" relationship among objects.

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


   Like         Discuss         Correct / Improve     java   oops   oops concepts   inheritance  object oriented programming (oops)  oops concepts   composition  object oriented programming (oops)  oops concepts   difference between   basic interview question     Asked in 12 Companies      basic        frequent

Try 2 Question(s) Test


Almost sure to be asked in every company using any Dependency Injection framework ( Spring, Guice etc )
  Q20. What is Dependency Injection or IOC ( Inversion of Control ) ?Design

Ans. It is a Design Pattern that facilitates loose coupling by sending the dependency information ( object references of dependent object ) while building the state of the object. Objects are designed in a manner where they receive instances of the objects from other pieces of code, instead of constructing them internally and hence provide better flexibility.

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

   Like         Discuss         Correct / Improve     design patterns   ioc ( Inversion of Control )  dependency injection     Asked in 80 Companies      intermediate        frequent


  Q21. What are the different types of inner classes ?Core Java
Anonymous
Ans. Simple Inner Class,
Local Inner Class,
Anonymous Inner Class,
Static Nested Inner Class.

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

   Like         Discuss         Correct / Improve     java   inner classes   classes     Asked in 6 Companies      basic        frequent

Try 1 Question(s) Test


Very frequently asked. Favorite question in Walk in Drive of many Indian service companies.
  Q22. What is a Final Variable ?Core Java
Anonymous
Ans. Final variable is a variable constant that cannot be changed after initialization.

  Sample Code for final variable

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

   Like         Discuss         Correct / Improve     oops   java   final   final variable   basic interview question     Asked in 12 Companies      basic        frequent

Try 1 Question(s) Test


Very frequently asked in phone and walk in interviews.
  Q23. What are Marker Interfaces ? Name few Java marker interfaces ?Core Java
Anonymous
Ans. These are the interfaces which have no declared methods.Serializable and cloneable are marker interfaces.

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

   Like         Discuss         Correct / Improve     java   oops   interfaces   marker interface   serializable   clonable     Asked in 21 Companies      intermediate        frequent

Try 1 Question(s) Test


Frequently asked to fresh graduates.
  Q24. What is a Deadlock ?Operating System
Anonymous
Ans. When two threads are waiting each other and cant precede the program is said to be deadlock.

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

   Like         Discuss         Correct / Improve     java   threads   multi threading   operating system   deadlock  concurrency     Asked in 23 Companies      basic        frequent


Very frequently asked.Usually among first few questions.
  Q25. What is MVC ? Design
Anonymous
Ans. MVC is a Design Pattern that facilititates loose coupling by segregating responsibilities in a Web application

1. Controller receives the requests and handles overall control of the request
2. Model holds majority of the Business logic, and
3. View comprise of the view objects and GUI component

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

   Like         Discuss         Correct / Improve     j2ee   mvc   mvc design pattern   design pattern   struts   spring   web application   web frameworks   ebay     Asked in 60 Companies      basic        frequent

Try 1 Question(s) Test


 Q26. What is Generalization and Specialization in terms of casting ?Core Java
Admin
info@buggybread.com
Ans. Generalization or UpCasting is a phenomenon where a sub class is prompted to a super class, and hence becomes more general. Generalization needs widening or up-casting. Specialization or DownCasting is a phenomenon where a super class is narrowed down to a sub class. Specialization needs narrowing or down-casting.

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

   Like         Discuss         Correct / Improve     java   data types   casting  type casting   up casting  type casting   downcasting  type casting   generalization   specialization     Asked in 2 Companies


Very frequently asked in companies using SOA.
  Q27. What are RESTful Web Services ?Rest
Admin
info@buggybread.com
Ans. REST or Representational State Transfer is a flexible architecture style for creating web services that recommends the following guidelines -

1. http for client server communication,
2. XML / JSON as formatiing language ,
3. Simple URI as address for the services and,
4. stateless communication.

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

   Like         Discuss         Correct / Improve     java   web services   rest   java   j2ee  architecture     Asked in 14 Companies      intermediate        frequent


 Q28. What are the contents of Hibernate configuration file ( hibernate.cfg.xml ) ?Hibernate
Admin
info@buggybread.com
Ans. HBM Files ( Mapping )
DB Connection ( DB Connection String , User Name , Password , Pool Size )
SQL Dialect ( SQL variant to be generated )
Show SQL ( Show / No show SQL on Console )
Auto Commit ( True / False )

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

   Like         Discuss         Correct / Improve     hibernate   configuration   barclays     Asked in 11 Companies


Frequently asked to fresh graduates.
 Q29. What is ACID ?Database2016-11-04 08:09:44

Ans. ACID stands for Atomicity, Consistency, Isolation, Durability is a set of properties of database transactions.

Atomicity means all or nothing. i.e parts of a transaction shouldn't commit if any one of them fails. Either the whole transaction should succeed or it should be complete rollback.

Consistency means that any transaction should lead database from one stabe state to another.

Isolation means that the execution of transaction results in a system state that would be obtained if transactions were executed serially.

Durability means that when a transaction is committed it forms the permanent state of database.

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

   Like         Discuss         Correct / Improve     database  acid     Asked in 7 Companies      Intermediate

Try 1 Question(s) Test


 Q30. If an Abstract class has only abstract methods, What's the difference between such a class and an interface ?Core Java2017-05-07 07:26:29

Ans. Such a class still can have member elements which can be inherited and hence facilitate code reuse. Moreover Abstract class can have non final static elements whereas interfaces are only allowed to have static final elements.

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

   Like         Discuss         Correct / Improve     abstract class   interfaces     Asked in 2 Companies      Basic


  Q31. What is the use of Transient Keyword ?Core Java
Anonymous
Ans. It in Java is used to indicate that a field should not be serialized.

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

   Like         Discuss         Correct / Improve     java   oops   serialization   transient   java keywords     Asked in 38 Companies      intermediate        frequent

Try 2 Question(s) Test


Very Frequently asked.Favorite question in Walk in drive for many Indian service companies.
 Q32. What is a Final Class ?
Anonymous
Ans. A Class that cannot be sub classed.

  Sample Code for final class

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

   Like         Discuss         Correct / Improve     java   oops   final   final class   java keyword   basic interview question     Asked in 3 Companies      basic        frequent


Very Frequently asked. Usually asked along with String Class related questions.
  Q33. What is an immutable class ?Core Java
Anonymous
Ans. Class using which only immutable (objects that cannot be changed after initialization) objects can be created.

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

   Like         Discuss         Correct / Improve     java   oops   immutable  immutability   immutable  immutability class   string class   basic interview question     Asked in 17 Companies      Basic        frequent

Try 2 Question(s) Test


 Q34. What is a Static import ?Core Java
Anonymous
Ans. By static import , we can access the static members of a class directly without prefixing it with the class name.

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

   Like         Discuss         Correct / Improve     java   java5   static import   static   java keyword   static import     Asked in 4 Companies      basic        frequent


Very frequently asked. Usually difference between String,StringBuffer and StringBuilder is asked in different variations.
  Q35. Difference between StringBuffer and StringBuilder ?Core Java
Anonymous
Ans. StringBuffer is synchronized whereas StringBuilder is not.

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

   Like         Discuss         Correct / Improve     java   string   stringbuffer   string class   stringbuilder   synchronized   basic interview question   infosys technologies     Asked in 17 Companies      basic        frequent

Try 1 Question(s) Test


  Q36. What is reflection ?
Anonymous
Ans. It is the process of examining / modifying the behaviour of an object at runtime.

  Sample Code for reflection

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

   Like         Discuss         Correct / Improve     java   reflection   reflection api   ebay   mindtree     Asked in 29 Companies      basic        frequent


Very frequently asked if being interviewed for hibernate. Frequently asked in Tata Consultancy (TCS) and Overstock.com
  Q37. Difference between load and get ?Hibernate
Admin
info@buggybread.com
Ans. If id doesnt exist in the DB load throws an exception whereas get returns null in that case.get makes the call to DB immediately whereas load makes the call to proxy.

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

   Like         Discuss         Correct / Improve     hibernate     Asked in 16 Companies      basic        frequent


 Q38. What are some different logging levels for log4j ?Log4j
Admin
info@buggybread.com
Ans. DEBUG
ERROR
ALL
WARN
INFO
FATAL
OFF
TRACE
TRACE_INT
WARN

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

   Like         Discuss         Correct / Improve     java   log4j   log4j level   logging   error logging     Asked in 10 Companies


 Q39. What are the problems one could face while working with serverless technologies like AWS Lambda ?Amazon Web Services (AWS)2018-01-30 18:05:47

Ans. Warm up time for certain technologies like Java ( JVM Warmup )

Performance

Size of Deployable ( Bigger size packaging should go in S3 )

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

   Like         Discuss         Correct / Improve     serverless technologies  aws lambda  aws serverless computing  amazon cloud serverless computing  amazon lambda     Asked in 1 Companies


  Q40. What is a cookie ?Java EE
admin
info@buggybread.com
Ans. A cookie is a small piece of text stored on a user's computer by the browser for a specific domain. Commonly used for authentication, storing site preferences, and server session identification.

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

   Like         Discuss         Correct / Improve     cookie   javascript   web application   session management   browser   j2ee     Asked in 16 Companies      basic        frequent


next 40


Subscribe to Java News and Posts. Get latest updates and posts on Java from Buggybread.com
Enter your email address:
Delivered by FeedBurner



comments powered by Disqus
 

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

Any input from you will be highly appreciated and It will unlock the application for 10 more requests.

Company Name:
Questions Asked:
         

X Close this