Interview Questions.

TCS Technical Interview Questions and Answers


TCS Technical Interview Questions and Answers

Q1. What are the principle ideas of OOPS?






Classes and Object

Q2. What is your strongest programming language (Java, ASP, C, C++, VB, HTML, C#, and many others.)? 

Ans: Point to don't forget: Before interview You must decide your Favorite programming language and be organized based on that question.

Q3. What  is difference among DDL and DML command?

Ans: DDL stands for Data Definition Language. DML stands for Data Manipulation Language. DDL commands are used to create,adjust,truncate,drop,rename etc. Where DML are used to insert,update,delete,merge etc.,

Q4 . What are the differences among C and C++?


C can run maximum of the code of C, but C can not run C code.

C supports procedural programming paradigm whereas C supports each procedural and object oriented programming paradigm

C is a characteristic driven and C is an item driven language.

C doesn't permit feature definitions inside systems whereas in C feature definition can be inside structures.

C does not aid reference variables but C does help.

Q5. What are the  Differences among C and Java?


JAVA is Object-Oriented at the same time as C is procedural.

Java is an Interpreted language while C is a compiled language.

C is a low-level language while JAVA is a excessive-degree language.

C makes use of the pinnacle-down method even as JAVA uses the lowest-up technique.

Pointer cross behind the curtain in JAVA even as C requires explicit coping with of tips.

The Behind-the-scenes Memory Management with JAVA & The User-Based Memory Management in C.

JAVA helps Method Overloading while C does not help overloading at all.

Unlike C, JAVA does not guide Preprocessors, & does not truely them.

The standard Input & Output Functions--C makes use of the printf & scanf features as its fashionable enter & output while JAVA uses the System.Out.Print & System.In.Read features.

Exception Handling in JAVA And the errors & crashes in C.

Q6. In header files whether functions are declared or defined?


Functions are declared within header document. That is function prototypes exist in a header report,no longer function bodies. They are defined in library (lib).

Q7. What are limitations of union?

Ans: This manner if one member variable of union is up to date then the relaxation will be up to date as nicely. This also leads compilation error while initializing multiple individuals at a time because the memory locations aren't exceptional. So in case of union most effective one member should be initialized at a time.

Q8. What are the distinct storage training in C ?

Ans: There are four styles of garage classes in C. They are extern, sign up, automobile and static

Q9. What does static variable mean?

Ans: Static is an get admission to qualifier. If a variable is said as static internal a feature, the scope is confined to the characteristic,however it'll exists for the existence time of the program. Values will be endured between successive

calls to a characteristic

Q10. How do you print an deal with ?

Ans: Use %p in printf to print the address.

Q11. Difference among pass via reference and pass by price?

Ans: Pass with the aid of fee simply passes the cost from caller to calling function so the known as characteristic cannot alter the values in caller feature. But Pass by using reference will skip the address to the caller characteristic as opposed to value if referred to as feature calls for to modify any value it could immediately adjust.

Q12.What is a category?

Ans: Class is a consumer-described data kind in C++. It can be created to clear up a selected sort of hassle. After advent the person want now not recognize the specifics of the operating of a category.

Q13. What is encapsulation?

Ans: Encapsulation is binding of attributes and behaviors. Hiding the real implementation and exposing the capability of any object. Encapsulation is the first step closer to OOPS, is the procedure of overlaying up of facts and functions right into a unmarried unit (called class). Its important purpose is to guard the information from out aspect world.

Q14 .What is an item?

Ans: Object is a software program package of variables and associated methods. Objects have kingdom and conduct

Q15. What is the difference among magnificence and structure?

Ans: Structure: Initially (in C) a structure became used to bundle different form of information types collectively to perform a specific capability. But C++ extended the structure to comprise functions also.

The principal distinction is that every one declarations interior a structure are through default public.

Class: Class is a successor of Structure. By default all of the participants within the class are private.

Q16. What is information shape?

Ans: A facts structure is a manner of organizing statistics that considers now not only the items saved, but additionally their courting to every different. Advance information approximately the connection among information objects lets in designing of efficient algorithms for the manipulation of facts.

Q17. What is pointer?

Ans: Pointer is a variable in a application is some thing with a name, the cost of that can range. The way the compiler and linker handles this is that it assigns a particular block of reminiscence inside the pc to keep the value of that variable.

Q18. What is the distinction between null and void pointer?

Ans: A Null pointer has the price zero. Void pointer is a regular pointer introduced by ANSI. Generic pointer can maintain the deal with of any information type.

Q19. What is function overloading 

Ans: Function overloading is a function of C++ that allows us to create multiple capabilities with the equal call, as long as they have specific parameters.Consider the subsequent feature:

int Add(int nX, int nY)

return nX + nY;


Q20. What is function overloading and operator overloading?

Ans: Function overloading: C++ enables numerous features of the identical name to be defined, so long as those functions have distinctive units of parameters (at the least as a ways as their kinds are concerned). This functionality is called feature overloading. When an overloaded feature is called, the C++ compiler selects the proper function by means of examining the wide variety, types and order of the arguments inside the call. Function overloading is usually used to create numerous features of the identical name that carry out similar duties but on special statistics kinds.

Operator overloading permits present C++ operators to be redefined in order that they work on objects of consumer-defined training. Overloaded operators are syntactic sugar for equal characteristic calls. They shape a pleasing facade that doesn't add some thing fundamental to the language (however they are able to improve understandability and decrease upkeep prices).

Q21. What is pal function?

Ans: A friend characteristic for a category is utilized in item-oriented programming to permit get right of entry to to public, private, or protected statistics within the class from the outside. Normally, a characteristic that is not a member of a class cannot get admission to such facts; neither can an outside magnificence. Occasionally, such access could be superb for the programmer. Under those instances, the characteristic or outside elegance can be declared as a friend of the magnificence the usage of the friend keyword.

Q22. What do you imply by inline characteristic?

Ans: The idea behind inline features is to insert the code of a known as function on the point where the function is called. If completed cautiously, this will enhance the software's performance in trade for improved collect time and probably (but no longer usually) an boom within the size of the generated binary executables.

Q23. Tell me something about abstract classes?

Ans: An summary elegance is a class which does not absolutely constitute an item. Instead, it represents a extensive range of various classes of items. However, this illustration extends best to the capabilities that those training of gadgets have in commonplace. Thus, an abstract magnificence affords handiest a partial description of its objects.

Q24. What is the difference between realloc() and loose()?

Ans: The free subroutine frees a block of memory previously allocated through the malloc subroutine. Undefined results occur if the Pointer parameter isn't a legitimate pointer. If the Pointer parameter is a null fee, no action will occur. The realloc subroutine changes the scale of the block of reminiscence pointed to by way of the Pointer parameter to the range of bytes special by the Size parameter and returns a brand new pointer to the block. The pointer specified via the Pointer parameter should have been created with the malloc, calloc, or realloc subroutines and not been deallocated with the unfastened or realloc subroutines. Undefined effects occur if the Pointer parameter isn't a legitimate pointer.

Q25. What are macros? What are its advantages and disadvantages? 

Ans: Macros are processor directive with a purpose to get replaced at bring together time.

The drawback with macros is that they just update the code they're not feature calls. Further the advantage is they can reduce time for replacing the equal values.

Q26. What is the distinction among an array and a list?

Ans: Array is collection of homogeneous factors. List is collection of heterogeneous elements.

For Array reminiscence allotted is static and continuous. For List reminiscence allocated is dynamic and Random.

Array: User need now not have to maintain in song of next memory allocation.

List: User has to hold in Track of next location in which memory is allocated.

Array uses direct access of stored contributors, listing uses sequential get entry to for individuals.

Q27. What are the differences between systems and arrays?

Ans: Arrays is a set of similar statistics types however Structures can be institution of various data kinds

Q28. Can you listing out the regions wherein information systems are applied significantly?

Ans: Compiler Design,

Operating System,

Database Management System,

Statistical analysis bundle,

Numerical Analysis,


Artificial Intelligence,


Q29. What are the benefits of inheritance?

Ans: It lets in code reusability. Reusability saves time in program development. It encourages the reuse of verified and debugged first-rate software, hence reducing hassle after a gadget becomes useful.

Q30. What are the two integrity rules used in DBMS?

Ans: The two varieties of  integrity regulations are referential integrity regulations and entity integrity rules. Referential integrity regulations dictate that a database does no longer contain orphan overseas key values. This method that

A number one key cost can not be changed if the value is used as a foreign key in a toddler table. Entity integrity dictates that the primary key fee cannot be Null.

Q31.  What is Doubly link listing?

Ans: A doubly connected listing is a connected records structure that consists of a set of sequentially linked information known as nodes. Each node carries  fields, known as hyperlinks, which are references to the preceding and to the following node in the collection of nodes. The starting and finishing nodes' previous and subsequent links, respectively, factor to a few type of terminator, commonly a sentinel node or null, to facilitate traversal of the list. If there may be simplest one sentinel node, then the listing is circularly connected thru the sentinel node. It may be conceptualized as  singly connected lists formed from the equal records objects, but in opposite sequential orders.

Q32. What is command line argument?

Ans: Getting the arguments from command activate in c is known as command line arguments. In c predominant characteristic has 3 arguments.They are:

Argument counter

Argument vector

Environment vector

Q33. What is cache memory ?

Ans: Cache Memory is used by the primary processing unit of a pc to lessen the common time to get right of entry to memory. The cache is a smaller, quicker reminiscence

which stores copies of the data from the most regularly used main memory locations. As lengthy as most reminiscence accesses are cached memory places, the average

latency of memory accesses may be in the direction of the cache latency than to the latency of predominant memory.

Q34.What is debugger?

Ans: A debugger or debugging tool is a computer software that is used to test and debug other applications

Q35. Const char *p , char const *p What is the distinction between the above two?


const char *p - Pointer to a Constant char ('p' isn't always modifiable but the pointer is)

char const *p - Also pointer to a steady Char

However if you had something like:

char * const p - This pronounces 'p' to be a consistent pointer to an char. (Char p is modifiable but the pointer isn't always)

Q36. What is conversion constructor?    

Ans: A conversion constructor is a single-parameter constructor that is declared without the feature specifier 'explicit'. The compiler makes use of conversion constructors to transform gadgets from the sort of the primary parameter to the kind of the conversion constructor's elegance.To define implicit conversions, C++ makes use of conversion constructors, constructors that be given a single parameter and initialize an item to be a replica of that parameter.

Q37. What is a spanning Tree?

Ans: A spanning tree is a tree related to a network. All the nodes of the graph seem on the tree as soon as. A minimum spanning tree is a spanning tree prepared in order that the overall facet weight between nodes is minimized.

Q38. Why have to we use data ware housing and how can you extract information for evaluation with instance?

Ans: If you need to get facts on all of the strategies of designing, keeping, constructing and retrieving records, Data warehousing is the correct approach. A facts warehouse is premeditated and generated for supporting the decision making manner within an company.

Data mining is a powerful new technology to extract information for analysis.

Q39.Differentiate among Complier and Interpreter?

Ans: An interpreter reads one coaching at a time and consists of out the moves implied by way of that coaching. It does no longer perform any translation. But a compiler translates the complete instructions

Q40. What is scope of a variable?

Ans: Scope refers back to the visibility of variables. It is very beneficial if you want to restrict a variable's scope to a unmarried function. In other phrases, the variable wil have a restricted scope

Q41. What is an interrupt?

Ans: Interrupt is an asynchronous sign informing a program that an occasion has occurred. When a application gets an interrupt sign, it takes a unique action.

Q42. What is user described exception in Java?

Ans: The key phrases utilized in java utility are try, catch and subsequently are used in enforcing used-described exceptions. This Exception elegance inherits all of the technique from Throwable elegance.

Q43. What is java Applet?

Ans: Applet is java application that may be embedded into HTML pages. Java applets runs on the java enables net browsers including mozila and internet explorer. Applet is designed to run remotely on the consumer browser, so there are a few restrictions on it. Applet can't get admission to system resources on the neighborhood computer. Applets are used to make the web site greater dynamic and wonderful.

Q44. What do you know approximately the rubbish collector?

Ans: Garbage collection is the systematic recovery of pooled pc storage that is being used by a program whilst that program not wishes the storage. This frees the garage for use by using different packages (or methods inside a application). It additionally ensures that a software the use of increasing quantities of pooled storage does no longer attain its quota (in which case it is able to now not be able to characteristic).

Garbage collection is an automated reminiscence management function in lots of modern programming languages, which include Java and languages in the .NET framework. Languages that use rubbish series are regularly interpreted or run inside a virtual machine like the JVM. In every case, the surroundings that runs the code is likewise liable for rubbish series.

Q45. Write a Binary Search software

Ans: int binarySearch(int arr[],int length, int item)

int left, right, middle;

left = 0;

proper = length-1;

while(left <= right)

middle = ((left + right)/2);

if(item == arr[middle])



if(item > arr[middle])

left = middle+1;


proper = center-1;

go back(-1);