TCS interview questions and answers
This article cover several C programming questions which were asked during tcs interview. As you all know that every year tcs recruits a lot of engineering freshers. After qualifying the written test generally there are three rounds, tcs technical interview, hr interview and Managerial round.
So first let us talk about technical interview of tcs. During the technical interview of tcs several questions were asked from C programming language in previous recruitment of tcs. Here in this post I am going to share some questions which were asked in tcs technical interview.
Q1. C is a middle level Language Justify it ?
Answer : C is a middle level language because it has the features of both low level language . low level language features such as interaction with hardware and high level language features such as it has proper syntax and semantics ,structure and rule to write the code in English language.
Q2. .What does static variable mean?
Answer: In general static is an access qualifier. But when we declare a variable as static inside a function , the scope of that variable is limited to the function, but it will exists for the life time of the program. It means value of static variable is retained between the function call.
Q3. What is difference between Header File and Library?
Answer: Header file contains only the predefined function declaration it menas only function prototype is declared in header file. These functions are defined in library.
Q4. .What are macros? Why we use them.
Answer: In C programming Macros are processor directive which will be replaced at compile time. Benefit of using macros is that they can reduce time for replacing the same values and disadvantage of using macros is that they just replace the code they are not function calls.
Q5. .What is Difference between call by reference and call by value?
Answer : When we talk about call by value then it just passes the value from caller to calling function so the called function cannot modify the values in caller function Ok. But when we use call by reference then it will pass the address to the caller function instead of value if called function requires to modify any value it can directly modify.
Q6. What is pointer in C ?
Answer : Pointer is a variable in a program which points to another variable it means it store the address of another variable.
Q7. What is argument? Difference between formal and actual argument.
Answer: Well ! Major difference between actual and formal arguments is that actual arguments are the source of information; calling programs pass actual arguments to called functions. When we call a function in main() function then at that time passed arguments are called actual arguments. When values are passed to a called function the values present in actual arguments are copied to the formal arguments.
Q8. What are the different storage classes in C ?
Answer: There are four types of storage classes in C. They are extern, register, auto and static.
Q9. Tell me the difference between null and void pointer?
Answer: A Null pointer is a pointer that has the value 0 where as a void pointer is a generic pointer introduced by ANSI. Generic pointer can hold the address of any data type. It is declared like a normal pointer using void pointer.
Q10. Consider the two following declaration.
const char *p ,
char const *p
What is the difference between the these two declaration?
1) const char *p
This declaration represent a Pointer to a Constant char (‘p’ isn’t modifiable but the pointer is)
2) char const *p
This declaration Also pointer to a constant Char
There is no difference between const char *p and char const *p as both declaration represent a pointer to a const char and position of ‘*'(asterik) is also same.
Q11. Why we include header file in C? what is in a header file? How compiler handle it?
Q12. What is Dangling Pointer?
Q13. Functions of calloc(), malloc() and free().
Q14. What is an Array. Can we store a string and integer together in an Array? If I can’t, and I want to, what should I do?
Q15. Write a program on Palindrome Number/Palindrome String/Fibonacci with recursive function/Factorial using recursion.
Q16. Difference between structure and union.
Q17. Scope of a variable, local global. Which is given preference.
Q18. What are advantages of using function ?
Q19. Write a program to find factorial of a number using recursive function.
Q20. Describe 2 different ways to concatenate two strings.
Q21. What is #ifdef ? What is its application?
Q22. Difference between keyword and identifier.