Tcs technical interview questions are discussed here in this post. This article covers several C programming questions which were asked during the TCS interview as you all know that every year tcs recruits a lot of engineering freshers. After qualifying for the written test, generally, there are three rounds, TCS technical interview, hr interview, and Managerial round.

So first, let us talk about the technical interview of TCS. During the technical interview of TCS, several questions were asked from the C programming language in the previous recruitment of TCS. Here in this post, I am going to share some questions which were asked in TCS technical interview.

Q1. Is C a middle-level Language Justify it?

Answer: C is a middle-level language because it has the features of both low-level languages. 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 the 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 exist for the lifetime of the program. It means the value of the static variable is retained between the function call.

Q3. What is the Difference between Header File and Library?

Answer: The header file contains only the predefined function declaration. It means only the function prototype is declared in the header file. These functions are defined in the library.

Q4.What are macros? Why we use them.

Answer: In C programming Macros are processor directive which will be replaced at compile time. The benefit of using macros is that they can reduce the time for replacing the same values and the disadvantage of using macros is that they return the code they do not function calls.

Q5.What is the Difference between call by reference and market by value?

Answer: When we talk about the call by value, then it just passes the value from the caller to the 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 change.

Q6. What is a pointer in C?

Answer: Pointer is a variable in a program that points to another variable it means it stores the address of another variable.

Q7. What is the argument? Difference between formal and actual argument.

Answer: Well! The major Difference between actual and formal arguments is that real arguments are the source of information, calling programs to pass actual arguments to called functions. When we call a function in the 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, whereas a void pointer is a generic pointer introduced by ANSI. The generic pointer can hold the address of any data type. It is declared like a normal pointer using a void pointer.

Q10. Consider the two following declarations.

const char *p,

 char const *p

What is the Difference between these two declarations? 

Answer:

1) const char *p

This declaration represents 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 declarations represent a pointer to a const char, and the position of ‘*'(asterisk) is also the same.

Q11. Why do we include the 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 the advantages of using function?

Q19. Write a program to find factorial of a number using recursive function.

Q20. Describe two different ways to concatenate two strings.

Q21. What is #ifdef? What is its application?