The C programming language, known for its efficiency and control over system resources, remains a fundamental part of computer science education and software development. As a result, many technology companies, including Tata Consultancy Services (TCS), often assess candidates’ proficiency in C during technical interviews. TCS C language questions typically cover a wide range of topics, from basic syntax and data types to more complex concepts like pointers, memory management, and data structures. Preparing for these questions is crucial for candidates aiming to demonstrate their problem-solving skills and understanding of core programming concepts.
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TCS is a leader in the IT services and consulting industry, delivering cutting-edge solutions and services to a wide range of industries around the world. With a strong focus on innovation, employee training and development, and corporate responsibility, TCS is well-positioned for continued success in the future.
The TCS Recruitment process contains four interview rounds we will have a brief discussion of all of them in this section of the blog.
We will discuss each of the four rounds here.
In this section, we will see some of the TCS C Language Questions which are not related to coding but related to the fundamentals of c language.
1. Name all the types of recursion present in C language.
There are mainly six types of recursions:
Yes, these are also some of the different types of recursion.
2. Explain the difference between Interpreter and Compiler.
A compiler and an interpreter are two different approaches to executing code written in the C programming language.
3. What do you understand by the scope of a variable?
The scope of a variable refers to the region of a program where the variable is defined and can be accessed or used. In other words, it defines the visibility and accessibility of a variable within a program.
There are two main types of scope: global scope and local scope. A variable declared outside of all functions has a global scope and is accessible from anywhere in the program. On the other hand, a variable declared inside a function has a local scope and is only accessible within that function.
It’s important to understand the scope of a variable because it affects how a variable can be used and manipulated within a program. For example, if a variable with the same name is declared in both a global scope and a local scope, the local scope will take precedence and shadow the global scope. The value of the global scope variable will not be accessible or affected within the local scope.
4. What do you understand by enumeration?
Enumeration is a programming concept that refers to a named collection of related values that represent distinct elements of a data type. In other words, an enumeration is a set of named constants that represent unique values.
Enumerations are typically defined using a specific syntax in programming languages, such as the enum keyword in C, C++, and Java, or the Enum keyword in Python. Each enumerated value is given a name and a value, and these values can be used in place of literal values in the code.
The primary advantage of using enumerations is that they can make the code more readable and maintainable. For example, instead of using magic numbers or string literals to represent specific values, an enumeration can be used to provide meaningful names for these values. This can make the code easier to understand and less prone to errors, since the intent of the code is made clearer.
5. What is the main difference between Java and C?
Java and C are both programming languages, but they have some significant differences that set them apart. Here are some of the main differences between Java and C:
6. Explain some of the use cases of data structures in real-life scenarios.
There are many use cases for data structures some of them are explained below:
7. What is the difference between arrays and structures?
Arrays and structures are both data structures that can be used to store and organize data in a program, but they have some key differences.
8. Among C and C++ in which language you can use the already written code and how?
You can use existing code in both C and C++, but the way that you reuse the code will depend on the language you’re using.
C: In C, you can use existing code by including header files and linking object files together. You can write header files that define the prototypes of functions that you want to reuse, and then include those header files in your source code. You can also create object files that contain compiled versions of your code, and link those object files together with your main program.
C++: In C++, you can use existing code in much the same way as you can in C, but you also have additional options. For example, you can reuse code in C++ by creating classes and objects. You can write classes that encapsulate your code, and then create objects that use that code. Additionally, you can reuse code in C++ by creating templates and using inheritance. Templates allow you to write generic code that can work with different types, and inheritance allows you to create new classes that inherit the properties and behavior of existing classes.
Both C and C++ provide powerful tools for reusing code, and the choice of which language you use will depend on the specific requirements of your project.
9. What is bubble and insertion sort?
Bubble Sort and Insertion Sort are two algorithms for sorting data in an array or list.
Bubble Sort: Bubble Sort is a simple sorting algorithm that repeatedly steps through the list, compares adjacent elements and swaps them if they are in the wrong order. The algorithm gets its name from the way smaller elements "bubble" to the top of the list. The algorithm continues this process until the list is sorted. Bubble Sort has a time complexity of O(n^2), which makes it inefficient for large lists, but it is easy to understand and implement.
Insertion Sort: Insertion Sort is a simple sorting algorithm that builds the final sorted array one item at a time. It is much less efficient than Bubble Sort, with a time complexity of O(n^2), but it has the advantage of being more efficient than Bubble Sort for smaller lists and partially sorted arrays. In Insertion Sort, the algorithm starts with an empty left-side sub-list and moves elements from the right-side sub-list to the left-side sub-list, one at a time.
10. With reference to C language explain the command line argument.
In the C programming language, command line arguments are a way for a program to accept input from the user at the command line when the program is run. Command line arguments are passed to the program as an array of strings, with each string representing a separate argument.
11. What is the difference between pass-by-value and pass-by-reference?
Here is the explanation of both.
In "pass-by-value," a copy of the argument’s value is passed to the function. The function operates on this copy, and any changes made to the argument within the function have no effect outside of it. In other words, the original argument is not affected by the changes made within the function. This is the default behavior in many programming languages, including C and Java.
In "pass-by-reference," a reference to the argument (i.e., its memory address) is passed to the function. This allows the function to directly modify the original argument. Any changes made to the argument within the function are reflected outside of it. This behavior is supported in many programming languages, including C++ and Python, using pointers or references.
12. What is a pointer with respect to C language?
A pointer is a variable in the C programming language that stores the memory address of another variable. The memory address stored by a pointer is used to access the value stored in the variable pointed to. Pointers are a powerful feature in C, as they allow you to manipulate data stored in memory directly, rather than just through the values of variables.
A pointer variable is declared using the * operator, followed by the type of the variable being pointed to.
13. Differentiate between void pointer and null pointer.
In the C programming language, there are two types of pointers that have a special meaning: the void pointer and the null pointer.
A "void pointer" is a pointer that can point to any type of object, including objects of any data type. It is declared using the keyword void as the data type, and it is often used as a generic pointer type when the type of the object being pointed to is not known or needs to be ignored.
14. In C what are conditional Statements?
In C, conditional statements are used to make decisions based on certain conditions. They allow you to execute different pieces of code depending on whether a certain condition is true or false. There are three types of conditional statements in C: the if statement, the if-else statement, and the switch statement.
15. In C explain memory allocation.
Memory allocation in C refers to the process of assigning blocks of memory dynamically at runtime to store data for a program. In C, you can allocate memory dynamically using two functions from the standard library: malloc and calloc.
The malloc function (short for "memory allocation") is used to allocate a block of memory of a specified size. It takes one argument, which is the size in bytes of the memory block to be allocated. It returns a pointer to the first byte of the newly allocated memory block, or NULL if the allocation fails.
The calloc function (short for "contiguous allocation") is similar to malloc, but it initializes the memory block to zero before returning a pointer to it. It takes two arguments: the number of elements to allocate and the size of each element.
After you have dynamically allocated memory, you are responsible for freeing it when you are done with it, using the free function. Failure to free dynamically allocated memory can result in memory leaks, which can lead to a program running out of memory.
16. What is a debugger in C language?
A debugger in C is a tool that allows you to inspect and control the execution of a C program so that you can identify and fix errors (also known as bugs) in your code. A debugger provides several key features, such as:
17. Explain Memory Alignment.
Memory alignment in C refers to the way data is stored in memory. The process of aligning data in memory is done to optimize memory access speed and reduce memory waste.
Memory alignment means ensuring that the starting address of a data structure is a multiple of a memory alignment boundary, which is a power of two. For example, on a system with a 32-bit word size and an alignment boundary of 4 bytes, an object’s address would be a multiple of 4.
In C, data structures like structures, arrays, and unions can be aligned to specific memory boundaries by using data alignment attributes such as #pragma pack or attribute((aligned(n))), where n is the desired alignment size in bytes.
By default, the compiler will try to align data structures to their natural alignment boundaries, which is the size of their largest data type. For example, if a structure contains a double type, which requires 8-byte alignment on most systems, the compiler will align the structure to an 8-byte boundary.
Proper memory alignment is important for performance, especially when working with large amounts of data, as misaligned memory access can result in slow performance or even crashes.
18. What do you understand by static identifier?
In the C programming language, the static identifier is a keyword that can be used to declare variables, functions, or objects with static storage duration.
A variable declared with static has a fixed storage location in memory and retains its value between function calls. This means that the value of a static variable is preserved across multiple invocations of the function in which it is declared, while non-static (or "automatic") variables are destroyed and re-created each time the function is called.
A static function is a function that can only be called within the same source file in which it is defined. It is not accessible from other files, making it a type of internal linkage. This can be useful for encapsulating implementation details or creating utility functions that are only needed within a specific file.
In the case of objects, the static keyword can be used to declare static class members in C++. These are members that are shared by all objects of a class, as opposed to instance members, which are unique to each object.
19. What are loops in C language?
Loops in C are constructs that allow you to repeatedly execute a block of code a certain number of times or until a specific condition is met. They are a fundamental building block for writing efficient and flexible code. There are two main types of loops in C: for loops, while loops, and do while loops.
20. Difference between struct and enum.
struct and enum are two different constructs in C that serve different purposes.
A struct (structure) is a user-defined data type that allows you to group together variables of different data types under a single name. It provides a way to store multiple pieces of data in a single object, making it easier to manage and organize data in your program.
In this section, we will discuss TCS C Language: Coding Questions. We will discuss some of the coding questions in C language asked in TCS Interview.
1. Write a program in the C language of swapping two numbers by using a third number.