In this blog, we will discuss some common and scenarios based interview questions and answers for C(language). Navigating a job interview can be challenging, especially when it comes to answering technical questions that test your understanding and skills in the C programming language. Whether you’re a fresher entering the job market or an experienced professional looking to switch roles, it’s crucial to be well-prepared.
This comprehensive list of questions and answers is tailored to help you demonstrate your proficiency in C language during interviews. These questions cover a broad range of topics, from basic concepts to more advanced techniques, ensuring you are well-equipped for any C language interview scenario.
Interview questions and answers:
Q: Explain the difference between ‘#include <filename>’ and ‘#include “filename”‘.
A: ‘#include <filename>’ is used for system header files, while ‘#include “filename”‘ is used for user defined header files.
Q: What is the use of the ‘static’ keyword in C?
A: The ‘static’ keyword limits the scope of a variable or function to the file it’s declared in and retains its value between function calls.
Q: How does a ‘for’ loop differ from a ‘while’ loop in C?
A: A ‘for’ loop is typically used when the number of iterations is known, while a ‘while’ loop is preferred when the condition needs to be evaluated each time before the loop executes.
Q: Describe what a pointer is and how to use it?
A: A pointer is a variable that stores the memory address of another variable, allowing for direct memory access and manipulation.
Q: What are the different storage classes in C?
A: The storage classes in C are ‘auto’, ‘register’, ‘static’, and ‘extern’.
Q: How do you dynamically allocate memory in C?
A: Memory can be dynamically allocated using functions like ‘malloc’, ‘calloc’, ‘realloc’, and freed using ‘free’.
Q: Explain the purpose of the ‘const’ keyword in C.
A: The ‘const’ keyword is used to define constants, ensuring that the value of the variable it qualifies cannot be changed.
Q: What is the difference between ‘struct’ and ‘union’ in C?
A: ‘struct’ allocates memory for each member separately, while ‘union’ allocates memory for the largest member and shares it among all members.
Q: What is a null pointer and how is it different from an uninitialized pointer?
A: A null pointer explicitly points to nothing (‘NULL’), while an uninitialized pointer contains a random memory address.
Q: How does the ‘switch’ statement work in C?
A: The ‘switch’ statement evaluates an expression and executes the corresponding ‘case’ block based on the expression’s value.
Q: What is the difference between ‘fgets’ and ‘gets’?
A: ‘fgets’ reads a specified number of characters from a file or input stream, while ‘gets’ reads input until a newline is encountered, leading to potential buffer overflow.
Q: Explain the concept of recursion with an example.
A: Recursion is a programming technique where a function calls itself. For example, calculating factorial using recursion.
Q: How do you create a multidimensional array in C?
A: A multidimensional array can create by specifying multiple dimensions in the array declaration, e.g., ‘int arr[3][4];’.
Q: Describe the difference between ‘++i’ and ‘i++’.
A: ‘++i’ increments the value of ‘i’ before its current value is used, while ‘i++’ uses the current value of ‘i’ before incrementing it.
Q: How do you handle errors in C using ‘errno’?
A: ‘errno’ is a global variable that stores error codes set by system calls and library functions. Functions like ‘strerror’ can be use to interpret these codes.
Q: What is a function pointer, and how to use it?
A: A function pointer stores the address of a function, allowing functions to be passed as arguments or assigned to variables.
Q: How do you use the ‘volatile’ keyword in C?
A: The ‘volatile’ keyword indicates that a variable’s value can be changed unexpectedly, preventing the compiler from optimizing its usage.
Q: What is the purpose of the ‘restrict’ keyword in C?
A: The ‘restrict’ keyword indicates that a pointer is the only way to access the data it points to, allowing for optimization.
Mastering the C programming language is a vital skill for many technical roles, and being able to effectively answer interview questions on this topic can significantly enhance your job prospects. This set of multiple-choice questions and answers aims to provide a thorough review of key concepts and techniques in C, helping you to prepare confidently for your next interview. Remember, practice and understanding are key to success.
Hope you like above interview questions and answers for C(Language). Keep revising, stay updated with the latest developments in the field, and approach each interview with confidence. Good luck! 🚀😊
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