Top 100 C Interview Questions and Answers

Code to find length of string without using strlen() function.

• Use a loop to iterate through each character of the string

• Increment a counter variable for each character in the string

• Stop the loop when the null character '\0' is encountered

• Return the c...read more

C code in Java refers to the use of the Java Native Interface (JNI) to incorporate C code into Java programs.

• C code in Java is typically used when performance optimization or low-level system access is required.

• JNI allows Java programs to call C func...read more

Flow chart for a C program

• Identify the input and output

• Determine the conditions and loops

• Draw the flow chart accordingly

Web development using C involves using frameworks like CGI, FastCGI, or libraries like libmicrohttpd.

• Use frameworks like CGI or FastCGI to handle HTTP requests and responses.

• Utilize libraries like libmicrohttpd for creating web servers in C.

• Implement...read more

Storage classes in C define the scope and lifetime of variables.

• There are four storage classes in C: auto, register, static, and extern.

• Auto variables are local to a block and have automatic storage duration.

• Register variables are stored in CPU regis...read more

Static storage class is used to declare variables that retain their values throughout the program execution.

• Variables declared with static storage class have a lifetime that extends for the entire duration of the program.

• They are initialized only onc...read more

Bit fields are used to allocate specific number of bits in a structure to store and manipulate data efficiently.

• Bit fields are declared using a colon (:) followed by the number of bits to allocate.

• They can be used to represent flags, status bits, or ...read more

There are no classes in C as it is a procedural programming language.

• C is a procedural programming language, not an object-oriented one.

• It does not have the concept of classes or objects.

• Instead, it uses functions and structures to organize code.

• Stru...read more

Here is a simple example of a C program that prints 'Hello, World!'

• Declare a main function

• Use the printf function to print 'Hello, World!'

• Return 0 to indicate successful execution

A simple C program

• Include the stdio.h header file

• Declare the main function

• Use printf() function to print output

• Use scanf() function to take input

• End the program with return 0;

Storage class specifiers in C are used to define the scope and lifetime of variables.

• There are four storage class specifiers in C: auto, register, static, and extern.

• Auto variables are local to a block and have automatic storage duration.

• Register var...read more

Yes, some libraries are required for C programming such as stdio.h, math.h, string.h, etc.

• stdio.h library is used for input/output operations

• math.h library is used for mathematical operations

• string.h library is used for string manipulation operations

Program to implement strcmp

• Use a loop to compare each character of the two strings

• Return 0 if both strings are equal, -1 if s1s2

• Handle null and empty strings appropriately

printf() is used to print formatted output to the screen, while scanf() is used to read formatted input from the user.

• printf() is used to display output on the screen in a formatted way.

• scanf() is used to read input from the user in a formatted way.

• E...read more

In C, 'dynamic' is not a storage class; valid ones include auto, extern, and static.

• Storage classes define the scope, visibility, and lifetime of variables.

• auto: Default storage class for local variables, e.g., 'int x;' inside a function.

• extern: Used...read more

The four storage classes in C are auto, register, static, and extern.

• Auto: default storage class for all local variables

• Register: used to define local variables that should be stored in a register instead of RAM

• Static: used to define local variables ...read more

b) x is four bit integer.

• The statement 'int x:4;' indicates that x is a four bit integer.

• A four bit integer can have values ranging from 0 to 15.

• The colon followed by the number 4 specifies the number of bits allocated for x.

A C program that needs to be written and explained line by line.

• The program should be written in C language.

• Each line of the program needs to be explained.

• The program should use an array of strings.

• The answer should be returned in JSON format.

To start a program in C language, we need to write a main function and compile the code.

• Write the main function with the code to be executed

• Compile the code using a C compiler

• Execute the compiled program

• Optionally, pass command line arguments to the ...read more

Test_and_Set program is used to ensure mutual exclusion in concurrent systems.

• Test_and_Set is a hardware instruction that sets a memory location to a value and returns its old value.

• The program uses a loop to repeatedly execute the Test_and_Set instr...read more

Structure and union are two user-defined data types in C used to store multiple data types under a single variable name.

• Structure is a collection of variables of different data types under a single name.

• Union is similar to structure but all the varia...read more

Delete and free are both used to deallocate memory, but delete is used for objects created with new, while free is used for memory allocated with malloc.

• delete is used in C++ to deallocate memory for objects created with new keyword

• free is used in C ...read more

Static, volatile, const are C keywords used to define properties of variables.

• Static: used to define a variable that retains its value between function calls

• Volatile: used to indicate that a variable's value may change unexpectedly, e.g. in an interr...read more

Main function is required in C program as it is the entry point of the program.

• Main function is where the program starts executing.

• It contains the code that initializes variables, calls functions, and performs other necessary tasks.

• Without main funct...read more

Arr and adr are both used in programming, but arr typically refers to an array while adr typically refers to an address.

• Arr is commonly used to refer to an array in programming, which is a collection of elements stored in a contiguous memory location...read more

The process of converting Example.c file to Example.exe involves several steps.

• Preprocessing: includes header file inclusion, macro expansion, and conditional compilation

• Compilation: converts source code to object code

• Linking: combines object code wi...read more

The founder of C language is Dennis Ritchie.

• Dennis Ritchie is the creator of the C programming language.

• He developed C language at Bell Labs in the early 1970s.

• C language is widely used for system programming and developing other programming language...read more