C Language MCQ Questions and Answers

Correct Answer: B. B. C was derived from the B programming language, which itself was influenced by BCPL.

Correct Answer: C. Dennis Ritchie. Dennis Ritchie developed C at Bell Labs in the early 1970s.

Correct Answer: A. The C Programming Language. This book, written by Brian Kernighan and Dennis Ritchie, became a definitive guide for C programmers.

Correct Answer: C. C++11. This is a standard for the C++ programming language, not C.

Correct Answer: C. Unix. C was initially developed to rewrite the Unix operating system.

Correct Answer: C. Procedural. C programs are structured around procedures or functions that perform specific tasks.

Correct Answer: C. Portability. C code can be compiled and run on various platforms with little or no modification.

Correct Answer: C. Functions. Functions encapsulate blocks of code that can be reused multiple times within a program.

Correct Answer: C. Provides low-level access to hardware. This allows for direct manipulation of memory and system resources.

Correct Answer: B. Compiled. C code is translated into machine code by a compiler before execution.

Correct Answer: A. High-level abstraction. While C provides some abstraction, it is generally considered a lower-level language compared to languages like Java or Python.

Correct Answer: B. Compilation. A compiler translates the human-readable C code into machine code that the computer can understand.

Correct Answer: C. GCC. GCC (GNU Compiler Collection) is a widely used compiler for C and other languages.

Correct Answer: C. To combine object files and libraries into an executable. The linker resolves references between different code modules.

Correct Answer: C. .c. C source code files are typically saved with the .c extension.

Correct Answer: C. Web browser. While a web browser might be used for accessing documentation, it’s not a core component of the development environment itself.

Correct Answer: C. Writing the source code in a text editor. You need to write the C code before you can compile or run it.

Correct Answer: C. gcc. The gcc command invokes the GNU Compiler Collection to compile C code.

Correct Answer: B. main(). The main() function is where the program’s execution begins.

Correct Answer: B. To define functions, variables, and macros. Header files provide declarations and definitions that can be used in multiple source files.

Correct Answer: C. #include. The #include directive tells the preprocessor to insert the contents of a header file into the source code.

Correct Answer: D. printf(). The printf() function is used for formatted output to the console.

Correct Answer: B. To improve code readability and provide explanations. Comments are ignored by the compiler and serve as documentation for humans.

Correct Answer: A. //. Two forward slashes (//) mark the beginning of a single-line comment.

Correct Answer: B. To read input from the user. The scanf() function is used for formatted input from the console.

Correct Answer: C. float. float is a floating-point data type, used for representing numbers with decimal points.

Correct Answer: B. char. The char data type is used to store individual characters like ‘A’, ‘b’, or ‘?’.

Correct Answer: C. To indicate the absence of a value or type. void is often used for functions that do not return a value.

Correct Answer: A. int age;. The syntax for variable declaration is data_type variable_name;

Correct Answer: C. Initialization. For example, int age = 25; initializes the age variable to 25.

Correct Answer: B. Constants. Constants are fixed values that remain the same throughout the program.

Correct Answer: B. const. The const keyword is used to declare a constant, e.g., const int MAX_VALUE = 100;

Correct Answer: C. RAM. Variables are stored in RAM (Random Access Memory) for fast access during program execution.

Correct Answer: A. +. The plus symbol (+) is the addition operator.

Correct Answer: B. Returns the remainder of a division operation. For example, 10 % 3 would result in 1.

Correct Answer: B. ==. The double equals sign (==) is the equality operator.

Correct Answer: B. Returns true if both operands are true.

Correct Answer: C. ^. The caret symbol (^) is the bitwise XOR operator.

Correct Answer: B. To assign a value to a variable. For example, age = 30; assigns the value 30 to the variable age.

Correct Answer: B. Precedence. Operators with higher precedence are evaluated before operators with lower precedence.

Correct Answer: A. Casting. For example, (int)3.14 would convert the floating-point number 3.14 to an integer.

Correct Answer: D. Declarative. Declarative is a programming paradigm, not a type of operator.

Correct Answer: C. if. The if statement allows for conditional execution of code.

Correct Answer: A. else. The else block is executed when the if condition is false.

Correct Answer: C. If-else ladder. This structure allows for multiple conditions to be checked sequentially.

Correct Answer: D. switch. The switch statement provides a way to choose between multiple cases based on a value.

Correct Answer: C. break. The break statement is used to prevent fall-through to the next case.

Correct Answer: B. To provide a catch-all block of code if no other case matches.

Correct Answer: A. for. The for loop is ideal for situations where the number of iterations is predetermined.

Correct Answer: B. Condition. The condition is evaluated before each iteration; if it’s true, the loop continues.

Correct Answer: B. while. The while loop repeatedly executes its code block as long as the specified condition is true.

Correct Answer: B. A do-while loop always executes at least once. The condition is checked after the loop body executes.

Correct Answer: C. Nested loop. Nested loops allow for more complex iterative processes.

Correct Answer: C. break. The break statement terminates the loop and transfers execution to the code following the loop.

Correct Answer: B. Skips the current iteration and proceeds to the next. continue jumps to the next iteration of the loop.

Correct Answer: B. A declaration of a function that specifies its name, return type, and parameters.

Correct Answer: D. The data type of the return value (e.g., int, float). This indicates the type of value the function will send back to the caller.

Correct Answer: B. Argument passing. Arguments are the values provided to a function when it’s called.

Correct Answer: B. return. The return statement sends a value back to the calling function.

Correct Answer: A. Scope. A variable’s scope determines where in the code it can be used.

Correct Answer: B. Local variable. Local variables have function-level scope.

Correct Answer: B. Recursive function. Recursion involves a function calling itself to solve a problem.

Correct Answer: D. Performing simple arithmetic operations. Recursion is typically used for more complex tasks that can be broken down into smaller, self-similar subproblems.

Correct Answer: B. Modular programming. This approach improves code organization and reusability.

Correct Answer: C. Improved code readability and maintainability. Functions make code easier to understand, debug, and modify.

Correct Answer: B. Top-down design. This method helps in organizing complex programs by starting with the overall structure and refining it step by step.

Correct Answer: C. Stepwise refinement. This technique involves breaking down a problem into smaller steps and implementing them in a systematic way.

Correct Answer: B. To organize function declarations and make them accessible to multiple source files. This promotes code reusability and reduces redundancy.

Correct Answer: C. Array. Arrays provide a way to store multiple values of the same type under a single name.

Correct Answer: C. By their indices (positions). Array indices start from 0.

Correct Answer: B. Using loops. Loops provide a convenient way to iterate through array elements.

Correct Answer: C. Multidimensional array. These arrays have rows and columns (or more dimensions).

Correct Answer: C. By pointer. When passing an array to a function, you’re actually passing a pointer to its first element.

Correct Answer: C. 4. Array indices start from 0, so the last element in a 5-element array has an index of 4.

Correct Answer: B. As arrays of characters. A string is a sequence of characters terminated by a null character (‘\0’).

Correct Answer: C. \0. The null character signals the end of the string.

Correct Answer: C. strlen(). The strlen() function returns the number of characters in a string (excluding the null terminator).

Correct Answer: A. strcpy(). The strcpy() function copies the contents of one string to another.

Correct Answer: B. strcat(). The strcat() function appends one string to the end of another.

Correct Answer: B. String literal. For example, “Hello, world!” is a string literal.

Correct Answer: C. Pointer. Pointers provide a way to indirectly access and manipulate data.

Correct Answer: B. *. The asterisk (*) is used in pointer declarations.

Correct Answer: B. Dereferencing. The dereference operator (*) is used to access the value.

Correct Answer: D. All of the above. Pointer arithmetic includes operations like adding or subtracting integers from pointers.

Correct Answer: D. All of the above. There’s a close connection between pointers and arrays in C.

Correct Answer: B. The value of the integer that ptr points to. Dereferencing the pointer gives you the value it points to.

Correct Answer: D. Both B and C. Passing by reference in C is achieved using pointers.

Correct Answer: A. It allows you to modify the original values of variables passed as arguments. This is because the function receives the memory address of the variable.

Correct Answer: B. Yes, functions can return pointers to any data type. This can be useful for returning dynamically allocated memory or pointers to structures.

Correct Answer: B. Dynamic memory allocation. This allows you to allocate memory as needed while the program is running.

Correct Answer: D. All of the above. malloc() allocates a block of memory, calloc() allocates and initializes it to zero, and realloc() resizes an existing block.

Correct Answer: B. free(). It’s important to free dynamically allocated memory to prevent memory leaks.

Correct Answer: B. Structure. Structures allow you to create complex data types by combining variables of various types.

Correct Answer: A. . (dot operator). For example, if you have a structure student with a member name, you would access it as student.name.

Correct Answer: B. Yes, structures can be passed by value or by reference (using pointers). This allows you to work with complex data structures within functions.

Correct Answer: B. Nested structure. Nesting structures provides a way to create hierarchical data organizations.

Correct Answer: A. A data type that groups variables of different data types, where all members share the same memory location. This means that only one member of a union can hold a value at a time.

Correct Answer: C. Members of a union share the same memory location, while members of a structure do not. This makes unions more memory-efficient in certain situations.

Correct Answer: A. Storing data that can have different interpretations (e.g., a value that can be treated as an integer or a float). Unions can be used when you need to store different types of data in the same memory location, but only one type at a time.

Correct Answer: B. fopen(). This function opens a file and returns a file pointer that can be used for subsequent file operations.