C Language MCQ Questions and Answers

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

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

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

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

C. Unix. C was initially developed to rewrite the Unix operating system.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

B. Returns true if both operands are true.

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

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

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

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

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

C. if. The if statement allows for conditional execution of code.

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

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

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

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

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

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

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

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

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

C. Nested loop. Nested loops allow for more complex iterative processes.

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

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

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

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.

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

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

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

B. Local variable. Local variables have function-level scope.

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

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

B. Modular programming. This approach improves code organization and reusability.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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.

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

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

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

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

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

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

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

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

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.

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.

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.

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