4.2.1 - introduction to function, Definition and their Prototypes.

1. How are multidimensional arrays stored in memory?

(A) Row-major order
(B) Column-major order
(C) Random order
(D) They cannot be stored in memory

Correct Answer: (A) Row-major order

2. What is the basic type of multiple dimensions array in C?

(A) 2D array
(B) 3D array
(C) 1D array
(D) Array of pointers

Correct Answer: (A) 2D array

3. Which of the following is true about a 2D array in C?

(A) A distinct 1D array can represent each element
(B) Only one row can be declared
(C) Rows and columns must have the same size
(D) 2D arrays are only used for matrices

Correct Answer: (A) A distinct 1D array can represent each element

4. How many loops are needed to traverse a 2D array in C?

(A) 1
(B) 2
(C) 3
(D) 4

Correct Answer: (B) 2

5. Which matrix is called a rectangle matrix in a 2D array?

(A) When rows and columns are equal
(B) When rows are greater than columns
(C) When rows and columns differ
(D) When columns are greater than rows

Correct Answer: (C) When rows and columns differ

6. What is the valid declaration for a 2D array?

(A) int array[][];
(B) int array[3][];
(C) int array[3][4];
(D) int array[];

Correct Answer: (C) int array[3][4];

7. What is the default return type of a C function?

(A) int
(B) void
(C) float
(D) char

Correct Answer: (A) int

8. Which of the following does not return any value?

(A) Procedure
(B) Function
(C) main()
(D) None of the above

Correct Answer: (A) Procedure

9. What is stored in a stack before calling a function?

(A) Arguments
(B) Return address
(C) Local variables
(D) None of the above

Correct Answer: (B) Return address

10. Which of the following components form a function declaration?

(A) Return type, name, parameters
(B) Body of the function
(C) Only the name
(D) None of the above

Correct Answer: (A) Return type, name, parameters

11. What is the correct way to declare a 2D array without specifying the row size?

(A) int array[][3];
(B) int array[3][];
(C) int array[];
(D) int array[][];

Correct Answer: (A) int array[][3];

12. Which of the following will update an element in a 2D array?

(A) Modify the element directly
(B) Scan and replace via loops
(C) Insert at the new position
(D) None of the above

Correct Answer: (B) Scan and replace via loops

13. What is the advantage of using functions in C?

(A) Code duplication
(B) Efficient memory allocation
(C) Less readability
(D) Slower execution

Correct Answer: (B) Efficient memory allocation

14. Which function prototype is valid in C?

(A) int func();
(B) void func(int);
(C) float func(int, char);
(D) All of the above

Correct Answer: (D) All of the above

15. Which of the following allows functions to be reused in C?

(A) Procedures
(B) Subprograms
(C) Function calls
(D) Macros

Correct Answer: (C) Function calls

16. What is a key benefit of subprograms?

(A) Prevent code reuse
(B) Halts the main program
(C) Reduces code repetition
(D) Slows down execution

Correct Answer: (C) Reduces code repetition

17. Which of the following is incorrect about 2D array declaration?

(A) int arr[4][3];
(B) int array[][] = {1,2,3};
(C) int array[][3];
(D) int array[2][3];

Correct Answer: (B) int array[][] = {1,2,3};

18. Which operation is performed first when a function is called?

(A) Stack update
(B) Main function pauses
(C) Subprogram execution
(D) Return address stored

Correct Answer: (D) Return address stored

19. What is matrix multiplication in C?

(A) Adding corresponding elements
(B) Multiplying row of one matrix with column of another
(C) Transposing one matrix
(D) Copying elements

Correct Answer: (B) Multiplying row of one matrix with column of another

20. How many loops are needed for matrix multiplication?

(A) 1
(B) 2
(C) 3
(D) 4

Correct Answer: (C) 3

4.2.2 - Function Arguments and function Call.

21. What is the default return type for a function in C if not specified?

(A) int
(B) void
(C) float
(D) char

Correct Answer: (A) int

22. Which of the following is the correct syntax for declaring a function with an argument but no return type?

(A) int function(int x);
(B) void function(int x);
(C) float function(int x);
(D) char function(int x);

Correct Answer: (B) void function(int x);

23. Which of the following is true about function arguments in C?

(A) Arguments are optional
(B) Functions must always have arguments
(C) Function arguments must be integers
(D) A function cannot return values if it has arguments

Correct Answer: (A) Arguments are optional

24. How are formal parameters handled in a C function?

(A) They are created upon function entry and destroyed upon exit
(B) They are global variables
(C) They persist even after the function ends
(D) They are not necessary for any function

Correct Answer: (A) They are created upon function entry and destroyed upon exit

25. What is the correct syntax for calling a function with an argument in C?

(A) function();
(B) function(x);
(C) function(int);
(D) void function();

Correct Answer: (B) function(x);

26. Which of the following is a valid declaration for a function without arguments and without return value?

(A) void function();
(B) int function();
(C) float function();
(D) char function();

Correct Answer: (A) void function();

27. Which method passes a copy of an argument’s value to a function?

(A) Call by value
(B) Call by reference
(C) Pass by address
(D) Direct pass

Correct Answer: (A) Call by value

28. Which method passes the address of the argument to a function?

(A) Call by value
(B) Call by reference
(C) Call by address
(D) Pass by pointer

Correct Answer: (B) Call by reference

29. What happens to the actual parameter when using Call by Value?

(A) It gets modified
(B) It does not get modified
(C) The actual parameter is deleted
(D) The function accesses the actual parameter directly

Correct Answer: (B) It does not get modified

30. Which of the following languages does not support Call by Reference by default?

(A) C
(B) C++
(C) PHP
(D) Java

Correct Answer: (D) Java

31. Which statement is true for Call by Reference in C?

(A) The actual value is passed to the function
(B) The address of the actual argument is passed
(C) No values are passed
(D) The return type must be void

Correct Answer: (B) The address of the actual argument is passed

32. In which memory area are the local variables, including function arguments, stored in C?

(A) Stack
(B) Heap
(C) Global memory
(D) Data segment

Correct Answer: (A) Stack

33. What is the output of this code snippet?

                void func(int *x) {
                    *x = *x + 10;
                }
                int main() {
                    int y = 5;
                    func(&y);
                    printf("%d", y);
                    return 0;
                }

(A) 5
(B) 10
(C) 15
(D) Error

Correct Answer: (C) 15

34. What will happen when you pass an array to a function in C?

(A) The entire array is passed by value
(B) Only the base address of the array is passed
(C) The first element of the array is passed
(D) An error occurs

Correct Answer: (B) Only the base address of the array is passed

35. Which of the following methods is used to modify a variable inside a function?

(A) Pass by pointer
(B) Pass by value
(C) Call by constant
(D) Call by scope

Correct Answer: (A) Pass by pointer

36. What is required to implement Call by Reference in C?

(A) Pointers
(B) Arrays
(C) Macros
(D) Strings

Correct Answer: (A) Pointers

37. Which of the following functions returns the maximum of two numbers?

(A) max(a, b);
(B) a + b;
(C) int max(int a, int b);
(D) int max(a, b);

Correct Answer: (C) int max(int a, int b);

38. What will be the output of the following code?

                void swap(int a, int b) {
                    int temp = a;
                    a = b;
                    b = temp;
                }
                int main() {
                    int x = 5, y = 10;
                    swap(x, y);
                    printf("%d %d", x, y);
                    return 0;
                }

(A) 10 5
(B) 5 10
(C) Error
(D) Undefined behavior

Correct Answer: (B) 5 10

39. What is the primary difference between Call by Value and Call by Reference?

(A) Call by Value passes a copy, while Call by Reference passes the address
(B) Call by Value passes the address, while Call by Reference passes a copy
(C) Call by Reference requires recursion
(D) Both are the same

Correct Answer: (A) Call by Value passes a copy, while Call by Reference passes the address

40. What does the return statement do in a function?

(A) Ends the function and returns a value to the caller
(B) Ends the program
(C) Skips a loop
(D) Continues the function without returning a value

Correct Answer: (A) Ends the function and returns a value to the caller

4.2.3 - types of Functions.

41. What are the two types of functions in C?

(A) System functions and Library functions
(B) Library functions and User-defined functions
(C) Predefined functions and System functions
(D) Static functions and Dynamic functions

Correct Answer: (B) Library functions and User-defined functions

42. What is another name for a library function in C?

(A) Built-in function
(B) Predefined function
(C) Compiler function
(D) Standard function

Correct Answer: (A) Built-in function

43. Which of the following is a library function?

(A) int max(int, int);
(B) pow();
(C) userFunction();
(D) customFunction();

Correct Answer: (B) pow();

44. What is the main advantage of using library functions in C?

(A) They are automatically included in the code
(B) They do not need to be declared and defined by the programmer
(C) They always execute faster than user-defined functions
(D) They are more secure than user-defined functions

Correct Answer: (B) They do not need to be declared and defined by the programmer

45. Which of the following is an example of a user-defined function?

(A) sqrt()
(B) printf()
(C) myFunction()
(D) strcmp()

Correct Answer: (C) myFunction()

46. What header file is required for the sqrt() function?

(A) stdio.h
(B) math.h
(C) string.h
(D) conio.h

Correct Answer: (B) math.h

47. Which of the following is true for user-defined functions?

(A) They are always faster than library functions
(B) They must be declared and defined by the programmer
(C) They are stored in a separate file
(D) They are part of the compiler package

Correct Answer: (B) They must be declared and defined by the programmer

48. Which function calculates the power of a number in C?

(A) pow()
(B) power()
(C) exp()
(D) sqrt()

Correct Answer: (A) pow()

49. In which of the following situations would you use a user-defined function?

(A) When performing complex mathematical operations
(B) When a specific task needs to be repeated multiple times
(C) When no library function exists for the task
(D) Both B and C

Correct Answer: (D) Both B and C

50. What is the main disadvantage of user-defined functions compared to library functions?

(A) They cannot handle complex tasks
(B) They are less efficient than library functions
(C) They must be manually declared and defined by the programmer
(D) They cannot return a value

Correct Answer: (C) They must be manually declared and defined by the programmer

51. What is the purpose of the #include statement in C?

(A) To define user-defined functions
(B) To include library functions related to mathematical operations
(C) To enable system functions
(D) To optimize program performance

Correct Answer: (B) To include library functions related to mathematical operations

52. Which of the following is true about the function pow() in C?

(A) It is a user-defined function
(B) It takes two arguments and returns the result of the first raised to the power of the second
(C) It calculates the square root of a number
(D) It is defined in stdio.h

Correct Answer: (B) It takes two arguments and returns the result of the first raised to the power of the second

53. Which of the following statements is correct for user-defined functions?

(A) They do not require a return type
(B) They can only return integer values
(C) They can return any data type
(D) They are always void functions

Correct Answer: (C) They can return any data type

54. Which of the following is NOT a C library function?

(A) printf()
(B) strcpy()
(C) calculateArea()
(D) strlen()

Correct Answer: (C) calculateArea()

55. Which function is used to find the square root of a number in C?

(A) pow()
(B) sqrt()
(C) abs()
(D) log()

Correct Answer: (B) sqrt()

56. Which of the following is a major benefit of user-defined functions?

(A) They reduce the overall complexity of a program by allowing code reuse
(B) They automatically optimize program performance
(C) They do not require header files
(D) They are faster than library functions

Correct Answer: (A) They reduce the overall complexity of a program by allowing code reuse

57. What is the output of the following program?

                #include 
                int add(int a, int b) {
                    return a + b;
                }
                int main() {
                    int result = add(3, 4);
                    printf("%d", result);
                    return 0;
                }

(A) 7
(B) 3
(C) 4
(D) Error

Correct Answer: (A) 7

58. What must be true for a function to be considered user-defined?

(A) It must be written by the programmer
(B) It must include only one argument
(C) It must not use any library functions
(D) It must return an integer

Correct Answer: (A) It must be written by the programmer

59. In which scenario would you most likely use a user-defined function instead of a library function?

(A) When performing a common mathematical operation
(B) When implementing custom logic specific to the program
(C) When calling a function from an external library
(D) When requiring high-performance code

Correct Answer: (B) When implementing custom logic specific to the program

60. Which statement about C library functions is false?

(A) They are predefined and part of the C standard library
(B) They must be declared by the user before use
(C) They save development time
(D) They are optimized for performance

Correct Answer: (B) They must be declared by the user before use

4.2.4 - Predefined vs User Defined functions.

61. Which of the following is true about predefined functions?

(A) They need to be defined by the programmer
(B) They are also known as library functions
(C) They cannot be used in C programs
(D) They must always return an integer value

Correct Answer: (B) They are also known as library functions

62. Which of the following is NOT a predefined function in C?

(A) printf()
(B) scanf()
(C) main()
(D) getch()

Correct Answer: (C) main()

63. Which of the following is NOT a part of a user-defined function in C?

(A) Function declaration
(B) Function call
(C) Function name
(D) Header file

Correct Answer: (D) Header file

64. What is the role of the return type in a function definition?

(A) It specifies the name of the function
(B) It specifies the data type of the value the function returns
(C) It specifies the parameters the function takes
(D) It specifies how many times the function will execute

Correct Answer: (B) It specifies the data type of the value the function returns

65. Which keyword is used as a return type if a function does not return any value?

(A) int
(B) void
(C) char
(D) return

Correct Answer: (B) void

66. What is a "parameter" in a function?

(A) A value that is always returned by the function
(B) A placeholder that receives values when the function is called
(C) The return value of the function
(D) A built-in function

Correct Answer: (B) A placeholder that receives values when the function is called

67. What is the main advantage of using user-defined functions?

(A) They are automatically included in the C library
(B) They make the code more readable and reusable
(C) They are always faster than predefined functions
(D) They do not need a function declaration

Correct Answer: (B) They make the code more readable and reusable

68. In a user-defined function, what does the function body contain?

(A) The name of the function
(B) The data type of the return value
(C) The statements that describe what the function does
(D) The parameters of the function

Correct Answer: (C) The statements that describe what the function does

69. What is the correct order for defining a user-defined function in C?

(A) Function call, function declaration, function definition
(B) Function definition, function declaration, function call
(C) Function declaration, function call, function definition
(D) Function declaration, function definition, function call

Correct Answer: (D) Function declaration, function definition, function call

70. Which of the following is an advantage of using functions in C?

(A) They increase code complexity
(B) They improve code reusability and readability
(C) They make the code harder to debug
(D) They cannot return values

Correct Answer: (B) They improve code reusability and readability

71. In the function declaration int add(int, int);, what does int before add signify?

(A) The name of the function
(B) The return type of the function
(C) The parameter types
(D) The number of parameters

Correct Answer: (B) The return type of the function

72. What is the purpose of function declaration in C?

(A) To define the function body
(B) To specify the return type and parameters of the function to the compiler
(C) To execute the function
(D) To repeat code inside the function

Correct Answer: (B) To specify the return type and parameters of the function to the compiler

73. Which of the following can be considered as an example of a user-defined function?

(A) printf()
(B) scanf()
(C) myFunction()
(D) main()

Correct Answer: (C) myFunction()

74. What must be included in the function definition?

(A) The header file
(B) The function body
(C) The return value
(D) The parameters only

Correct Answer: (B) The function body

75. Which of the following is NOT a characteristic of predefined functions?

(A) They are part of the C standard library
(B) They need to be manually defined by the programmer
(C) They save time in development
(D) They are optimized for performance

Correct Answer: (B) They need to be manually defined by the programmer

76. What is the correct syntax for calling a user-defined function named calculate with two integer parameters a and b?

(A) calculate;
(B) calculate(a b);
(C) calculate(a, b);
(D) calculate(a) b;

Correct Answer: (C) calculate(a, b);

77. Which statement about function parameters is true?

(A) A function must always have at least one parameter
(B) The parameters are part of the function name
(C) Parameters are optional; a function can have zero parameters
(D) Parameters cannot have data types

Correct Answer: (C) Parameters are optional; a function can have zero parameters

78. Which of the following is an advantage of using functions in a program?

(A) Functions increase memory usage
(B) Functions reduce the need for repeated code
(C) Functions make debugging harder
(D) Functions are always slower than using raw code

Correct Answer: (B) Functions reduce the need for repeated code

79. Which of the following describes a function call in C?

(A) It defines the function
(B) It declares the function
(C) It executes the function
(D) It specifies the return type of the function

Correct Answer: (C) It executes the function

80. What is the output of the following program?

                #include <stdio.h>
                void greet() {
                    printf("Hello, World!");
                }
                int main() {
                    greet();
                    return 0;
                }

(A) Error
(B) No output
(C) Hello, World!
(D) Undefined

Correct Answer: (C) Hello, World!

4.2.5 - User Defined functions.

81. Which of the following is true about user-defined functions?

(A) They are predefined and cannot be modified
(B) They are modifiable to suit the programmer's needs
(C) They cannot be reused in other programs
(D) They are always faster than library functions

Correct Answer: (B) They are modifiable to suit the programmer's needs

82. What is the benefit of user-defined functions?

(A) They are predefined in the C library
(B) They do not require a return type
(C) They make code easier to understand and maintain
(D) They must use global variables

Correct Answer: (C) They make code easier to understand and maintain

83. Which statement is true about user-defined functions?

(A) User-defined functions cannot take parameters
(B) User-defined functions must always return an integer
(C) User-defined functions can be reused in different programs
(D) User-defined functions must be declared in the C library

Correct Answer: (C) User-defined functions can be reused in different programs

84. What is the output of the following program?

                #include <stdio.h>
                int sum(int a, int b) {
                    return a + b;
                }
                int main() {
                    int a = 10, b = 20;
                    int result = sum(a, b);
                    printf("Sum is: %d", result);
                    return 0;
                }

(A) Error
(B) No output
(C) Sum is: 30
(D) Undefined

Correct Answer: (C) Sum is: 30

85. What is the function signature of the following user-defined function?

                int multiply(int a, int b) {
                    return a * b;
                }

(A) multiply()
(B) int multiply(int, int)
(C) multiply(int, int)
(D) int multiply()

Correct Answer: (B) int multiply(int, int)

86. In a user-defined function, what does the keyword return do?

(A) It ends the program
(B) It ends the function and sends a value back to the calling function
(C) It declares the return type of the function
(D) It declares the parameters of the function

Correct Answer: (B) It ends the function and sends a value back to the calling function

87. Which part of the user-defined function contains the actual code?

(A) Function declaration
(B) Function prototype
(C) Function body
(D) Function header

Correct Answer: (C) Function body

88. In the given code, what is int sum(int a, int b) called?

                int sum(int a, int b) {
                    return a + b;
                }

(A) Function body
(B) Function definition
(C) Function call
(D) Function declaration

Correct Answer: (B) Function definition

89. Which of the following is an advantage of user-defined functions?

(A) They are predefined in the C library
(B) They cannot take arguments
(C) They can reduce code repetition
(D) They do not need a return type

Correct Answer: (C) They can reduce code repetition

90. Which of the following correctly calls a function named add with arguments 5 and 10?

(A) add(5 10);
(B) add(5, 10);
(C) add();
(D) add(5,10)

Correct Answer: (B) add(5, 10);

91. What is the output of the following code?

                #include <stdio.h>
                int multiply(int a, int b) {
                    return a * b;
                }
                int main() {
                    int x = 5, y = 6;
                    int result = multiply(x, y);
                    printf("Product is: %d", result);
                    return 0;
                }

(A) Product is: 11
(B) Product is: 30
(C) Product is: 56
(D) Product is: 25

Correct Answer: (B) Product is: 30

92. Which of the following is necessary when defining a user-defined function?

(A) Declaring the function inside main()
(B) Defining the function before using it
(C) Returning a value of type void
(D) Using global variables

Correct Answer: (B) Defining the function before using it

4.2.6 - Recursion.

93. What is a user-defined function in C?

(A) A function provided by the C library
(B) A function created by the programmer
(C) A function with no parameters
(D) A function that automatically executes

Correct Answer: (B) A function created by the programmer

94. Which of the following is a valid syntax for a function declaration in C?

(A) int function()
(B) int function
(C) function int()
(D) void return()

Correct Answer: (A) int function()

95. What does the keyword 'void' indicate in a function declaration?

(A) The function does not return any value
(B) The function returns an integer
(C) The function has no parameters
(D) The function has no body

Correct Answer: (A) The function does not return any value

96. What is the default return type of a function in C?

(A) int
(B) float
(C) char
(D) void

Correct Answer: (A) int

97. What is recursion?

(A) A function calling itself
(B) A function calling other functions
(C) A function that does not return a value
(D) A function without any parameters

Correct Answer: (A) A function calling itself

98. Which of the following problems is best solved using recursion?

(A) Loop-based counting
(B) Sorting large datasets
(C) Calculating factorial
(D) Printing a string

Correct Answer: (C) Calculating factorial

99. Which of the following is an example of a library function in C?

(A) printf()
(B) userFunction()
(C) main()
(D) func()

Correct Answer: (A) printf()

100. What is the output of the following code?

                int main() {
                    int x = 5;
                    printf("%d", fact(x));
                    return 0;
                }
                int fact(int n) {
                    if (n == 0)
                        return 1;
                    else
                        return n * fact(n - 1);
                }

(A) 120
(B) 24
(C) 5
(D) 0

Correct Answer: (A) 120

101. What is the key difference between call by value and call by reference?

(A) Call by value passes a copy; call by reference passes the address
(B) Call by reference passes a copy; call by value passes the address
(C) Call by value and call by reference are the same
(D) Call by value changes the original variable

Correct Answer: (A) Call by value passes a copy; call by reference passes the address

102. Which of the following function types does not return any value?

(A) int
(B) void
(C) float
(D) double

Correct Answer: (B) void

103. Which of the following is necessary for recursion to work properly?

(A) Infinite calls
(B) Base case
(C) For loop
(D) Exit condition

Correct Answer: (B) Base case

104. Which of the following is true about recursion?

(A) It requires more memory than an iterative solution
(B) It always executes faster than loops
(C) Recursion and loops perform equally
(D) Recursion is always better than iteration

Correct Answer: (A) It requires more memory than an iterative solution

105. In C, which header file is required to use the library function pow()?

(A) stdio.h
(B) math.h
(C) string.h
(D) stdlib.h

Correct Answer: (B) math.h

106. What is a function prototype in C?

(A) A blueprint of a function
(B) A recursive function
(C) A user-defined function
(D) An undefined function

Correct Answer: (A) A blueprint of a function

107. What is the termination condition in recursion called?

(A) Recursive case
(B) Base case
(C) Stop point
(D) Function body

Correct Answer: (B) Base case

108. Which function call method allows the actual value to remain unchanged in the calling function?

(A) Call by value
(B) Call by reference
(C) Call by pointer
(D) Call by argument

Correct Answer: (A) Call by value

109. Which of the following library functions is used to find the length of a string?

(A) strlen()
(B) strcpy()
(C) strcmp()
(D) strcat()

Correct Answer: (A) strlen()

110. What happens if a recursive function lacks a base case?

(A) Infinite recursion
(B) It terminates immediately
(C) It throws a compile-time error
(D) It returns a null value

Correct Answer: (A) Infinite recursion

111. Which type of variable stores the return address of the function call in recursion?

(A) Stack
(B) Heap
(C) Queue
(D) Linked List

Correct Answer: (A) Stack

112. What is the primary advantage of recursion over iteration?

(A) Simplicity and clarity in solving complex problems
(B) Faster execution time
(C) Uses less memory
(D) Easier to debug

Correct Answer: (A) Simplicity and clarity in solving complex problems

4.2.7 - Function With Variable Number of Argument.

113. What is a function in C programming?

(A) A block of code performing a specific task
(B) A type of variable
(C) A file handler
(D) A preprocessor directive

Correct Answer: (A) A block of code performing a specific task

114. Which of the following is a built-in function in C?

(A) main()
(B) printf()
(C) sum()
(D) scanf()

Correct Answer: (B) printf()

115. Which header file is required for using printf() and scanf() functions?

(A) stdlib.h
(B) stdio.h
(C) conio.h
(D) string.h

Correct Answer: (B) stdio.h

116. Which function call method allows the actual value to remain unchanged in the calling function?

(A) Call by value
(B) Call by reference
(C) Call by pointer
(D) Call by argument

Correct Answer: (A) Call by value

117. Which function in C is used to allocate memory dynamically?

(A) malloc()
(B) printf()
(C) calloc()
(D) free()

Correct Answer: (A) malloc()

118. In C, which keyword is used to declare a function returning no value?

(A) void
(B) int
(C) return
(D) char

Correct Answer: (A) void

119. What is the default return type of a function in C if no return type is explicitly declared?

(A) int
(B) void
(C) float
(D) char

Correct Answer: (A) int

120. How many times can the main() function be called in a C program?

(A) Only once
(B) Twice
(C) Multiple times
(D) Depends on the compiler

Correct Answer: (A) Only once

121. Which function is used to compare two strings in C?

(A) strcmp()
(B) strcat()
(C) strcpy()
(D) strrev()

Correct Answer: (A) strcmp()

122. Which of the following is the correct syntax to declare a function in C?

(A) return_type function_name(parameter list);
(B) function_name(parameter list): return_type;
(C) return_type (parameter list) function_name;
(D) parameter list return_type function_name;

Correct Answer: (A) return_type function_name(parameter list);

123. Which of these is a valid function declaration in C?

(A) int sum();
(B) void sum;
(C) return sum();
(D) int sum(int);

Correct Answer: (D) int sum(int)

124. Which function would you use to find the length of a string in C?

(A) strlen()
(B) strcat()
(C) strcpy()
(D) strcmp()

Correct Answer: (A) strlen()

125. What is recursion in C?

(A) A function calling itself
(B) A function calling another function
(C) A function without parameters
(D) A function that returns a pointer

Correct Answer: (A) A function calling itself

126. Which of the following functions can change the value of the actual parameters passed to it?

(A) Call by value
(B) Call by reference
(C) Call by array
(D) Call by variable

Correct Answer: (B) Call by reference

127. Which function is used to open a file in C?

(A) fopen()
(B) close()
(C) read()
(D) fwrite()

Correct Answer: (A) fopen()

128. What is the return type of the malloc() function in C?

(A) void*
(B) int
(C) char
(D) float

Correct Answer: (A) void*

129. Which C function is used to get the length of an array?

(A) sizeof()
(B) length()
(C) array_length()
(D) strlen()

Correct Answer: (A) sizeof()

130. Which function is used to release the memory allocated dynamically in C?

(A) free()
(B) delete()
(C) malloc()
(D) deallocate()

Correct Answer: (A) free()

131. Which of the following is a function that does not return any value?

(A) void function()
(B) int function()
(C) char function()
(D) float function()

Correct Answer: (A) void function()

132. What does the return keyword do in a function?

(A) It exits the function and returns a value
(B) It prints a value
(C) It allocates memory
(D) It defines the function's name

Correct Answer: (A) It exits the function and returns a value