1. What is a structure in C?

• A) A data type that holds a single value
• B) A user-defined data type that can hold multiple values of different types
• C) A reserved keyword
• D) A collection of functions

2. Which keyword is used to define a structure in C?

• A) struct
• B) union
• C) enum
• D) class

3. How do you access members of a structure?

• A) Using the * operator
• B) Using the . operator and -> operator
• C) Using the & operator
• D) Using the | operator

4. What does the following code declare?

struct stud {
                    char name[80];
                    int roll;
                    float mark;
                };

• A) A structure with members of the same type
• B) A union
• C) A structure with three different members
• D) An enumeration

5. What will be the output of this code?

struct stud {
                    char name[80];
                    int roll;
                    float mark;
                } st;
                
                st.roll = 100;
                printf("%d", st.roll);

• A) 0
• B) 100
• C) Garbage value
• D) Compilation error

6. How can you define a structure variable without giving it a name?

• A) struct stud st;
• B) struct { char name[80]; int roll; } st;
• C) struct stud;
• D) struct stud {};

7. What does the sizeof operator return when used with a structure?

• A) The size of the first member
• B) The size of the entire structure
• C) The size of the pointer to the structure
• D) The size of each member

8. Which of the following correctly defines a function that takes a structure as an argument?

• A) void printStud(struct stud s);
• B) void printStud(struct *s);
• C) void printStud(struct stud *s);
• D) Both A and C

9. What will happen if you try to access a member of a structure through a null pointer?

• A) The program will work correctly
• B) It will cause a segmentation fault
• C) It will print a random value
• D) It will result in a compile-time error

10. How do you return a structure from a function?

• A) By passing a pointer to the structure
• B) By returning the structure directly
• C) Both A and B
• D) You cannot return a structure from a function

11. Which operator is used to access structure members through a pointer?

• A) . (dot)
• B) * (dereference)
• C) -> (arrow)
• D) & (address)

12. What is the output of the following code?

struct Point {
                    int x;
                    int y;
                };
                
                struct Point p = {3, 4};
                printf("%d", p.x);

• A) 4
• B) 3
• C) 0
• D) Compilation error

13. What type of variable is created when defining a structure without a name?

• A) A global variable
• B) A local variable
• C) An unnamed structure variable
• D) A pointer variable

14. What is the primary use of using structures in C?

• A) To group related data
• B) To create dynamic memory
• C) To perform mathematical calculations
• D) To create an infinite loop

15. How can you initialize a structure in C?

• A) By assigning values directly
• B) Using a constructor
• C) Through a function only
• D) You cannot initialize a structure

16. What will be the output of this code?

struct stud {
                    char name[80];
                    int roll;
                    float mark;
                } s1 = {"John", 101, 85.5};
                
                printf("%s", s1.name);

• A) 0
• B) John
• C) Compilation error
• D) It will print garbage value

17. Which of the following can be a member of a structure?

• A) int, float, char arrays
• B) another structure
• C) pointers
• D) All of the above

18. Which statement is true regarding unions and structures?

• A) Unions use more memory than structures
• B) Structures can hold different types of data, while unions hold one type
• C) Structures can only hold integers
• D) Unions can have only one member

19. How do you define a structure with a member that is another structure?

• A) struct outer { struct inner; };
• B) struct outer { struct inner innerStruct; };
• C) struct outer { struct inner(); };
• D) struct outer { inner; };

20. What is the default access specifier for structure members in C?

• A) public
• B) private
• C) protected
• D) There are no access specifiers in C

21. What is an array in C?

• A) A collection of elements of the same data type
• B) A collection of elements of different data types
• C) A single variable that holds one value
• D) A reserved keyword

22. What is a structure in C?

• A) A collection of elements of the same data type
• B) A collection of elements of different data types
• C) A single variable that holds one value
• D) A reserved keyword

23. How do you access an array element?

• A) Using the . operator
• B) Using the -> operator
• C) Using the [] operator
• D) Using the & operator

24. How do you access a structure member?

• A) Using the [] operator
• B) Using the . operator or -> operator
• C) Using the & operator
• D) Using the * operator

25. Can an array hold elements of different data types?

• A) Yes
• B) No
• C) Only if the elements are pointers
• D) Only in a structure

26. Can a structure hold an array as a member?

• A) Yes
• B) No
• C) Only if the array is of fixed size
• D) Only if the structure is dynamic

27. What is the default size of an array in C?

• A) 1
• B) 10
• C) Depends on the type of data stored
• D) There is no default size

28. How do you declare a structure that includes an array?

• A) struct { int arr[10]; } myStruct;
• B) struct myStruct { int arr[]; };
• C) struct myStruct { int arr; };
• D) struct myStruct { int arr[10]; };

29. What happens if you access an out-of-bounds index in an array?

• A) It will cause a compile-time error
• B) It will print garbage value
• C) It will crash the program
• D) The program will work correctly

30. What happens if you access a member of a structure that is not initialized?

• A) It will print a default value
• B) It will print garbage value
• C) It will cause a segmentation fault
• D) It will cause a compile-time error

31. How do you define an array of structures?

• A) struct stud arr[10];
• B) struct stud *arr;
• C) struct { struct stud arr[10]; }
• D) struct arr[10] { stud; };

32. Which of the following can be members of a structure?

• A) Another structure
• B) Arrays
• C) Pointers
• D) All of the above

33. How do you initialize an array of integers with 5 elements?

• A) int arr[5] = {1, 2, 3, 4, 5};
• B) int arr = {1, 2, 3, 4, 5};
• C) int arr[5] = (1, 2, 3, 4, 5);
• D) int arr[5]; arr = {1, 2, 3, 4, 5};

34. Can a structure contain another structure?

• A) Yes
• B) No
• C) Only if it’s a pointer to another structure
• D) Only in dynamic memory

35. Which has a fixed size: array or structure?

• A) Array
• B) Structure
• C) Both have fixed sizes
• D) Neither have fixed sizes

36. What is the size of a structure with two int members?

• A) 2 bytes
• B) 4 bytes
• C) 8 bytes
• D) Depends on the compiler and architecture

37. What is the output of this code?

                    struct stud {
                        int roll;
                        char name[20];
                    } student = {101, "Alice"};
                    
                    printf("%d", student.roll);
                

• A) Alice
• B) 0
• C) 101
• D) Compilation error

38. Can you use an array in a function as a parameter?

• A) Yes
• B) No
• C) Only if it’s a pointer
• D) Only if it’s a global array

39. How do you pass a structure to a function?

• A) By value
• B) By reference
• C) Both A and B
• D) You cannot pass a structure to a function

40. Which is more memory efficient for storing multiple related data of the same type?

• A) Structure
• B) Array
• C) Union
• D) Both have the same efficiency

41. What is a nested structure in C?

• A) A structure that contains an array
• B) A structure that contains another structure
• C) A structure with no members
• D) A structure that can be declared without a name

42. How do you access a member of a nested structure?

• A) Using the -> operator only
• B) Using the . operator twice
• C) Using the [] operator
• D) Using the & operator

43. What is the purpose of using nested structures?

• A) To create arrays within structures
• B) To combine related data types into a single structure
• C) To avoid using functions
• D) To simplify variable names

44. How do you declare a nested structure?

• A) struct outer { struct inner { int a; }; };
• B) struct outer { int a; struct inner; };
• C) struct outer { struct inner { int a; }; inner b; };
• D) struct outer { struct inner; };

45. What happens if you access a member of a nested structure that is not initialized?

• A) It prints a default value
• B) It prints garbage value
• C) It causes a segmentation fault
• D) It causes a compile-time error

46. Which operator is used to access members of a nested structure?

• A) []
• B) ->
• C) .
• D) &

47. Can a structure member itself be a nested structure?

• A) Yes
• B) No
• C) Only if it is an array
• D) Only if it is a pointer

48. How do you define a nested structure in a function?

• A) You cannot define nested structures in functions
• B) By using the same syntax as outside the function
• C) By using an array inside the structure
• D) By declaring the nested structure first

49. How can you initialize a nested structure?

• A) struct outer o = {1, {2}};
• B) struct outer o = {1, 2};
• C) struct outer o; o.inner = 2;
• D) struct outer o; o.inner.a = 2;

50. In a nested structure, which keyword is used to define an inner structure?

• A) struct
• B) inner
• C) typedef
• D) union

51. What is the output of the following code?

                        struct emp {
                            char name[50];
                            struct dept {
                                int sal;
                                char degi[50];
                            } d;
                        };
                        struct emp e = {"Alice", {50000, "Manager"}};
                        printf("%s %d", e.name, e.d.sal);
                

• A) Alice 0
• B) Alice 50000
• C) 0 50000
• D) Manager Alice

52. Can a structure contain a pointer to another structure?

• A) Yes
• B) No
• C) Only if it’s a nested structure
• D) Only in dynamic memory

53. What is the correct way to declare a variable of a nested structure?

• A) struct outer o;
• B) struct inner i;
• C) struct outer { struct inner; } o;
• D) struct inner o;

54. What keyword is used to define a structure?

• A) class
• B) struct
• C) union
• D) typedef

55. How do you access the designation of an employee in a nested structure?

• A) e.d.degi
• B) e->d.degi
• C) e.d->degi
• D) e->d->degi

56. Which of the following statements is true about nested structures?

• A) They can only contain primitive data types
• B) They can contain arrays and other structures
• C) They cannot contain other structures
• D) They are not allowed in C

57. What is the size of a structure that contains two int members and one char member?

• A) 4 bytes
• B) 8 bytes
• C) 12 bytes
• D) Depends on the compiler and architecture

58. How can you pass a nested structure to a function?

• A) By reference only
• B) By value only
• C) Both by reference and by value
• D) You cannot pass nested structures to functions

59. How do you declare a structure with a nested structure and an array?

• A) struct outer { struct inner { int a; } b; int arr[10]; };
• B) struct outer { struct inner b; int arr[10]; };
• C) struct outer { int arr[10]; struct inner; };
• D) Both A and B

60. Can you use a nested structure to represent a complex data type such as a student with courses?

• A) Yes
• B) No
• C) Only if you use arrays
• D) Only if the courses are defined as enums

61. What is an array of structures in C?

• A) An array containing basic data types
• B) An array containing similar structure data types
• C) An array containing only one structure type
• D) An array containing dissimilar data types

62. How do you declare an array of structures?

• A) struct name[size];
• B) struct name[];
• C) struct name variable[size];
• D) struct name variable;

63. Which of the following is true about the members of a structure?

• A) All members must be of the same data type
• B) Members can be of different data types
• C) Members cannot be arrays
• D) Members must be initialized at declaration

64. What is the output of the following code snippet?

                    struct student {
                        char name[20];
                        int roll;
                    };
                    struct student s[2] = {{"Alice", 1}, {"Bob", 2}};
                    printf("%s", s[0].name);
                

• A) Bob
• B) Alice
• C) 1
• D) 2

65. What does the fflush(stdin) function do in the context of input?

• A) It clears the entire console
• B) It clears the input buffer
• C) It flushes the output buffer
• D) It is not a standard function

66. What is the purpose of passing structures to functions?

• A) To modify global variables
• B) To enable access to structure members
• C) To create a new structure
• D) To create local copies of structure data

67. How can you pass a structure to a function by reference?

• A) By using the address of the structure
• B) By using the structure variable directly
• C) By using a pointer to the structure
• D) Both A and C

68. In the context of structures, what does getch() do?

• A) Reads a character from the standard input
• B) Returns the next character from standard input
• C) Waits for a key press
• D) Both B and C

69. What will be the output of this code?

                            struct stud {
                                char name[20];
                                int roll;
                            };
                            struct stud s = {"Alice", 1};
                            printf("%d", s.roll);
                

• A) Alice
• B) 1
• C) Roll
• D) Name

70. How do you access a member of a structure within an array?

• A) array[index].member
• B) array->member
• C) array.member[index]
• D) array[index]->member

71. Which of the following statements is true about structure members?

• A) They are stored in non-contiguous memory
• B) They can only be of one data type
• C) They can be public or private
• D) They are stored in contiguous memory locations

72. What happens if you try to access an uninitialized member of a structure?

• A) It will return 0
• B) It will cause a compilation error
• C) It will return garbage value
• D) It will return NULL

73. Can a structure contain another structure as a member?

• A) Yes
• B) No
• C) Only if the inner structure is an array
• D) Only if the outer structure is a pointer

74. Which of the following is a valid way to declare a structure variable?

• A) struct student s;
• B) struct student;
• C) student s;
• D) struct student s[];

75. What is a self-referential structure?

• A) A structure that contains an array of itself
• B) A structure that contains a pointer to itself
• C) A structure with no members
• D) A structure containing another structure

76. Which statement about structure members is correct?

• A) They can have private access
• B) They can be static
• C) They are public by default
• D) They cannot be accessed outside the structure

77. Which function is used to read a string from the standard input?

• A) scanf()
• B) gets()
• C) fgets()
• D) Both B and C

78. How do you display the entire content of an array of structures?

• A) By using a single printf statement
• B) By using a loop to access each member
• C) By using a pointer
• D) You cannot display arrays of structures

79. What happens when a structure is passed by value to a function?

• A) The original structure is modified
• B) A copy of the structure is created
• C) Memory is not allocated
• D) It causes a runtime error

80. Which of the following is an advantage of using structures?

• A) They increase the complexity of the code
• B) They allow grouping of related data
• C) They can only store one type of data
• D) They do not allow nesting

81. What happens when a structure variable is passed to a function in C?

• A) The original structure is modified
• B) A copy of the structure is passed to the function
• C) The function cannot access the structure
• D) It causes a compilation error

82. How do you define a structure in C?

• A) struct name{...};
• B) struct name;
• C) name struct{...};
• D) struct name[];

83. In the given program, what is the type of the member "name" in the "student" structure?

• A) char
• B) char[]
• C) char *
• D) string

84. What does the display() function do in the provided code?

• A) Modifies the structure members
• B) Displays the structure member values
• C) Returns a modified structure
• D) Accepts multiple structures

85. Which operator is used to access the members of a structure?

• A) ->
• B) .
• C) *
• D) &

86. How can you ensure that a pointer to a character in a structure points to valid memory?

• A) By assigning a literal string
• B) By using dynamic memory allocation
• C) Both A and B
• D) It cannot be done

87. In the function call display(o);, what does o represent?

• A) A pointer to a structure
• B) The structure itself
• C) The address of the structure
• D) A function

88. What will be the output of the given program?

                    struct student {
                        char *name;
                        int age;
                        float per;
                    };
                    struct student o = {"RAM", 25, 75.5};
                    display(o);
                

• A) Name: 25, Age: RAM, Percent: 75.5
• B) Name: RAM, Age: 25, Percent: 75.5
• C) Name: RAM, Age: 75.5, Percent: 25
• D) None of the above

89. What does the return 0; statement indicate in the main() function?

• A) The program has errors
• B) The program completed successfully
• C) The program is still running
• D) The program is terminating

90. If the structure is modified in the display() function, what happens to the original structure in the main() function?

• A) It is modified
• B) It remains unchanged
• C) It will cause a runtime error
• D) It will be deleted

91. What is the purpose of using a pointer for the "name" member in the structure?

• A) To save memory
• B) To allow dynamic allocation of memory
• C) To avoid copying large strings
• D) All of the above

92. Which of the following statements is true about passing structures to functions?

• A) Structures are passed by reference by default
• B) Structures are passed by value by default
• C) Structures cannot be passed to functions
• D) Functions can only accept primitive data types

93. Can a function return a structure in C?

• A) Yes
• B) No
• C) Only if it’s a pointer
• D) Only if the structure has less than 5 members

94. What is the output of the following code snippet?

                    struct student {
                        char *name;
                        int age;
                        float per;
                    };
                    struct student o = {"Alice", 22, 88.5};
                    printf("%s", o.name);
                

• A) Alice
• B) 22
• C) 88.5
• D) None of the above

95. What will happen if you try to print an uninitialized pointer member in a structure?

• A) It will print NULL
• B) It will cause a segmentation fault
• C) It will print garbage value
• D) It will print an empty string

96. What does the printf() function do in the display() function?

• A) Reads input from the user
• B) Displays output to the console
• C) Allocates memory for the structure
• D) Returns a value from the function

97. How do you pass a structure to a function by reference?

• A) By using the structure variable
• B) By using a pointer to the structure
• C) By using the address of the structure
• D) Both B and C

98. Which of the following correctly defines a structure in C?

• A) struct name {int a; float b;};
• B) struct name(int a, float b);
• C) name struct {int a; float b;};
• D) struct name: {int a; float b;};

99. What is the effect of using void display(struct student o) instead of void display(struct student *o)?

• A) The original structure can be modified
• B) The original structure cannot be modified
• C) It will cause a compilation error
• D) It will cause a segmentation fault

100. Which of the following is NOT a valid way to declare a structure variable?

• A) struct student o;
• B) struct student *o;
• C) struct student o[10];
• D) student o;

101. What is the purpose of the typedef keyword in C?

• A) To create a new variable
• B) To provide existing data types with meaningful names
• C) To declare functions
• D) To allocate memory

102. How do you define a new alias for an existing data type using typedef?

• A) typedef alias_name existing_name;
• B) typedef existing_name alias_name;
• C) typedef existing_name as alias_name;
• D) alias_name typedef existing_name;

103. Which of the following correctly defines an alias for unsigned int as unit?

• A) typedef unsigned int unit;
• B) typedef unit unsigned int;
• C) unsigned int typedef unit;
• D) unsigned int unit;

104. What is the output of the following code?

                typedef struct {
                    int x;
                    int y;
                } point;
                point p = {10, 20};
                printf("%d %d", p.x, p.y);
                

• A) 10 20
• B) 0 0
• C) Compilation error
• D) 20 10

105. What does typedef struct students { ... } stu; achieve?

• A) It creates a structure called students.
• B) It creates an alias stu for the structure students.
• C) It defines a function stu.
• D) It declares a variable stu.

106. In the statement typedef int* ptr;, what does ptr represent?

• A) A function
• B) A data type
• C) A pointer to an integer
• D) An array of integers

107. How can typedef improve code readability when using structures?

• A) By shortening the code
• B) By avoiding the use of struct repeatedly
• C) By changing the data type
• D) By defining functions

108. What is the output of the following code snippet?

                    typedef int Arr[4];
                    Arr temp = {1, 2, 3, 4};
                    printf("%d", temp[2]);
                

• A) 1
• B) 2
• C) 3
• D) 4

109. Which statement is true about typedef compared to #define?

• A) typedef can define constants, while #define cannot.
• B) typedef can create new types, while #define cannot.
• C) typedef requires a semicolon at the end, while #define does not.
• D) All of the above

110. Which of the following is NOT a valid use of typedef?

• A) typedef int x;
• B) typedef int y[5];
• C) typedef struct { int a; } z;
• D) typedef #define MAX 100;

111. What is the main difference between typedef and #define?

• A) typedef is for defining constants, while #define is for data types.
• B) typedef defines data types, while #define defines constants.
• C) There is no difference; they are interchangeable.
• D) typedef requires arguments, while #define does not.

112. How would you declare a pointer to a structure using typedef?

• A) typedef struct { ... } *ptr;
• B) typedef struct { ... } ptr;
• C) typedef struct { ... } &ptr;
• D) typedef struct *ptr;

113. What is the output of the following code?

                typedef int* ptr;
                ptr p1, p2;
                int x = 10;
                p1 = &x;
                printf("%d", *p1);
                

• A) 10
• B) 0
• C) Compilation error
• D) Undefined behavior

114. When using typedef with arrays, what does it allow you to do?

• A) Create multiple array types
• B) Declare multiple variables of the same type in one line
• C) Allocate memory for arrays
• D) None of the above

115. How would you declare an array of 10 integers using typedef?

• A) typedef int arr[10];
• B) typedef int[10] arr;
• C) typedef arr int[10];
• D) int arr[10];

116. Which statement about typedef is FALSE?

• A) It can simplify complex declarations.
• B) It can create type aliases.
• C) It can be used to define constants.
• D) It can improve code readability.

117. Can you use typedef to create an alias for a function pointer?

• A) Yes
• B) No
• C) Only in C++
• D) Only for specific data types

118. What will happen if you do not include a semicolon at the end of a typedef declaration?

• A) It will compile successfully
• B) It will cause a syntax error
• C) It will be ignored
• D) It will create a default type

119. Which of the following is a valid definition of a typedef for a function that returns an integer and takes two integers as arguments?

• A) typedef int func(int, int);
• B) typedef int (*func)(int, int);
• C) typedef int func(int);
• D) typedef int func[];

120. How do you declare a variable st of type stu, where stu is defined using typedef for a structure?

• A) stu st;
• B) typedef stu st;
• C) struct st;
• D) struct stu;