C Programming – Pointer to Structures

C Programming - Pointer to Structures

Question 1

What is the output of this C code?

    #include 
    struct p
    {
    int x;
    char y;
    };
    int main()
    {
    struct p p1[] = {1, 92, 3, 94, 5, 96};
    struct p *ptr1 = p1;
    int x = (sizeof(p1) / 3);
    if (x == sizeof(int) + sizeof(char))
    printf("%d\n", ptr1->x);
    else
    printf("falsen");
    }

A	Compile time error
B	1
C	Undefined behaviour
D	false

Question 2

What is the output of this C code?

    #include 
    struct p
    {
    int x;
    char y;
    };
    int main()
    {
    struct p p1[] = {1, 92, 3, 94, 5, 96};
    struct p *ptr1 = p1;
    int x = (sizeof(p1) / sizeof(ptr1));
    if (x == 1)
    printf("%d\n", ptr1->x);
    else
    printf("false\n");
    }

A	Compile time error
B	1
C	false
D	Undefined behaviour

Question 3

What is the output of this C code?

    #include 
    struct p
    {
    int x;
    char y;
    };
    typedef struct p* q*;
    int main()
    {
    struct p p1[] = {1, 92, 3, 94, 5, 96};
    q ptr1 = p1;
    printf("%d\n", ptr1->x);
    }

A	Compile time error
B	1
C	Undefined behaviour
D	Segmentation fault

Question 4

What is the output of this C code?

    #include 
    struct p
    {
    int x;
    char y;
    };
    void foo(struct p* );
    int main()
    {
    typedef struct p* q;
    struct p p1[] = {1, 92, 3, 94, 5, 96};
    foo(p1);
    }
    void foo(struct p* p1)
    {
    q ptr1 = p1;
    printf("%d\n", ptr1->x);
    }

A	Compile time error
B	1
C	Segmentation fault
D	Undefined behaviour

Question 5

Which of the following are incorrect syntax for pointer to structure?    (Assuming struct temp{int b;}*my_struct;)

A	*my_struct.b = 10;
B	(*my_struct).b = 10;
C	my_struct->b = 10;
D	Both (a) and (b)

Question 6

Which of the following is an incorrect syntax to pass by reference a member of a structure in      a function?     (Assume: struct temp{int a;}s;)

A	func(&s.a);
B	func(&(s).a);
C	func(&(s.a));
D	None of the mentioned

Question 7

Which of the following structure declaration doesn’t require pass-by-reference?

A	struct{int a;}s; main(){}
B	struct temp{int a;}; main(){ struct temp s; }
C	struct temp{int a;}; main(){} struct temp s;
D	None of the mentioned

Question 8

 For the following function call which option is not possible?     func(&s.a); //where s is a variable of type struct and a is the member of the struct.

A	Compiler can access entire structure from the function.
B	Individual member’s address can be displayed in structure.
C	Individual member can be passed by reference in a function.
D	Both (b) and (c).

Question 9

Comment on the output of this C code?

    #include 
    struct temp
    {
    int a;
    } s;
    void change(struct temp);
    main()
    {
    s.a = 10;
    change(s);
    printf("%d\n", s.a);
    }
    void change(struct temp s)
    {
    s.a = 1;
    }

A	Output will be 1
B	Output will be 10
C	Output varies with machine
D	Compile time error

Question 10

What is the output of this C code?

    #include 
    struct p
    {
    int x;
    int y;
    };
    int main()
    {
    struct p p1[] = {1, 92, 3, 94, 5, 96};
    struct p *ptr1 = p1;
    int x = (sizeof(p1) / 5);
    if (x == 3)
    printf("%d %d\n", ptr1->x, (ptr1 + x - 1)->x);
    else
    printf("false\n");
    }

A	Compile time error
B	1 5
C	Undefined behaviour
D	false

Question 11

What is the output of this C code?

    #include 
    struct student
    {
    char *c;
    };
    void main()
    {
    struct student m;
    struct student *s = &m;
    s->c = "hello";
    printf("%s", s->c);
    }

A	hello
B	Run time error
C	Nothing
D	Depends on compiler

Question 12

What is the output of this C code?

    #include 
    struct student
    {
    char *c;
    };
    void main()
    {
    struct student *s;
    s->c = "hello";
    printf("%s", s->c);
    }

A	hello
B	Segmentation fault
C	Run time error
D	Nothing

Question 13

What is the output of this C code?

    #include 
    struct student
    {
    char *c;
    };
    void main()
    {
    struct student m;
    struct student *s = &m;
    s->c = "hello";
    printf("%s", m.c);
    } 

A	Run time error
B	Nothing
C	hello
D	Varies

Question 14

What is the output of this C code?

    #include 
    struct student
    {
    char *c;
    };
    void main()
    {
    struct student m;
    struct student *s = &m;
    (*s).c = "hello";
    printf("%s", m.c);
    }

A	Run time error
B	Nothing
C	Varies
D	hello

Question 15

What is the output of this C code?

    #include 
    struct student
    {
    char *c;
    };
    void main()
    {
    struct student n;
    struct student *s = &n;
    (*s).c = "hello";
    printf("%p\n%p\n", s, &n);
    }

A	Different address
B	Run time error
C	Nothing
D	Same address

Question 16

What is the output of this C code?

    #include 
    struct p
    {
    int x[2];
    };
    struct q
    {
    int *x;
    };
    int main()
    {
    struct p p1 = {1, 2};
    struct q *ptr1;
    ptr1->x = (struct q*)&p1.x;
    printf("%d\n", ptr1->x[1]);
    }

A	Compile time error
B	Segmentation fault/code crash
C	2
D	1

Question 17

What is the output of this C code?

    #include 
    struct p
    {
    int x[2];
    };
    struct q
    {
    int *x;
    };
    int main()
    {
    struct p p1 = {1, 2};
    struct q *ptr1 = (struct q*)&p1;
    ptr1->x = (struct q*)&p1.x;
    printf("%d\n", ptr1->x[0]);
    }

A	Compile time error
B	Undefined behaviour
C	Segmentation fault/code crash
D	1

Question 18

What is the output of this C code?

    #include 
    struct p
    {
    int x;
    int y;
    };
    int main()
    {
    struct p p1[] = {1, 2, 3, 4, 5, 6};
    struct p *ptr1 = p1;
    printf("%d %d\n", ptr1->x, (ptr1 + 2)->x);
    }

A	1 5
B	1 3
C	Compile time error
D	1 4

Question 19

What is the output of this C code?

    #include 
    struct p
    {
    int x;
    char y;
    };
    int main(){
    struct p p1[] = {1, 92, 3, 94, 5, 96};
    struct p *ptr1 = p1;
    int x = (sizeof(p1) / sizeof(struct p));
    printf("%d %d\n", ptr1->x, (ptr1 + x - 1)->x);
    }

A	Compile time error
B	Undefined behaviour
C	1 3
D	1 5

Check Your Answers:

  1. D

  2. C

  3. A

  4. A

  5. A

  6. D

  7. D

  8. A

  9. B

10. D

11. A

12. B

13. C

14. D

15. D

16. B

17. B

18. A

19. D

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