C Programming Questions and Answers on Typedef keyword for Freshers

1. What is the output of this C code?

1.     #include 

2.     typedef struct student

3.     {

4.         char *a;

5.     }stu;

6.     void main()

7.     {

8.         struct stu s;

9.         s.a = "hi";

10.         printf("%s", s.a);

11.     }

a) Compile time error
b) Varies
c) hi
d) h

Answer: a

2. What is the output of this C code?

1.     #include 

2.     typedef struct student

3.     {

4.         char *a;

5.     }stu;

6.     void main()

7.     {

8.         struct student s;

9.         s.a = "hey";

10.         printf("%s", s.a);

11.     }

a) Compile time error
b) Varies
c) he
d) hey

Answer: d

3. What is the output of this C code?

1.     #include 

2.     typedef int integer;

3.     int main()

4.     {

5.         int i = 10, *ptr;

6.         float f = 20;

7.         integer j = i;

8.         ptr = &j;

9.         printf("%d\n", *ptr);

10.         return 0;

11.     }

a) Compile time error
b) Undefined behaviour
c) Depends on the standard
d) 10

Answer: d

4. What is the output of this C code?

1.     #include 

2.     int (*(x()))[2];

3.     typedef int (*(*ptr)())[2] ptrfoo;

4.     int main()

5.     {

6.         ptrfoo ptr1;

7.         ptr1 = x;

8.         ptr1();

9.         return 0;

10.     }

11.     int (*(x()))[2]

12.     {

13.         int (*ary)[2] = malloc(sizeof*ary);

14.         return &ary;

15.     }

a) Compile time error
b) Nothing
c) Undefined behaviour
d) Depends on the standard

Answer: a

5. What is the output of this C code?

1.     #include 

2.     int *(*(x()))[2];

3.     typedef int **(*ptrfoo)())[2];

4.     int main()

5.     {

6.         ptrfoo ptr1;

7.         ptr1 = x;

8.         ptr1();

9.         return 0;

10.     }

11.     int *(*(x()))[2]

12.     {

13.         int (*ary)[2] = malloc(sizeof * ary);

14.         return &ary;

15.     }

a) Compile time error
b) Nothing
c) Undefined behaviour
d) Depends on the standard

Answer: b

6. What is the output of this C code?

1.     #include 

2.     typedef struct p

3.     {

4.         int x, y;

5.     };

6.     int main()

7.     {

8.         p k1 = {1, 2};

9.         printf("%d\n", k1.x);

10.     }

a) Compile time error
b) 1
c) 0
d) Depends on the standard

Answer: a

7. What is the output of this C code?

1.     #include 

2.     typedef struct p

3.     {

4.         int x, y;

5.     }k = {1, 2};

6.     int main()

7.     {

8.         p k1 = k;

9.         printf("%d\n", k1.x);

10.     }

a) Compile time error
b) 1
c) 0
d) Depends on the standard

Answer: a

8. What is the output of this C code?

1.     #include 

2.     typedef struct p

3.     {

4.         int x, y;

5.     }k;

6.     int main()

7.     {

8.         struct p p = {1, 2};

9.         k k1 = p;

10.         printf("%d\n", k1.x);

11.     }

a) Compile time error
b) 1
c) 0
d) Depends on the standard

Answer: b

9. The correct syntax to use typedef for struct is.

1. a) typedef struct temp

2.     {

3.         int a;

4.     }TEMP;

5. b) typedef struct

6.     {

7.         int a;

8.      }TEMP;

9. c) struct temp

10.     {

11.         int a;

12.     };

13.     typedef struct temp TEMP;

14. d) All of the mentioned

Answer: d

 

10. For the following expression to work, which option should be selected.
    string p = “HELLO”;

a) typedef char [] string;
b) typedef char *string;
c) typedef char [] string; and typedef char *string;
d) Such expression cannot be generated in C

Answer: b

11. Which of the given option is the correct method for initialization?
    typedef char *string;

a) *string *p = “Hello”;
b) string p = “Hello”;
c) *string p = ‘A’;
d) Not more than one space should be given when using typedef

Answer: b

12. Which of the following is FALSE about typedef?

a) typedef follow scope rules
b) typedef defined substitutes can be redefined again. (Eg: typedef char a; typedef int a;)
c) You cannot typedef a typedef with other term.
d) All of the mentioned

Answer: b

13. typedef which of the following may create problem in the program

a) ;
b) printf/scanf
c) Arithmetic operators
d) All of the mentioned

Answer: d

14. typedef int (*PFI)(char *, char *)creates

a) type PFI, for pointer to function (of two char * arguments) returning int
b) Error
c) type PFI, function (of two char * arguments) returning int
d) type PFI, for pointer

Answer: a

15. typedef declaration

a) Does not create a new type
b) It merely adds a new name for some existing type
c) Does not create a new type, It merely adds a new name for some existing type
d) None of the mentioned

Answer: c

16. What is the output of this C code?

1.     #include 

2.     typedef struct student

3.     {

4.         char *a;

5.     }stu;

6.     void main()

7.     {

8.         stu s;

9.         s.a = "hi";

10.         printf("%s", s.a);

11.     }s

a) Compile time error
b) Varies
c) hi
d) h

Answer: a