Multiple Choice Questions and Answers for Type Conversions in C Language

List of C language interview questions on “Type Conversions” along with answers, explanations and/or solutions:

1. What is the output of this C code?

1.     #include 

2.     void main()

3.     {

4.         float x = 0.1;

5.         if (x == 0.1)

6.             printf("Sanfoundry");

7.         else

8.             printf("Advanced C Classes");

9.     }

a) Advanced C Classes
b) Sanfoundry
c) Run time error
d) Compile time error

Answer:a

2. Comment on the output of this C code?

1.     #include 

2.     void main()

3.     {

4.         float x = 0.1;

5.         printf("%d, ", x);

6.         printf("%f", x);

7.     }

a) 0.100000, junk value
b) Junk value, 0.100000
c) 0, 0.100000
d) 0, 0.999999

Answer:b

3. What is the output of this C code?

(7 and 8 are entered)

1.     #include 

2.     void main()

3.     {

4.         float x;

5.         int y;

6.         printf("enter two numbers \n", x);

7.         scanf("%f %f", &x, &y);

8.         printf("%f, %d", x, y);

9.     }

a) 7.000000, 7
b) Run time error
c) 7.000000, junk
d) Varies

Answer:c

4. What is the output of this C code?

1.     #include 

2.     void main()

3.     {

4.         double x = 123828749.66;

5.         int y = x;

6.         printf("%d\n", y);

7.         printf("%lf\n", y);

8.     }

a) 0, 0.0
b) 123828749, 123828749.66
c) 12382874, 12382874.0
d) 123828749, 0.000000

Answer:d

5. What is the output of this C code?

1.     #include 

2.     void main()

3.     {

4.         int x = 97;

5.         char y = x;

6.         printf("%c\n", y);

7.     }

a) a
b) b
c) 97
d) Run time error

Answer:a

6. When double is converted to float, the value is?

a) Truncated
b) Rounded
c) Depends on the compiler
d) Depends on the standard

Answer:c

7. What is the output of this C code?

1.     #include 

2.     int main()

3.     {

4.         unsigned int i = 23;

5.         signed char c = -23;

6.         if (i > c)

7.             printf("Yes\n");

8.         else if (i < c)

9.             printf("No\n");

10.     }

a) Yes
b) No
c) Depends on the compiler
d) Depends on the operating system

Answer:b

8. What is the output of this C code?

1.     #include 

2.     int main()

3.     {

4.         int i = 23;

5.         char c = -23;

6.         if (i < c)

7.             printf("Yes\n");

8.         else

9.             printf("No\n");

10.     }

a) Yes
b) No
c) Depends on the compiler
d) Depends on the standard

Answer:b

9. function tolower(c) defined in library works for

a) Ascii character set
b) Unicode character set
c) Ascii and utf-8 but not EBSIDIC character set
d) Any character set

Answer:d 

10. What is the output of the below code considering size of short int is 2, char is 1 and int is 4 bytes?

1.     #include 

2.     int main()

3.     {

4.         short int i = 20;

5.         char c = 97;

6.         printf("%d, %d, %d\n", sizeof(i), sizeof(c), sizeof(c + i));

7.         return 0;

8.     }

a) 2, 1, 2
b) 2, 1, 1
c) 2, 1, 4
d) 2, 2, 8

Answer:c 

11. Which type conversion is NOT accepted?

a) From char to int
b) From float to char pointer
c) From negative int to char
d) From double to char

Answer:b

Explanation:Conversion of a float to pointer type is not allowed. 

12. What will be the data type of the result of the following operation?

(float)a * (int)b / (long)c * (double)d

a) int
b) long
c) float
d) double

Answer:d 

13. Which of the following type-casting have chances for wrap around?

a) From int to float
b) From int to char
c) From char to short
d) From char to int

Answer:b 

14. Which of the following typecasting is accepted by C?

a) Widening conversions
b) Narrowing conversions
c) Both
d) None of the mentioned

Answer:c 

15. When do you need to use type-conversions?

a) The value to be stored is beyond the max limit
b) The value to be stored is in a form not supported by that data type
c) To reduce the memory in use, relevant to the value
d) All of the mentioned

Answer: d