Multiple Choice Questions and Answers for Precedence and Order of Evaluation in C Language

List of C language interview questions “Precedence and Order of Evaluation” along with answers, explanations and/or solutions:

1. What is the output of this C code?

1.     #include 

2.     int main()

3.     {

4.         reverse(1);

5.     }

6.     void reverse(int i)

7.     {

8.         if (i > 5)

9.             exit(0);

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

11.         return reverse(i++);

12.     }

a) 1 2 3 4 5
b) 1 2 3 4
c) Compile time error
d) Stack overflow

Answer:d

2. What is the output of this C code?

1.     #include 

2.     void reverse(int i);

3.     int main()

4.     {

5.         reverse(1);

6.     }

7.     void reverse(int i)

8.     {

9.         if (i > 5)

10.             return ;

11.         printf("%d ", i);

12.         return reverse((i++, i));

13.     }

a) 1 2 3 4 5
b) Segmentation fault
c) Compilation error
d) Undefined behaviour

Answer:a

3. In expression i = g() + f(), first function called depends on

a) Compiler
b) Associativiy of () operator
c) Precedence of () and + operator
d) Left to write of the expression

Answer:a 

4. What is the value of i and j in the below code?

1.     #include 

2.     int x = 0;

3.     int main()

4.     {

5.         int i = (f() + g()) || g();

6.         int j = g() || (f() + g());

7.     }

8.     int f()

9.     {

10.         if (x == 0)

11.             return x + 1;

12.         else

13.             return x - 1;

14.     }

15.     int g()

16.     {

17.         return x++;

18.     }

a)i value is 1 and j value is 1
b)i value is 0 and j value is 0
c)i value is 1 and j value is undefined
d)i and j value are undefined

Answer:d

5. What is the value of i and j in the below code?

1.     #include 

2.     int x = 0;

3.     int main()

4.     {

5.         int i = (f() + g()) | g(); //bitwise or

6.         int j = g() | (f() + g()); //bitwise or

7.     }

8.     int f()

9.     {

10.         if (x == 0)

11.             return x + 1;

12.         else

13.             return x - 1;

14.     }

15.     int g()

16.     {

17.         return x++;

18.     }

a) i value is 1 and j value is 1
b) i value is 0 and j value is 0
c) i value is 1 and j value is undefined
d) i and j value are undefined

Answer:c

6. What is the output of this C code?

1.     #include 

2.     int main()

3.     {

4.         int x = 2, y = 0;

5.         int z = y && (y |= 10);

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

7.         return 0;

8.     }

a) 1
b) 0
c) Undefined behaviour due to order of evaluation
d) 2

Answer:b

7. What is the output of this C code?

1.     #include 

2.     int main()

3.     {

4.         int x = 2, y = 0;

5.         int z = (y++) ? 2 : y == 1 && x;

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

7.         return 0;

8.     }

a) 0
b) 1
c) 2
d)Undefined behaviour

Answer:b

8. What is the output of this C code?

1.     #include 

2.     int main()

3.     {

4.         int x = 2, y = 0;

5.         int z;

6.         z = (y++, y);

7.         printf("%d\n", z);

8.         return 0;

9.     }

a) 0
b) 1
c) Undefined behaviour
d) Compilation error

Answer:b

9. What is the output of this C code?

1.     #include 

2.     int main()

3.     {

4.         int x = 2, y = 0, l;

5.         int z;

6.         z = y = 1, l = x && y;

7.         printf("%d\n", l);

8.         return 0;

9.     }

a) 0
b) 1
c) Undefined behaviour due to order of evaluation can be different
d) Compilation error

Answer:b

10. What is the output of this C code?

1.     #include 

2.     int main()

3.     {

4.         int y = 2;

5.         int z = y +(y = 10);

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

7.     }

a) 12
b) 20
c) 4
d) Either 12 or 20

Answer:b

11. What is the output of this C code?

1.     #include 

2.     void main()

3.     {

4.         int b = 5 - 4 + 2 * 5;

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

6.     }

a) 25
b) -5
c) 11
d) None of the mentioned

Answer:c 

12. What is the output of this C code?

1.     #include 

2.     void main()

3.     {

4.         int b = 5 & 4 & 6;

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

6.     }

a) 5
b) 6
c) 3
d) 4

Answer:d 

13. What is the output of this C code?

1.     #include 

2.     void main()

3.     {

4.         int b = 5 & 4 | 6;

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

6.     }

a) 6
b) 4
c) 1
d) 0

Answer:a 

14. What is the output of this C code?

1.     #include 

2.     void main()

3.     {

4.         int b = 5 + 7 * 4 - 9 * (3, 2);

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

6.     }

a) 6
b) 15
c) 13
d) 21

Answer:b 

15. What is the output of this C code?

1.     #include 

2.     void main()

3.     {

4.         int h = 8;

5.         int b = (h++, h++);

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

7.     }

a) 10 10
b) 10 9
c) 9 10
d) 8 10

Answer:c 

16. What is the output of this C code?

1.     #include 

2.     void main()

3.     {

4.         int h = 8;

5.         int b = h++ + h++ + h++;

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

7.     }

a) 9
b) 10
c) 12
d) 11

Answer:d 

17. What is the output of this C code?

1.     #include 

2.     void main()

3.     {

4.         int h = 8;

5.         int b = 4 * 6 + 3 * 4 < 3 ? 4 : 3;

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

7.     }

a) 3
b) 33
c) 34
d) Run time error

Answer:a 

18. What is the output of this C code?

1.     #include 

2.     void main()

3.     {

4.         int a = 2 + 3 - 4 + 8 -  5 % 4;

5.         printf("%d\n", a);

6.     }

a) 0
b) 8
c) 11
d) 9

Answer:b 

19. What is the output of this C code?

1.     #include 

2.     void main()

3.     {

4.         char a = '0';

5.         char b = 'm';

6.         int c = a && b || '1';

7.         printf("%d\n", c);

8.     }

a) 0
b) a
c) 1
d) m

Answer:c 

20. What is the output of this C code?

1.     #include 

2.     void main()

3.     {

4.         char a = 'A';

5.         char b = 'B';

6.         int c = a + b % 3 - 3 * 2;

7.         printf("%d\n", c);

8.     }

a) 65
b) 58
c) 64
d) 59

Answer:d