C Programming Questions and Answers on Precedence and Order of Evaluation for Freshers

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.     int main()

3.     {

4.         int x = 2, y = 2;

5.         float f = y + x /= x / y;

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

7.         return 0;

8.     }

a) 2 4.000000
b) Compile time error
c) 2 3.500000
d) Undefined behaviour

Answer: b

12. What is the output of this C code?

1.     #include 

2.     int main()

3.     {

4.         int x = 1, y = 2;

5.         if (x && y == 1)

6.             printf("true\n");

7.         else

8.             printf("false\n");

9.     }

a) true
b) false
c) compile time error
d) undefined behaviour

Answer: b

13. What is the output of this C code?

1.     #include 

2.     int main()

3.     {

4.         int x = 1, y = 2;

5.         int z = x & y == 2;

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

7.     }

a) 0
b) 1
c) Compile time error
d) Undefined behaviour

Answer: b

14. What is the output of this C code?

1.     #include 

2.     int main()

3.     {

4.         int x = 3, y = 2;

5.         int z = x /= y %= 2;

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

7.     }

a) 1
b) Compile time error
c) Floating point exception
d) Segmentation fault

Answer: c

15. What is the output of this C code?

1.     #include 

2.     int main()

3.     {

4.         int x = 3, y = 2;

5.         int z = x << 1 > 5;

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

7.     }

a) 1
b) 0
c) 3
d) Compile time error

Answer: a

16. What is the output of this C code?

1.     #include 

2.     int main()

3.     {

4.         int x = 3; //, y = 2;

5.         const int *p = &x;

6.         *p++;

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

8.     }

a) Increment of read-only location compile error
b) 4
c) Some garbage value
d) Undefined behaviour

Answer: c

17. What is the output of this C code?

1.     #include 

2.     int main()

3.     {

4.         int x = 2, y = 2;

5.         int z = x ^ y & 1;

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

7.     }

a) 1
b) 2
c) 0
d) 1 or 2

Answer: b

18. What is the output of this C code?

1.     #include 

2.     int main()

3.     {

4.         int x = 2, y = 0;

5.         int z = x && y = 1;

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

7.     }

a) 0
b) 1
c) Compile time error
d) 2

Answer: c
.

19. What is the output of the code given below

1.     #include 

2.     int main()

3.     {

4.         int x = 0, y = 2;

5.         if (!x && y)

6.             printf("true\n");

7.         else

8.             printf("false\n");

9.     }

a) true
b) false
c) compile time error
d) undefined behaviour

Answer: a

20. What is the output of this C code?

1.     #include 

2.     int main()

3.     {

4.         int x = 0, y = 2;

5.         int z = ~x & y;

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

7.     }

a) -1
b) 2
c) 0
d) Compile time error

Answer: b

21. What is the output of this C code?

1.     #include 

2.     void main()

3.     {

4.         int a = 5 * 3 + 2 - 4;

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

6.     }

a) 13
b) 14
c) 12
d) 1 6

Answer: a

22. What is the output of this C code?

1.     #include 

2.     void main()

3.     {

4.         int a = 2 + 4 + 3 * 5 / 3 - 5;

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

6.     }

a) 7
b) 6
c) 10
d) 9

Answer: b

23. What is the output of this C code?

1.     #include 

2.     void main()

3.     {

4.         int a = 5 * 3 % 6 - 8 + 3;

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

6.     }

a) 10
b) 2
c) -2
d) -3

Answer: c

24. What is the output of this C code?

1.     #include 

2.     void main()

3.     {

4.         int b = 6;

5.         int c = 7;

6.         int a = ++b + c--;

7.         printf("%d", a);

8.     }

a) Run time error
b) 15
c) 13
d) 14

Answer: d

25. What is the output of this C code?

1.     #include 

2.     void main(

3.     {

4.         double b = 8;

5.         b++;

6.         printf("%lf", b);

7.     }

a) 9.000000
b) 9
c) 9.0
d) Run time error

Answer: a

26. What is the output of this C code?

1.     #include 

2.     void main()

3.     {

4.         double b = 3 % 0 * 1 - 4 / 2;

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

6.     }

a) -2
b) Floating point Exception
c) 1
d) None of the mentioned

Answer: b

27. What is the output of this C code?

1.     #include 

2.     void main()

3.     {

4.         double b = 5 % 3 & 4 + 5 * 6;

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

6.     }

a) 2
b) 30
c) 2.000000
d) Run time error

Answer: c

28. What is the output of this C code?

1.     #include 

2.     void main()

3.     {

4.         double b = 3 && 5 & 4 % 3;

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

6.     }

a) 3.000000
b) 4.000000
c) 5.000000
d) 1.000000

Answer: d
.

29. What is the output of this C code?

1.     #include 

2.     void main()

3.     {

4.         double b = 5 & 3 && 4 || 5 | 6;

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

6.     }

a) 1.000000
b) 0.000000
c) 7.000000
d) 2.000000

Answer: a

30. What is the output of this C code?

1.     #include 

2.     void main()

3.     {

4.         int k = 0;

5.         double b = k++ + ++k + k--;

6.         printf("%d", k);

7.     }

a) 6
b) 1
c) 5
d) undefined

Answer: d