C Programming Very Tough MCQ Test (30 Questions)

Q1. What is the output of the following C code?

#include <stdio.h>
int main() {
    int a = 10;
    if (a++ > 10 && ++a > 11) {
        a++;
    }
    printf("%d", a);
    return 0;
}
  

Q2. What is the output of the following code?

#include <stdio.h>
int main() {
    int x = 5;
    printf("%d %d %d", x, x++, ++x);
    return 0;
}
  

Q3. What is the output of this recursive function?

#include <stdio.h>
int fun(int x) {
    if (x == 0) return 0;
    return x + fun(--x);
}
int main() {
    printf("%d", fun(5));
    return 0;
}
  

Q4. Which statement about pointer arithmetic is true in C?

Q5. What is the output of the following?

#include <stdio.h>
int main() {
    int a = 5;
    printf("%d", a+++++a);
    return 0;
}
  

Q6. What does the following code print?

#include <stdio.h>
int main() {
    int a = 3;
    a = a++ + ++a;
    printf("%d", a);
    return 0;
}
  

Q7. Which of the following declarations is illegal in C?

Q8. What will be the output?

#include <stdio.h>
int main() {
    char *ptr = "LiveCode";
    printf("%c", *&*&*&ptr);
    return 0;
}
  

Q9. What does the below code return?

int foo() {
    static int count = 5;
    if (--count)
        return foo();
    return count;
}
int main() {
    printf("%d", foo());
    return 0;
}
  

Q10. What is the size of the following structure?

struct test {
    char a;
    int b;
    char c;
};
  

Q11. What will the following code output?

#include <stdio.h>
int main() {
    int a = 5;
    printf("%d", a+++++a);
    return 0;
}
  

Q12. What is the output of this code?

#include <stdio.h>
int main() {
    int x = 10;
    int y = x++ + ++x;
    printf("%d", y);
    return 0;
}
  

Q13. Which C library function is unsafe due to lack of buffer boundary checks?

Q14. What will be the result of this expression: sizeof("Hello")?

Q15. What will be the output of this recursive function?

int fun(int x) {
    if (x == 1)
        return 1;
    else
        return x + fun(x - 1);
}
int main() {
    printf("%d", fun(5));
    return 0;
}
  

Q16. What will be the output of the following code?

#include <stdio.h>
int main() {
    int x = 0;
    if (x = 5)
        printf("True");
    else
        printf("False");
    return 0;
}
  

Q17. Which of the following is a correct declaration of a pointer to a function?

Q18. How many bytes are there in a pointer on a 64-bit machine?

Q19. What will be printed?

#include <stdio.h>
int main() {
    int a = 10;
    printf("%d %d", a++, ++a);
    return 0;
}
  

Q20. What will be the output?

#include <stdio.h>
#define SQUARE(x) x*x
int main() {
    int a = 5;
    int b = SQUARE(a + 1);
    printf("%d", b);
    return 0;
}
  

Q21. What is the result of this C code?

#include <stdio.h>
int main() {
    int i = 5;
    printf("%d", i+++i);
    return 0;
}
  

Q22. What does this program print?

#include <stdio.h>
int main() {
    int a = 0;
    a = a++ + ++a;
    printf("%d", a);
    return 0;
}
  

Q23. Which statement is true for const int *ptr?

Q24. What will be output?

#include <stdio.h>
int main() {
    char str[] = "abc";
    printf("%d", sizeof(str));
    return 0;
}
  

Q25. What will be the output of this code?

#include <stdio.h>
int main() {
    int a = 1;
    switch (a) {
        case 1: printf("One");
        default: printf("Default");
    }
    return 0;
}
  

Q26. What will this code output?

#include <stdio.h>
int main() {
    int x = 10;
    printf("%d", x = x++);
    return 0;
}
  

Q27. What is the result of this C expression?

int x = 4;
int y = sizeof(x++);
  

Q28. Choose the correct statement:

Q29. What is output of this recursive function?

#include <stdio.h>
int fun(int n) {
    if(n == 0) return 0;
    return n + fun(n-1);
}
int main() {
    printf("%d", fun(3));
    return 0;
}
  

Q30. Which of the following is not a storage class in C?