Output of C programs | Set 36

1. What will be the output of following? C

void main()
{
    int const* p = 5;
    printf("%d", ++(*p));
}

Options: A. 6 B. 5 C. Garbage Value D. Compiler Error

Answer : D

Explanation : It will give compile time error because we are trying to change the constant value. p is a pointer to a "constant integer". But we tried to change the value of the "constant integer". 2. What will be the output of following? C

void main()
{
    char* p;
    printf("%d %d", sizeof(*p), sizeof(p));
}

Options: A. 1 1 B. 1 8 C. 2 1 D. 2 2

Answer : B

Explanation : The sizeof() operator gives the number of bytes taken by its operand. P is a character pointer, which needs one byte for storing its value (a character). Hence sizeof(*p) gives a value of 1. Since it needs two bytes to store the address of the character pointer sizeof(p) gives 8. 3. What will be the output of following? C

void main()
{
    int m, i = 0, j = 1, k = 2;
    m = i++ || j++ || k++;
    printf("%d %d %d %d", m, i, j, k);
}

Options: A. 1 1 2 3 B. 1 1 2 2 C. 0 1 2 2 D. 0 1 2 3

Answer : B

Explanation : In an expression involving || operator, evaluation takes place from left to right and will be stopped if one of its components evaluates to true(a non zero value). So in the given expression m = i++ || j++ || k++. It will be stop at j and assign the current value of j in m. therefore m = 1, i = 1, j = 2 and k = 2 (since k++ will not encounter. so its value remain 2) 4. What will be the output of following? C

void main()
{
    int i = 0;
    printf("%d %d", i, i++);
}

Options: A. 0 1 B. 1 0 C. 0 0 D. 1 1

Answer : B

Explanation : Since the evaluation is from right to left. So when the print statement execute value of i = 0, as its executing from right to left - when i++ will be execute first and print value 0 (since its post increment ) and after printing 0 value of i become 1. 5. What will be the output of following? C

#include <stdio.h>
int main(void)
{
    char p;
    char buf[10] = { 1, 2, 3, 4, 5, 6, 9, 8 };
    p = (buf + 1)[5];
    printf("%d", p);
    return 0;
}

Options: A. 5 B. 6 C. 9 D. Error

Answer : C

Explanation : x[i] is equivalent to *(x + i), so (buf + 1)[5] is *(buf + 1 + 5), or buf[6].