Structure and Union MCQs

What will be the output of the following C code?

#include <stdio.h>
int main()
{
    typedef struct p *q;
    struct p
    {
        int x;
        char y;
        q ptr;
    };
    struct p p = {1, 2, &p};
    printf("%d\n", p.ptr->x);
    return 0;
}

Can the following C code be compiled successfully?

#include <stdio.h>
struct p
{
    int k;
    char c;
    float f;
};
int main()
{
    struct p x = {.c = 97, .f = 3, .k = 1};
    printf("%f\n", x.f);
}

What will be the output of the following C code?

#include <stdio.h>
int *(*(x()))[2];
typedef int **(*ptrfoo)())[2];
int main()
{
    ptrfoo ptr1;
    ptr1 = x;
    ptr1();
    return 0;
}
int *(*(x()))[2]
{
    int (*ary)[2] = malloc(sizeof * ary);
    return &ary
}

Which of the following share a similarity in syntax?

1. Union, 2. Structure, 3. Arrays and 4. Pointers

What will be the output of the following C code?

#include <stdio.h>
void main()
{
    struct student
    {
        int no;
        char name[20];
    };
    struct student s;
    no = 8;
    printf("%d", no);
}

What will be the output of the following C code?

#include <stdio.h>
struct p
{
    int x;
    char y;
};
int main()
{
    struct p p1[] = {1, 92, 3, 94, 5, 96};
    struct p *ptr1 = p1;
    int x = (sizeof(p1) / sizeof(struct p));
    printf("%d %d\n", ptr1->x, (ptr1 + x - 1)->x);
}

What will be the output of the following C code?

#include <stdio.h>
struct point
{
    int x;
    int y;
};
int main()
{
    struct point p = {1};
    struct point p1 = {1};
    if(p == p1)
        printf("equal\n");
    else
        printf("not equal\n");
}

Which of the following structure declaration doesn't require pass-by-reference?

struct{int a;}s;
main(){}

struct temp{int a;};
main(){
    struct temp s;
}

struct temp{int a;};
main(){}
struct temp s;

How many bytes in memory taken by the following C structure?

#include <stdio.h>
struct test
{
    int k;
    char c;
};