C Union Enum Bitfields Macros 31May2023

What is the size of union u? (runs in GDB compiler)

union u{

int x;

float y;

char z[10];

};

• 10

• 8

• 12

• 18

#include <stdio.h>

union u {

int x;

float y;

char z[10];

};

int main()

{

u.x = 2;

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

return 0;

}

• 2

• compile time error

• undefined output

• run time error

#include <stdio.h>

union u{

int x;

float y;

char z[10];

};

int main()

{

union u uu;

uu.x = 2;

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

return 0;

}

#include <stdio.h>

union u{

int x;

float y;

char z[10];

};

int main()

{

union u uu;

uu.x = 65;

printf("%c\n",uu.z[0]);

return 0;

}

• 65

• A

• AA

• Undefined

#include <stdio.h>

struct s {

int x:5;

float y:6

};

int main()

{

struct s ss;

return 0;

}

• Compile time error

• Run time error

• No output

struct s{

int x:5;

float y;

};

When sizeof(struct s) is used, ________ bytes is allocated;

struct s{

int x:5;

};

When sizeof(struct s) is used, ________ bytes is allocated;

#include <stdio.h>

struct s{

int x:5;

char y;

};

int main()

{

struct s ss;

printf("%ld\n", sizeof(struct s));

return 0;

}

• 4 bytes

• 13 bits

• 2 bytes

• 8 bytes

#include <stdio.h>

enum vehicle {Auto, Bus=3, Car, Van};

int main()

{

enum vehicle v;

v = Van;

printf("%d",v);

return 0;

}

Identify from the list which is NOT a C macro?

• #define

• #time

• #else

• #ifdef