Union in C Language - Quiz

What is the output of this C code? 

    #include <stdio.h>
    union p
    {
        int x;
        float y;
    };
    int main()
    {
        union p p, b;
        p.x = 10;
        printf("%f\n", p.y);
    }

  • A Compile time error
  • B Implementation dependent
  • C 10.000000
  • D 0.000000

What will be the output of the program in Turbo C (under DOS)? 

#include<stdio.h>

int main()
{
    struct emp
    {
        char *n;
        int age;
    };
    struct emp e1 = {"Dravid", 23};
    struct emp e2 = e1;
    strupr(e2.n);
    printf("%s\n", e1.n);
    return 0;
}

  • A Error: Invalid structure assignment
  • B DRAVID
  • C Dravid
  • D No output

What is the output of this C code? 

    #include <stdio.h>
    union p
    {
        int x;
        char y;
    };
    int main()
    {
        union p p, b;
        p.y = 60;
        b.x = 12;
        printf("%d\n", p.y);
    }

  • A Compile time error
  • B Depends on the compiler
  • C 60
  • D Undefined behaviour

What type of data is holded by variable u int this C code? 

    #include <stdio.h>
    union u_tag
    {
        int ival;
        float fval;
        char *sval;
    } u;
The variable u here
  • A Will be large enough to hold the largest of the three types;
  • B Will be large enough to hold the smallest of the three types;
  • C Will be large enough to hold the all of the three types;
  • D None of the mentioned

What will be the output of the program? 

#include<stdio.h>

int main()
{
    enum days {MON=-1, TUE, WED=6, THU, FRI, SAT};
    printf("%d, %d, %d, %d, %d, %d\n", ++MON, TUE, WED, THU, FRI, SAT);
    return 0;
}

  • A -1, 0, 1, 2, 3, 4
  • B Error
  • C 0, 1, 6, 3, 4, 5
  • D 0, 0, 6, 7, 8, 9

What is the output of this C code? 

    #include <stdio.h>
    union
    {
        int x;
        char y;
    }p;
    int main()
    {
        p.y = 60;
        printf("%d\n", sizeof(p));
    }

  • A Compile time error
  • B sizeof(int) + sizeof(char)
  • C Depends on the compiler
  • D sizeof(char)

What will be the output of the program? 
#include"stdio.h"

int main()
{
    union var
    {
        int a, b;
    };
    union var v;
    v.a=10;
    v.b=20;
    printf("%d\n", v.a);
    return 0;
}

  • A 10
  • B 20
  • C 30
  • D 0

What will be the output of the program in 16-bit platform (under DOS)? 

#include<stdio.h>

int main()
{
    struct node
    {
        int data;
        struct node *link;
    };
    struct node *p, *q;
    p = (struct node *) malloc(sizeof(struct node));
    q = (struct node *) malloc(sizeof(struct node));
    printf("%d, %d\n", sizeof(p), sizeof(q));
    return 0;
}

  • A 2, 2
  • B 8, 8
  • C 5, 5
  • D 4, 4

Members of a union are accessed as________________
  • A union-name.member
  • B union-pointer->member
  • C both union-name.member & union-pointer->member
  • D none of the mentioned