Question

 Write a C program that reads in a float constant (use %f in 
   scanf) and displays its internal representation in hex. Use 
   your program to check your answers to problem 1. Hint: a union 
   is like a struct except that the fields overlap. Hint: the
   conversion code for hex is %x.

union X
{
   int a;
   float b;
};
int main()
{
 
    union X test;   
    ...

    ; test.a and test.b refer to same word in memory but have
    ; different types..

    ...

    return 0;
}

Answer 1

#include <stdio.h>

union X

{

   int a;

   float b;

};

int main(void) {

union X test;

printf("Enter a value : ");

scanf("%f",&test.b);

printf("Hex value : 0x%x",*(unsigned int*)&test.b);

               return 0;

}                            

//end of program

Output: