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

Here is the completed code for this problem. Comments are included, go through it, learn how things work and let me know if you have any doubts or if you need anything to change. If you are satisfied with the solution, please rate the answer. Thanks

#include<stdio.h>

union X

{

   int a;

   float b;

};

int main()

{

    union X test;

                printf("Enter a float value: ");

                //reading a float value to test.b

                scanf("%f",&test.b);

                //since test.a and test.b refer to the same word in memory, we can print out

                //test.a as hex using %x format specifier to print out the hex equivalent of

                //the input value.

                printf("Hex value: %x\n",test.a);

    return 0;

}

/*OUTPUT*/

Enter a float value: 3.14

Hex value: 4048f5c3