program for one member used at a time in union

#include <stdio.h>
#include <string.h>
union Data {
int i;
float f;
char str[20];
};
int main( ) {
union Data data;
data.i = 10;
printf( "data.i : %d\n", data.i);

data.f = 220.5;
printf( "data.f : %f\n", data.f);

strcpy( data.str, "C Programming");
printf( "data.str : %s\n", data.str);
return 0;
}

When the above code is compiled and executed, it generates the following outcome –

Here, all members are very well printed because one member is used simultaneously.