The following is the example program to explain "using bit fields inside an union". #include<stdio.h> union Point { unsigned int x:4; unsigned int y:4; int res; }; int main() { union Point pt; pt.x = 2; pt.y = 3; pt.res = pt.y; printf("\n The value of res = %d" , pt.res); return 0; } // Output: The value of res = 3