int *x = (int *)malloc(4);
*x = 20;
int *y = x;
printf("%d %d", *x, *y);
free(x);
printf("%d %p", *x, x); // x still have to value allocated using malloc
*y = 100;
// Changing the y value changes the x value even though it is unallocated
printf("%d %d", *x, *y);

20 20
20 0x7fe921d00e70
100 100