* x = a； * y = b；

Pointer variables x, y are not initialized, and uncertain values (junk values) are stored in variables. Indirect access to uncertain memory locations is illegal. So "* x = a；; * y = b； "Illegal." * x = & ampa； * y = & ampb； "Similarly, whether the types on both sides of the assignment number" = "are compatible or not is ignored here for the time being.

int a=3，b=4，*x，* y；

x = & ampa； y = & ampb； //& amp； A, A & ampB take the addresses of variables A and B respectively, and then assign values to pointer variables X and Y. ..

At this time, X points to A (the address where X stores A), Y points to B, and A can be accessed through *x (*x and A are equivalent). In this case, * x and A both represent the same storage location. So what you wrote in the end is correct. Remember, before accessing the pointer indirectly, make sure that the pointer points to a clear memory location.