Is there a difference between a pointer parameter and an array parameter?

Question

void method(double *v)

void method(double v[5])

Is there any difference between these two?

Is the second one more specific,

Answer 1

Arrays when declared as parameter types, decay to the pointer types. In your example,

void method(double v[5]);

Here 5 doesn't play any role at all, it is so insignificant that you may omit it altogether, and write this instead:

void method(double v[]);

which is exactly same as the previous declaration. Since it decays into pointer, so the above two are exactly same as:

void method(double *v); //because array decays to pointer, anyway

That is, all the following are declarations of the same function:

void method(double v[5]); //ok : declaration 
void method(double v[]);  //ok : redeclaration of the above
void method(double *v);   //ok : redeclaration of the above

ALL are exactly same. No difference at all.

Note that the following is different however:

void f(double (&v)[5]); 

It declares a function which can take array of doubles of size exactly 5. If you pass array of any other size (or if you pass pointers), it will give compilation error!