Use pointer or array in function parameters [duplicate]

Question

is 1) float scalar_product(float *x, float *y) the same as 2) float scalar_product(float x[], float y[])?

I got some float a[3], b[3]; which contains some vectors and the function should give me the scalar product.

With my java background I wrote the 2) function (on paper) but the sample solution used the 1) with pointer's.

So my questions: Are they the same? If not, whats the difference and when should I use which?

Answer 1

Yes, both the versions are effectively same, because, when arrays are passed as function arguments, they essentially decay to the pointer to the first element.

So, making the function parameter as pointer or array will have no behavioral change.

Related, C11, chapter §6.7.6.3, Function declarators

A declaration of a parameter as ‘‘array of type’’ shall be adjusted to ‘‘qualified pointer to type’’ [...]

So, float scalar_product(float x[], float y[]) ends up being the same as float scalar_product(float *x, float *y).