c++ Array Parameter is producing different results

I have a function that should calculate the size of an array. However, the results is removing elements from my array.

int USERHAND[] = {8,3,4,5};

std::cout << FoundationLayer::HandSize(USERHAND);     // 1st way
std::cout << sizeof(USERHAND) / sizeof(USERHAND[0]);  // 2nd way

// Function for the 1st way
int HandSize(int* Hand) {
    return sizeof(Hand) / sizeof(Hand[0]);
}

The output for 1st way is 2 & the output for the 2nd way is 4