Return array in a function

Question

I have an array int arr[5] that is passed to a function fillarr(int arr[]):

int fillarr(int arr[])
{
    for(...);
    return arr;
         


        

Answer 1

In this case, your array variable arr can actually also be treated as a pointer to the beginning of your array's block in memory, by an implicit conversion. This syntax that you're using:

int fillarr(int arr[])

Is kind of just syntactic sugar. You could really replace it with this and it would still work:

int fillarr(int* arr)

So in the same sense, what you want to return from your function is actually a pointer to the first element in the array:

int* fillarr(int arr[])

And you'll still be able to use it just like you would a normal array:

int main()
{
  int y[10];
  int *a = fillarr(y);
  cout << a[0] << endl;
}