What does this program do and would you improve it?

//Ex. 7.18: Ex07_18.cpp
 //What does this program do?
 #include <iostream>
 using std::cout;
 using std::endl;

 int whatIsThis ( int [], int); //function protoype

 int main()

 {
 const int arraySize = 10;
 int a [arraySize] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10};

 int result = whatIsThis (a,arraySize);

 cout << "Results is " <<result << endl;
 return 0; //indicates successful termination
 } // end main

 //What does this function do?
 int whatIsThis ( int b[], int size)
 {
 if (size == 1) // base case
 return b [0];
 else // recursive step
 return b [size-1]+ whatIsThis (b, size - 1);
 } // end function whatIsThis