Ampersand question

[whatusername]

I'm trying to understand what the ampersand mean when it comes to function arguments/parameters.

What does the (int &a, int b) in functiontwo mean? Thanks.

int functiontwo (int &a, int b)
{
     int z = a + b;
     b = a + z;
     a +=  z + b;
     cout << "a = " << a << "b = " << b << "c = " << c << "\n";
     return a + b + z;
}
int main()
{
     int a = 2, b = 3, c;
     c = functiontwo(b, a);
     cout << "a = " << a << "b = " << b << "c = " << c << endl;
     b = functiontwo(a, c);
     cout << "a = " << a << "b = " << b << "c = " << c << endl;
     return 0;
}

[TarikNeaj]

It your case, it's called a reference. Call by reference more specifically.

http://www.tutorialspoint.com/cplusplus/cpp_function_call_by_reference.htm

[whatusername]

Thank you.