C++ Primer, Fifth Edition

Calling a Function

To call fact, we must supply an int value. The result of the call is also an int:

int main(){    int j = fact(5);  // j equals 120, i.e., the result of fact(5)    cout << "5! is " << j << endl;    return 0;}

A function call does two things: It initializes the function’s parameters from the corresponding arguments, and it transfers control to that function. Execution of the calling function is suspended and execution of the called function begins.

Execution of a function begins with the (implicit) definition and initialization of its parameters. Thus, when we call fact, the first thing that happens is that an int variable named val is created. This variable is initialized by the argument in the call to fact, which in this case ...