Passing Arguments and Returning Values

In the Introduction section, we mentioned that the caller can provide some data to the function. This is done by passing arguments to the parameters of the function.

The parameters that a function accept are part of its signature, so we need to specify them in every declaration.

The list of parameters a function can accept is contained in the parentheses after the function name. The parameters in the function parentheses are comma-separated, composed by a type, and optionally an identifier.

For example, a function taking two integer numbers would be declared as follows:

void two_ints(int, int);

If we wanted to give a name to these parameters, a and b respectively, we would write the following:

void two_ints(int a, int b);

Inside its body, the function can access the identifiers defined in the function signature as if they were declared variables. The values of the function parameters are decided when the function is called.

To call a function that takes a parameter...