Lesson 22: Function Arguments and Return Values

Parameters and Arguments

• Parameters: Variables defined in the function definition/prototype that receive values.
• Arguments: The actual values passed to the function when it is called.

Functions with Arguments, Returning a Value

c float circle_area(float radius) { // radius is the parameter return 3.14159 * radius * radius; } // Call: float r = 4.0; float area = circle_area(r); // r is the argument

Functions with No Arguments, Returning a Value

Use void in the parameter list if no arguments are expected.

c float get_pi(void) { return 3.14159; }

Functions with Arguments, Returning void

void is used as the return type when a function performs an action but doesn't need to return a value.

c void print_message(char *msg) { printf("Message: %s\n", msg); return; // Optional return statement for void functions }

The return Statement

1. It exits the function immediately, returning control to the caller.
2. It sends a value back to the caller (if the function return type is not void).
3. The type of the returned value must match the function's declared return type (or be convertible to it).