### Examples of Function Declarations

The following example defines the function `absolute` with the return type double. Because this is a non-integer return type, `absolute` is declared prior to the function call.

>     #include <stdio.h>

>     double absolute(double);

>     int main(void)
>     {
>        double f = -3.0;

>        printf("absolute number = %lf\n", absolute(f));
>     }

>     double absolute(double number)
>     {
>        if (number < 0.0)
>           number = -number;

>        return number;
>     }

The following example defines the function `absolute` with the return type void. Within the function `main`, `absolute` is declared with the return type void.

>     #include <stdio.h>

>     int main(void)
>     {
>        void absolute(float);
>        float f = -8.7;

>        absolute(f);
>     }

>     void absolute(float number)
>     {
>        if (number < 0.0)
>           number = -number;

>        printf("absolute number = %f\n", number);
>     }

Functions
Function Calls

main() Function
Function Declarations
Function Definitions
Examples of Function Calls
Example of the main() Function
Examples of Function Definitions