C语言使用头文件实例

/* hotel.h -- constants and declarations for hotel.c */
#define QUIT       5
#define HOTEL1   180.00
#define HOTEL2   225.00
#define HOTEL3   255.00
#define HOTEL4   355.00
#define DISCOUNT   0.95
#define STARS "**********************************"

// shows list of choices
int menu(void);

// returns number of nights desired
int getnights(void);

// calculates price from rate, nights
// and displays result
void showprice(double rate, int nights);

/* hotel.c -- hotel management functions */
#include <stdio.h>
#include "hotel.h"
int menu(void)
{
    int code, status;

    printf("\n%s%s\n", STARS, STARS);
    printf("Enter the number of the desired hotel:\n");
    printf("1) Fairfield Arms           2) Hotel Olympic\n");
    printf("3) Chertworthy Plaza        4) The Stockton\n");
    printf("5) quit\n");
    printf("%s%s\n", STARS, STARS);
    while ((status = scanf("%d", &code)) != 1  ||
           (code < 1 || code > 5))
    {
        if (status != 1)
            scanf("%*s");   // dispose of non-integer input
        printf("Enter an integer from 1 to 5, please.\n");
    }

    return code;
}

int getnights(void)
{
    int nights;

    printf("How many nights are needed? ");
    while (scanf("%d", &nights) != 1)
    {
        scanf("%*s");       // dispose of non-integer input
        printf("Please enter an integer, such as 2.\n");
    }

    return nights;
}

void showprice(double rate, int nights)
{
    int n;
    double total = 0.0;
    double factor = 1.0;

    for (n = 1; n <= nights; n++, factor *= DISCOUNT)
        total += rate * factor;
    printf("The total cost will be $%0.2f.\n", total);
}