Question

#include <stdio.h>
#include <string.h>
struct students{
    char name[50];
    int age;
    int height;
};

int main(int argc, char **argv)
{
    struct students manoj;

    strcpy(manoj.name, "manojkumar");
    manoj.age = 15;

    displaymanoj(&manoj); //print testing \n , name , age 

    return 0;
}

void displaymanoj(struct students *ptr) {
    printf("Testing...............DEBUG\n");
    printf("%s\t%d\n", ptr->name,ptr->age);
    printf("END OF TEST: SUCESS -manoj-");
}

我正在学习C，它正在使用指针指向结构变量。运行程序时，我得到了正确的输出。只是我的Geany IDE给出了一些我想知道原因的消息。

我的编译器消息如下：

Answer 1

在调用函数之前，您必须声明函数。

所以你的程序应该看起来像

// Includes
// Structure

// Function prototype declaration
// This was what you were missing before
void displaymanoj(struct students *ptr);

int main(int argc, char **argv)
{
    ...
}

void displaymanoj(struct students *ptr) {
    ...
}

Answer 2

由于从displaymanoj()调用main()时没有看到int的定义，编译器会隐式声明返回类型displaymanoj()的定义这与实际的冲突。请注意，自C99标准以来，隐式声明已被删除，并且不再有效。

修复它：

1）将函数displaymanoj()移到main（）的定义之上或
2）class Restaurant(models.Model): OPEN = 1 CLOSED = 2 OPENING_STATUS = ( (OPEN, 'open'), (CLOSED, 'closed'), ) BREAKFAST = 1 LAUNCH = 2 DINNER = 3 DELIVERY = 4 CAFE = 5 LUXURY = 6 NIGHT = 7 FEATURE_CHOICES = ( (BREAKFAST, 'breakfast'), (LAUNCH, 'launch'), (DINNER, 'dinner'), (DELIVERY, 'delivery'), (CAFE, 'cafe'), (LUXURY, 'luxury dining'), (NIGHT, 'night life'), ) MONDAY = 1 TUESDAY = 2 WEDNESDAY = 3 THURSDAY = 4 FRIDAY = 5 SATURDAY = 6 SUNDAY = 7 TIMING_CHOICES = ( (MONDAY, 'monday'), (TUESDAY, 'tuesday'), (WEDNESDAY, 'wednesday'), (THURSDAY, 'thursday'), (FRIDAY, 'friday'), (SATURDAY, 'saturday'), (SUNDAY, 'sunday'), ) user = models.ForeignKey(User) restaurant_name = models.CharField(max_length=150, db_index=True) slug = models.SlugField(max_length=150, db_index=True) address = models.CharField(max_length=100) city = models.CharField(max_length=100) restaurant_phone_number = models.PositiveIntegerField() restaurant_email = models.EmailField(blank=True, null=True) owner_email = models.EmailField(blank=True, null=True) opening_status = models.IntegerField(choices=OPENING_STATUS, default=OPEN) email = models.EmailField() restaurant_website = models.TextField(validators=[URLValidator()]) features = models.IntegerField(choices=FEATURE_CHOICES, default=DINNER) timings = models.IntegerField(choices=TIMING_CHOICES, default=MONDAY) opening_from = models.TimeField() opening_to = models.TimeField() facebook_page = models.TextField(validators=[URLValidator()]) twitter_handle = models.CharField(max_length=80, blank=True, null=True) other_details = models.TextField() available = models.BooleanField(default=True) created = models.DateTimeField(auto_now_add=True) updated = models.DateTimeField(auto_now=True) class Meta: verbose_name = 'restaurant' verbose_name_plural = 'restaurants' ordering = ('restaurant_name',) index_together = (('id','slug'),) def __str__(self): return self.restaurant_name # def get_absolute_url(self): # return reverse('restaurant:restaurant_detail', args=[self.id, self.slug]) class Category(models.Model): name = models.CharField(max_length=120,db_index=True) #veg, non-veg slug = models.SlugField(max_length=120,db_index=True) class Meta: ordering=('name', ) verbose_name = 'category' verbose_name_plural = 'categories' def __str__(self): return self.name class Menu(models.Model): category = models.ForeignKey(Category, related_name="menu") restaurant = models.ForeignKey(Restaurant, related_name="restaurant_menu") name = models.CharField(max_length=120,db_index=True) slug = models.SlugField(max_length=120,db_index=True) image = models.ImageField(upload_to='products/%Y/%m/%d', blank=True) description = models.TextField(blank=True) price = models.DecimalField(max_digits=10,decimal_places=2) stock = models.PositiveIntegerField() available = models.BooleanField(default=True) created = models.DateTimeField(auto_now_add=True) updated = models.DateTimeField(auto_now=True) class Meta: ordering=('name', ) index_together = (('id', 'slug'), ) verbose_name = 'menu' def __str__(self): return self.name # def get_absolute_url(self): # return reverse('restaurant:menu_detail', args=[self.id, self.slug]) from django.db import models from restaurant.models import Menu class Order(models.Model): first_name = models.CharField(max_length=50) last_name = models.CharField(max_length=50) email = models.EmailField() address = models.CharField(max_length=250) postal_code = models.CharField(max_length=20) city = models.CharField(max_length=50) created = models.DateTimeField(auto_now_add=True) updated = models.DateTimeField(auto_now=True) paid = models.BooleanField(default=False) class Meta: ordering = ('-created',) def __str__(self): return 'Order {}'.format(self.id) def get_total_cost(self): return sum(item.get_cost() for item in self.items.all()) class OrderItem(models.Model): order = models.ForeignKey(Order, related_name='items') product = models.ForeignKey(Product, related_name='order_items') price = models.DecimalField(max_digits=10, decimal_places=2) quantity = models.PositiveIntegerField(default=1) def __str__(self): return '{}'.format(self.id) def get_cost(self): return self.price * self.quantity。{/ p>

53：6：警告：功能冲突的类型

2 个答案: