如何解决 "parameter has incomplete type" 错误？

Question

我是新手，我需要帮助来调试我的代码。当我编译它时 'type of formal parameter 1 is incomplete' and type of formal parameter 2 is incomplete' 错误出现在

 printf("Age is %d years.\n", calc_age(birth, current));

while 'parameter 1 ('birth') has incomplete type' and 'parameter 2 ('current') has incomplete type'错误出现在

int calc_age (struct date birth, struct date current) {

感谢帮助，谢谢！

#include <stdio.h>
int calc_age (struct date birth, struct date current);


int main(void)
{

    struct date {
        int month[1];
        int day[1];
        int year[1];

};


    struct date birth, current;
    char c;

    printf("Input the birthdate (MM/DD/YY): ");
    scanf("%d %c %d %c %d", birth.month, &c, birth.day, &c, birth.year);
    printf("Input date to calculate (MM/DD/YY): ");
    scanf("%d %c %d %c %d", current.month, &c,  current.day, &c, current.year);

    printf("Age is %d years.\n", calc_age(birth, current));

    return 0;

}

int calc_age (struct date birth, struct date current) {

    int age;

    if (birth.month[0] < current.month[0]) {
        age = (current.year[0] - birth.year[0]);
    } else if (birth.month[0] > current.month[0]) {
        age = (current.year[0] - birth.year[0] - 1);
    } else {
        if (birth.day[0] <= current.day[0]) {
            age = (current.year[0] - birth.year[0]);
        } else {
            age = (current.year[0] - birth.year[0] - 1);
        }
    }

    return age;
}

Answer 1

您的程序显示 incomplete type 错误，因为 struct date 的范围仅限于 main() 函数。在 main() 之外，结构定义不可见。

因此，struct date 定义应该在全局范围内，以便它在 calc_age() 中可见（也许还有其他函数）。更好的是，如果您可以为此目的创建和维护一个头文件。

也就是说，在您的代码中，根据您当前的要求，去掉结构中的单元素数组，例如

struct date {
    int month;
    int day;
    int year;
 };

还有 scanf() 声明

scanf("%d %c %d %c %d", birth.month, &c, birth.day, &c, birth.year);

应该阅读

scanf("%d %c %d %c %d", &birth.month, &c, &birth.day, &c, &birth.year);

Answer 2

#include <stdio.h>
struct date {
    int month[1];
    int day[1];
    int year[1];

};

int calc_age (struct date birth, struct date current);


int main(void)
{
struct date birth, current;
char c;

printf("Input the birthdate (MM/DD/YY): ");
scanf("%d %c %d %c %d", birth.month, &c, birth.day, &c, birth.year);
printf("Input date to calculate (MM/DD/YY): ");
scanf("%d %c %d %c %d", current.month, &c,  current.day, &c, current.year);

printf("Age is %d years.\n", calc_age(birth, current));

return 0;

}

int calc_age (struct date birth, struct date current) {
int age;

if (birth.month[0] < current.month[0]) {
    age = (current.year[0] - birth.year[0]);
} else if (birth.month[0] > current.month[0]) {
    age = (current.year[0] - birth.year[0] - 1);
} else {
    if (birth.day[0] <= current.day[0]) {
        age = (current.year[0] - birth.year[0]);
    } else {
        age = (current.year[0] - birth.year[0] - 1);
    }
}

return age;
}

你应该在main

之前定义结构

如何解决 "parameter has incomplete type" 错误？

How to resolve "parameter has incomplete type" error?

c

arrays

struct

function