c - 错误 : too few arguments to function `printDay' (C language)

Question

问题

我是 C 的新手，尝试编译它 (GCC) 时出现此错误:

error: too few arguments to function `printDay'

我的问题是:

1. 这是什么意思？
2. 我该如何解决这个问题？

P.S 这不是我的完整代码，这只是我遇到的这个错误。提前致谢。

代码

#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include <time.h>

#define MAX_DAYS 31
#define MIN_DAYS 1
#define MAX_MONTHS 12
#define MIN_MONTHS 1

enum monthsOfYear
{
    jan = 1,
    feb,
    mar,
    apr,
    may,
    jun,
    jul,
    aug,
    sep,
    oct,
    nov,
    dec
};

enum daysOfWeek
{
    sun = 1,
    mon,
    tue,
    wed,
    thu,
    fri,
    sat
};

int input();
void check(int month, int day);
void printDay(int month, int day, int firstDay);

int main()
{
    printf("Hello! Welcome to the day calculator!\n");
    printDay(input());
    return (0);
} 

/*this function takes the input from the user
input: none
output: the first day
*/ 
int input()
{
    enum daysOfWeek day = 0;
    enum monthsOfYear month = 0;
    
    int firstDay = 0;
    
    printf("Enter month to check: (1-jan, 2-feb, etc) ");
    scanf("%d", &month);
    printf("Enter day to check: ");
    scanf("%d", &day);
    check(month,day);
    printf("Enter the weekday of the 1st of the month: (1-Sunday, 2-Monday, etc) ");
    scanf("%d", &firstDay);
    
    return firstDay;
}

/*
this function checks the validity of the input
input: day, month
output: none
*/
void check(int month, int day)
{
    if(month > MAX_MONTHS || month < MIN_MONTHS && day > MAX_DAYS || day < MIN_DAYS)
    {
        printf("Invalid input, try again\n");
        input();
    }
    if (month == feb && day > 28)
    {
        printf("Invalid input, try again\n");
        input();
    }
    if (month == jan && day > 31)
    {
        printf("Invalid input, try again\n");
        input();
    }
}

void printDay(int month, int day, int firstDay)
{
    int date = 0;
    date = day - firstDay;
    switch(day)
    {
        case sun:
        printf("%d.%d will be a Sunday", day, month);
        break;
        
        default: 
        break;
    }
}

Answer 1

1. What does it mean?

“error: too few arguments to function 'printDay'” 表示您在此处调用 printDay 时传递了错误数量的参数:

printDay(input());

您正在传递一个参数，但您对 printDay 的声明显示它需要 3 个参数:

void printDay(int month, int day, int firstDay);

2. How do I fix this?

您可以通过传递正确数量的参数来修复它，例如:

int month = ...;
int day = ...;
int firstDay = ...;
printDay(month, day, firstDay);