与从函数返回结构类型有关的错误

Question

我无法弄清楚为什么gcc认为我试图给一个结构类型分配一个整数。下面的代码是尝试将其他较短代码的功能组合起来，这些代码编译和工作得很好。

#include <stdio.h> 
#include <stdbool.h> 
struct date 
{ 
    int month; 
    int day; 
    int year; 
}; 
struct time { 
    int hour; 
    int minutes; 
    int seconds; 
}; 
struct dateAndTime { 
    struct date combinedDate; 
    struct time combinedTime; 
    }; 
void clockKeeper(struct dateAndTime dtAnTm) 
    { 
    //struct time testTime [] = { { 11, 59, 59 } , {12, 00, 00} , {1, 29, 59} , {23, 59, 59} , {19, 12, 27} }; 
    struct time testTime[] = { 
     {.hour = 11, .minutes = 59, .seconds = 59}, 
     {.hour = 12, .minutes = 00, .seconds = 00}, 
     {.hour = 1, .minutes = 29, .seconds = 59}, 
     {.hour = 23, .minutes = 59, .seconds = 59}, 
     {.hour = 19, .minutes = 12, .seconds = 27} 
     }; 
    int i; 
    struct time midNight = { 12, 00, 00}; 
    printf ("Here is what is in Midnight :%i:%i:%i \n", midNight.hour, midNight.minutes, midNight.seconds); 
    for (i = 0; i < 5; i++) 
     { 

     printf("Time is: %.2i:%.2i:%.2i\n", testTime[i].hour, testTime[i].minutes, testTime[i].seconds); 
     testTime[i] = timeUpdate (testTime[i]); 
     printf("....one second later%.2i:%.2i:%.2i\n", testTime[i].hour, testTime[i].minutes, testTime[i].seconds); 
     //if (testTime[i].hour > midNight.hour) 
      // testTime[i]= dateUpdate (testTime[i]); 
     } 
    } 
struct time timeUpdate (struct time now) 
    { 
    ++now.seconds; 
    if (now.seconds == 60) { // next minute 
     now.seconds = 0; 
     ++now.minutes; 
     if (now.minutes == 60) { 
     now.minutes = 0; 
     now.hour++; 
     if (now.hour == 24) // midnight 
     now.hour = 0; 
     } 
     } 
    return now; 
    } 
struct date dateUpdate (struct date today) 
{ 
    struct date tomorrow; 
    int numberOfDays (struct date d); 

    if (today.day != numberOfDays (today)) { 
     tomorrow.day = today.day + 1; 
     tomorrow.month = today.month; 
     tomorrow.year = today.year; 
} 
else if (today.month == 12) { 
    tomorrow.day = 1; 
    tomorrow.month = 1; 
    tomorrow.year = today.year + 1; 
} 
else { 
    tomorrow.day = 1; 
    tomorrow.month = today.month + 1; 
    tomorrow.year = today.year; 
} 
return tomorrow; 
} 
int numberOfDays (struct date d) 
{ 
int days; 
bool isLeapYear (struct date d); 
const int daysPerMonth[12] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }; 
if (isLeapYear (d) == true && d.month == 2) 
    days = 29; 
else 
    days = daysPerMonth[d.month - 1]; 
return days; 
} 
// Function to determine if it's a leap year 
bool isLeapYear (struct date d) 
{ 
bool leapYearFlag; 
if ((d.year % 4 == 0 && d.year % 100 !=0) || d.year % 400 == 0) 
    leapYearFlag = true; // It's a leap year 
else leapYearFlag = false; // Not a leap year 
return leapYearFlag; 
} 
int main (void) 
    { 
void clockKeeper(struct dateAndTime dtAnTm); 
bool isLeapYear (struct date d); 
int numberOfDays (struct date d); 
struct time timeUpdate(struct time now); 
struct date dateUpdate (struct date today); 
return 0; 
    } 

我得到以下错误：

gcc .c -o 
.c: In function 'clockKeeper': 
.c:28:22: error: incompatible types when assigning to type 'struct time' from type 'int' 
      testTime[i] = timeUpdate (testTime[i]); 
        ^
.c:31:23: error: incompatible types when assigning to type 'struct time' from type 'int' 
      testTime[i]= dateUpdate (testTime[i]); 
       ^
.c: At top level: 
.c:34:13: error: conflicting types for 'timeUpdate' 
struct time timeUpdate (struct time now) 
      ^
.c:28:24: note: previous implicit declaration of 'timeUpdate' was here 
      testTime[i] = timeUpdate (testTime[i]); 
         ^
.c:49:13: error: conflicting types for 'dateUpdate' 
struct date dateUpdate (struct date today) 
      ^
.c:31:25: note: previous implicit declaration of 'dateUpdate' was here 
      testTime[i]= dateUpdate (testTime[i]); 
         ^
make: *** [] Error 1 

我已经更新结构，原料与材料[]数组和注释掉dateUpdate（）调用，因为我相信是不正确。我仍然看到关于类型不匹配的错误：

.c:28:22: error: incompatible types when assigning to type 'struct time' from type 'int' 
      testTime[i] = timeUpdate (testTime[i]); 
        ^

Answer 1

在clockKeeper几个问题：

1. 一个初始化struct time testTime[]正确的做法是这样的：

   struct time testTime[] = { 
        {.hour = 11, .minutes = 59, .seconds = 59}, 
        {.hour = 12, .minutes = 00, .seconds = 00}, 
        {.hour = 1, .minutes = 29, .seconds = 59}, 
        {.hour = 23, .minutes = 59, .seconds = 59}, 
        {.hour = 19, .minutes = 12, .seconds = 27} 
   }; 
   

2. 通话dateUpdate(timeTime[i])类型不匹配。你的逻辑在这里不正确。

Answer 2

struct time testTime [] = { 11, 59, 59, 12, 00, 00, 1, 29, 59, 23, 59, 59, 19, 12, 27 }; 

是不正确，因为RHS是int秒的阵列。您可以使用：

// Using multiple lines makes the code readable 
struct time testTime [] = { {11, 59, 59}, 
          {12, 00, 00}, 
          {1, 29, 59}, 
          {23, 59, 59}, 
          {19, 12, 27} };