我想通過引用在C中傳遞一個結構,以便我可以修改函數內的值。這是迄今爲止的代碼,但它會產生一些警告和一個錯誤。C - 通過引用傳遞結構
的main.c
#include <stdio.h>
#include "myfunctions.h"
#include "structures.h"
int main(int argc, char const *argv[] {
struct MyStruct data;
data.value = 6;
printf("Before change: %d\n", data.value);
changeData(data);
printf("After change: %d\n", data.value);
}
myfunctions.c
#include "structures.h"
void changeData(MyStruct data) {
data.value = 7;
}
myfunctions.h
#ifndef MyStruct
#define MyStruct
void changeData(MyStruct data);
#endif
structures.h
typedef struct {
int value;
} MyStruct;
個錯誤生產
In file included from main.c:2:0:
myfunctions.h:4:1: warning: parameter names (without types) in function declaration
void changeData(MyStruct data);
^
In file included from main.c:3:0:
structures.h:5:1: warning: unnamed struct/union that defines no instances
} MyStruct;
^
main.c: In function ‘main’:
main.c:9:5: error: ‘data’ undeclared (first use in this function)
data.value = 6;
^
main.c:9:5: note: each undeclared identifier is reported only once for each function it appears in
'空隙changeData(MYSTRUCT *數據)'和'changeData( &數據)' –
如果你想傳遞一個指向結構的指針,你需要明確地做到這一點。 –
確保您在頁面右側檢查** Related **。你的頭銜出現很多次。 –