c - C编程:警告:类型冲突？

编译main.c时出错
错误显示：

functions.c:27:6: warning: conflicting types for 'secondfunction' [enabled by default]
functions.c:23:2: note previous implicit declaration of 'secondfunction' was here

（我的程序有一个名为main.c、header.h和functions.c的文件）
主要c：

#include "header.h" /*Includes the header file*/

int main(void) /*Starts the main function.*/
{
    course();
    firstfunction(filename,fileextension,fp,MAX_SIZE);
    /*
    thirdfunction();
    fourthfunction();
    fifthfunction();
    sixthfunction();
    */
    return 0;
} /*Ends the main function.*/

页眉.h：

#include <stdio.h>
#include <string.h>
#include "functions.c"

#define MAX_SIZE 50

struct records
    {
    double euid;
    char firstname[MAX_SIZE];
    char lastname[MAX_SIZE];
    float gpa;
    };

void course(void);
void firstfunction(char filename[],char fileextension[],FILE* fp,int SIZE);
void secondfunction(FILE* fp);

struct records people;
FILE* fp;
char filename[MAX_SIZE],fileextension[MAX_SIZE];

功能c：

void course(void)
{
    printf("\n\n\n\n\nDepartment: CSCE\nCourse number: 1030\nProgram number: Homework 3\nName: xxxxxxxxxxxxxx\nEUID: xxxxxxxxxxxxx\nEmail: xxxxxxxxx\n\n\n\n\n");
}

void firstfunction(char filename[],char fileextension[],FILE* fp,int SIZE)
{
    printf("Please enter the file name (ex:filename)\n"); /*Asks for the name and the extension*/
    scanf("%s",filename);

    printf("Please enter the file extension (ex:.txt)\n");
    scanf("%s",fileextension);

    strcat(filename,fileextension); /*Puts them together with strcat*/
    printf("%s\n",filename);

    fp=fopen(filename,"r");
    secondfunction(fp);
    fclose(fp);
} /*End of the first function*/

void secondfunction(FILE* fp)
{

} /*End of the second function.*/

谢谢你们的帮助！!
我不认为变量被传递给函数，我认为我是从函数内部调用函数。我该怎么解决？

最佳答案

从header.h中删除此行#include "functions.c"，并在functions.c中包含header.h

关于c - C编程:警告:类型冲突？，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/20013004/