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c - 从不兼容的指针类型传递参数 (C)

转载 作者:行者123 更新时间:2023-11-30 15:08:55 25 4
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我需要创建一个程序,将硬编码输入列出到不同的文件中。我在 fprintf 部分遇到问题。

The full program is listed in the back.

我已经和我的老师谈过了,她标记了

   else
{
print_rmchr(str1, chr1);
print_rmchr(str2, chr2);
print_rmchr(str3, chr3);
print_rmchr(str4, chr4);
print_rmchr(str5, chr5);

if (fclose(filePtr) != 0)
printf("Unable to close the data file.\n");
}

if (fprintf("The string '%s' will be removed from '%c' characters. \n\n", str, ch) < 0)
printf("Unable to print non-modified string with a modifying character. \n");

rmchr(str, ch);

if (fprintf("New modified string is: '%s'. \n\n", str) < 0)
printf("Unable to print new modified string. \n");

作为我作业中代码的错误部分。

我在starkoverflow上查看了类似的问题,发现我必须将filepointer放在fprintf之前。我的第二 block 错误代码现在看起来像这样:

if (fprintf(filePtr, "The string '%s' will be removed from '%c' characters. \n\n", str, ch) < 0)
printf("Unable to print non-modified string with a modifying character. \n");

rmchr(str, ch);

if (fprintf(filePtr, "New modified string is: '%s'. \n\n", str) < 0)
printf("Unable to print new modified string. \n");

然后编译器对我大喊大叫,因为我不知道为什么会有文件指针,所以我也将其修复为

print_rmchr(filePtr, str, chr);

但随后它开始对我大喊大叫,好像“从不兼容的指针类型传递参数”。它看起来适合我,但我想缺少一些东西(?)。

我的完整计划:

/*
* A simple program to remove certain characters from the given strings
*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int main () {

// print array before and after editing array
void print_rmchr (char str[], char ch);

char str1[20] = "abracadabra"; //string #1
char str2[20] = "abracadabra"; //string #2
char str3[20] = "abracadabra"; //string #3
char str4[20] = "aaaa"; //string #4
char str5[20] = "aaaa"; //string #5

char chr1 = 'a'; //character #1
char chr2 = 'b'; //character #2
char chr3 = 'n'; //character #3
char chr4 = 'a'; //character #4
char chr5 = 'n'; //character #5

FILE *filePtr;

filePtr = fopen("rmchr.out", "w");

if( filePtr == NULL)
printf("Unable to open the data file.\n");

else
{
print_rmchr(filePtr, str1, chr1);
print_rmchr(filePtr, str2, chr2);
print_rmchr(filePtr, str3, chr3);
print_rmchr(filePtr, str4, chr4);
print_rmchr(filePtr, str5, chr5);

if (fclose(filePtr) != 0)
printf("Unable to close the data file.\n");
}
return 0;
}

//remove certain characters from array
void rmchr(char str[], char ch) {
int i, j = 0; //loop variable
int size; //lengh
char new_str[20]; //new array

size = strlen(str);

for (i = 0; i < size; i++) {
if (str[i] != ch) {
new_str[j] = str[i];
j++;
}
}
new_str[j] = '\0';

strcpy(str, new_str);
}

// print array before and after editing array
void print_rmchr (char str[], char ch){

//remove certain characters from array
void rmchr(char str[], char ch);

if (fprintf(filePtr, "The string '%s' will be removed from '%c' characters. \n\n", str, ch) < 0)
printf("Unable to print non-modified string with a modifying character. \n");

rmchr(str, ch);

if (fprintf(filePtr, "New modified string is: '%s'. \n\n", str) < 0)
printf("Unable to print new modified string. \n");
}

/* In case you will need user input:
//USER INPUT
printf("Enter the string : \n");
gets(str);

printf("Enter character which you want to delete : \n");
scanf("%ch", &ch);

print_rmchr(str, ch);
*/

最终更正版本:

/*
* A simple program to remove certain characters from the given strings
*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define MAX 20

int main () {

// print array before and after editing array
void print_rmchr (FILE *filePtr, char str[], char ch);

char str1[MAX] = "abracadabra"; //string #1
char str2[MAX] = "abracadabra"; //string #2
char str3[MAX] = "abracadabra"; //string #3
char str4[MAX] = "aaaa"; //string #4
char str5[MAX] = "aaaa"; //string #5

char chr1 = 'a'; //character #1
char chr2 = 'b'; //character #2
char chr3 = 'n'; //character #3
char chr4 = 'a'; //character #4
char chr5 = 'n'; //character #5

FILE *filePtr = NULL; // best to always initialize stack variables

if( NULL == (filePtr = fopen("rmchr.txt", "w") ) )
{
// output your message, plus the system error message
perror("fopen rmchr.out for write failed");

// exit() and EXIT_FAILURE in 'stdlib.h'
exit(EXIT_FAILURE);
}
// implied else, fopen successful

print_rmchr(filePtr, str1, chr1);
print_rmchr(filePtr, str2, chr2);
print_rmchr(filePtr, str3, chr3);
print_rmchr(filePtr, str4, chr4);
print_rmchr(filePtr, str5, chr5);

if (fclose(filePtr) != 0)
printf("Unable to close the data file.\n");

return 0;
}

//remove certain characters from array
void rmchr(char str[], char ch)
{
size_t i; //loop variable
int j = 0; //loop variable
char new_str[MAX]; //new array

for (i = 0; str[i]; i++) {
if (str[i] != ch) {
new_str[j] = str[i];
j++;
}
}
new_str[j] = '\0';

strcpy(str, new_str);
}

// print array before and after editing array
print_rmchr (FILE *filePtr, char str[], char ch){

//remove certain characters from array
void rmchr(char str[], char ch);

if (fprintf(filePtr, "All instances of character %c will be removed from string '%s. \n\n", ch, str) < 0)
printf("Unable to print non-modified string with a modifying character. \n");

rmchr(str, ch);

if (fprintf(filePtr, "New modified string is: '%s'. \n\n", str) < 0)
printf("Unable to print new modified string. \n");
}

/* In case you will need user input:
//USER INPUT
printf("Enter the string : \n");
fgets(str);

printf("Enter character which you want to delete : \n");
scanf("%ch", &ch);
//need to check the returned value of scanf

print_rmchr(str, ch);
*/

最佳答案

当您想要向函数传递更多或其他参数时,必须修改调用和函数定义,以便它们彼此兼容。更改自

void print_rmchr (char str[], char ch);

至:

void print_rmchr (FILE *filePtr, char str[], char ch);

事实上,符号 filePtrmain 的本地符号,在 print_rmchr 中是未知的。

关于c - 从不兼容的指针类型传递参数 (C),我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/37033236/

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