我正在学习操作数组。我将从文件中读取的元素数据存储在main（）之外名为readInput（）的函数中的char和int数组中。数据读取：
D E D E D E E D E E D E E D E E D E
21 32 35 59 58 16 11 29
我试图调整两个数组的大小，以使用realloc排除数组中的垃圾：我的问题：
在main（）中打印char数组时，它包含正确的元素，但在数组末尾打印垃圾。我注意到它在readInput（）上正确打印。我做错了什么？
在realloc前后的readInput（）和main（）中，从int数组的文件中读取的元素是正确的，除了后面跟着垃圾。我做错了什么？
输出：
从readInput（）中打印-重新分配前的字符数组：D E D E D E E D E E D E
从readInput（）打印-重新分配前的Int数组：21 32 35 59 58 16 11 29-8421
50451-842150451-842150451-842150451-842150451-842150451-842150451-84215041-84215044
51-842150451-842150451-842150451-842150451-842150451-842150451-842150451-842150451
重新分配后从readInput（）字符数组打印：D E D E E D E E D E E D E
重新分配后从readInput（）打印-Int:21 32 35 59 58 16 11 29-336860
19-842150451 739749649 37763 4849560 4849264-842150451-842150451-842150451-
842150451-842150451-842150451-842150451-842150451-842150451-842150451-842
打印自main（）-字符数组（在重新分配之后）：D E D E D E D E D E D E E D E E D E═════════════
═══════════════════════════════════
════════════════════════════════════
打印自main（）-Int数组（重新分配后）：21 32 35 59 58 16 11 29-33686019-842150451 874388096 31426 6946712 6946416-842150451-842150451-842150451-842150451-842150451-842150451-842150451-842150451-842150451并继续
程序上下文：
读取的数据存储在main（）外部名为readInput（）的函数中，char by char/int by int分别存储在char和int数组中，这些数组分别通过main（）中的malloc声明和初始大小。
在数组中存储数据之后，我需要将数组的大小重新调整为文件中读取的数据的大小。
最后，要验证main也可以访问数组，请在main（）和readInput（）中逐个char和逐个int编写数组。
谢谢你的帮助。
修改了正确的工作代码，谢谢！
#include <stdio.h>
#include <ctype.h>
#include <string.h>
//prototypes
void openFile(char *fileNames, FILE **inputFilePointer);
void closeFile(FILE **inputFilePointer);
void readInput(char *choiceArray, int *valueArray, int *charArraySize, int *intArraySize, FILE **inputFilePointer);
void memCharReallocation(char **choiceArray, int requiredArraySize);//resize char array to what's actually required after reading the file
void memIntReallocation(int **valueArray, int intSize);//resize int array to what's actually required after reading the file
void main()
{
char *charArray =NULL;
int *valueArray;
int inputSize;
int charInputSize = 0;//size of elements read from file
int intInputSize = 0;//size of elements read from file
//file read/write variables
FILE *iFilePointer;//file pointer
char *filename = "inputFileTest.txt";
//open and read Files
openFile(filename, &iFilePointer);
//initial mem allocation to size char and int array
valueArray = (int*)malloc(sizeof(int) * 100);
if (valueArray == NULL)
{
printf("\nCould not allocate memory, exiting.\n");
exit(1);
}
charArray = (char*)malloc(sizeof(char) * 100);
if (charArray == NULL)
{
printf("\nCould not allocate memory, exiting.\n");
exit(1);
}
//read file and allocate to array
readInput(charArray, valueArray, &charInputSize, &intInputSize, &iFilePointer);
//print char array: Test I can read it here too
printf("\nPrint from main() - Char Array: ");
for (int j = 0; j<charInputSize; j++)
{
printf("%c ", charArray[j]);
}
//Print int array
printf("\nPrint from main() - Int Array: ");
for (int j = 0; j<intInputSize; j++)
{
printf("%d ", valueArray[j]);
}
}
//read data from file
void readInput(char *readCharArray, int *readValueArray, int *charArraySize, int *intArraySize, FILE **inputFilePointer)
{
int i, j = 0;//loop variables
char *pbuffer = NULL;//buffer to read input file
int bufferSize = 200;//max initial size for buffer
char *token = NULL;////tonize
char ch = NULL;//convert string char to char
int readingChar = 0;//flag we are reading char from file
//alloc memory to pbuffer
pbuffer = (char*)malloc(sizeof(char)*bufferSize);
if (pbuffer == NULL)
{
printf("\nCould not allocate memory, exiting.\n");
exit(1);
}
printf("Read Input From File: \n");
//store each element from file in struct variable
while (fgets(pbuffer, bufferSize, *inputFilePointer) != NULL)//read each line from file
{
j = 0;//reset array to subscript zero on each pass
//tokenize file data
for (token = strtok(pbuffer, " "); token != NULL; token = strtok(NULL, " "))
{
//char token
if (isalpha(token[0]))
{
ch = token[0];
readCharArray[j++] = ch;
readingChar = 1;//flag we are reading char from file to get length of array excl array garbage
}
//int token
else if (isdigit(token[0]))
{
readValueArray[j++] = atoi(token);
(*intArraySize)++;
}
else
{
printf("\nCan't read file\n");
exit(1);
}
}
if (readingChar)
{
readCharArray[j] = '\0';//remove excess cells on array
*charArraySize = strlen(readCharArray);//size of array
readingChar = 0;//end of reading char from file
}
}
//print char array: Test 1
printf("\nPrint from readInput() - Char Array before realloc: ");
for (int j = 0; j < *charArraySize; j++)
{
printf("%c ", readCharArray[j]);
}
//Print int array
printf("\nPrint from readInput() - Int Array before realloc: ");
for (int j = 0; j < *intArraySize; j++)
{
printf("%d ", readValueArray[j]);
}
memCharReallocation(&readCharArray, charArraySize);
memIntReallocation(&readValueArray, intArraySize);
printf("\nPrint from readInput() - Char Array after realloc: ");
for (int j = 0; j < *charArraySize; j++)
{
printf("%c ", readCharArray[j]);
}
printf("\nPrint from readInput() - Int After after realloc:");
for (int j = 0; j < *intArraySize; j++)
{
printf("%d ", readValueArray[j]);
}
}
void memCharReallocation(char **charArray, int requiredArraySize)//resize int array to what's actually required after reading the file
{
char *ptempArray = NULL;
ptempArray = (char*)realloc(*charArray, requiredArraySize * sizeof(char*));
if (ptempArray == NULL)
{
printf("Could not allocate memory, exiting");
exit(1);
}
else
*charArray = ptempArray;
if (ptempArray != *charArray)
free(ptempArray);
}
void memIntReallocation(int **valueArray, int intSize)//resize int array to what's actually required after reading the file
{
int *ptempArray = NULL;
ptempArray = (int*)realloc(*valueArray, intSize* sizeof(int*));
if (ptempArray == NULL)
{
printf("Could not allocate memory, exiting");
exit(1);
}
else
*valueArray = ptempArray;
if (ptempArray != *valueArray)
free(ptempArray);
}
void openFile(char *fileNames, FILE **inputFilePointer)
{
printf("\n\n");
//open files and error mssg
if ((*inputFilePointer = fopen(fileNames, "r")) == NULL) {
printf("Can't open input file %s\n", fileNames[1]);
exit(1);
}
}
void closeFile(FILE **inputFilePointer)
{
//close files
fclose(*inputFilePointer);
}
最佳答案
首先，警告是不可忽视的。
void main(char *argv) {
...
argv = ...;
应该已经提出一个（叮当甚至给了一个错误！）因为它不符合C。它应该是：
int main() {
...
char *filename = ...;
如果不使用argv，请不要声明它，并避免对命令行参数以外的任何内容使用
argv。下一步：
for (int j = 0; j < charArray!=NULL; j++)还将引发大量警告。首先比较j和charArray（已经没有定义的行为）。在看到结果之后，j < charArray碰巧是真的（C中的值1），并且您将其与NULL（avoid *）进行比较！1 != 0总是正确的，你得到了一个永无止境的循环。for (int j = 0; j < charSize || readValueArray[j] != NULL; j++)还应发出警告：readValueArray[j]是一个int并且NULL是一个void *。此外，测试readValueArray[j]到0是没有用的，因为您从未初始化分配的内存。最后，resize不会从数组中移除垃圾，它会在内存中的某个位置重新分配具有所请求大小的数组，并且如果访问超过分配的内存，则只调用未定义的行为。在C语言中没有办法知道数组的大小，这是程序员的工作来关心它。
所以你有两种可能的方法：
将数组的实际大小作为
readInput的（输出）参数传递：void readInput(char *choiceArray, int *valueArray, FILE **inputFilePointer,
int *choiceArraySize, int *valueArraySize)
或者使用特殊值（例如0）作为结束标记。
请注意警告！