释放C结构体内部的char数组 [英] Free a char array that is inside a struct in C

问题描述

我有一个结构，其中包含一个字符串数组（char数组）和一个int以表示该数组的最大容量。

I have a struct that contains an array of strings (char arrays) and an int for the maximum capacity of the array.

typedef struct ArrayList
{
    char **array;
    int capacity;
}

使用malloc在自己的方法中初始化数组。

The array is initialized with malloc in its own method.

list->array = malloc(sizeof(char *) * templength);

然后将各个字符串初始化为

And the individual strings are initialized as

list->array[nextEmptyString] = malloc(sizeof(str));
strcpy(list->array[nextEmptyString], str);

我需要能够从内存中清除与该数组有关的所有内容，然后传递一个指向该数组的新指针数组，但是当我尝试在释放数组之前释放单个字符串时，它会扰乱新数组。

I need to be able to clear everything about that array from memory and then pass a new pointer to that array, however when I attempt to free the individual strings before freeing the array it scrambles the new array.

for (word = 0; word < list->capacity; word++)
    free(list->array[word]);
free(list->array);
list->array = newArray;

其中list是ArrayList，而newArray是字符串数组。如果我注释掉for循环，则代码可以正确运行，但是难道我不只是一堆孤立的字符串在内存中浮动吗？

Where list is an ArrayList and newArray is an array of strings. The code runs correctly if I comment out the for loop, but then don't i just have a bunch of orphaned strings floating around in memory?

预期的输出是什么例如将Pierre添加到L1 ... ，而我却得到将éc添加到L1 ...

The intended output is something like Adding Pierre to L1 ... and instead I get Adding �c� to L1 ...

推荐答案

在数组中分配字符串时，

When allocating the strings in the array,

malloc(sizeof(str))

仅为<$ c $分配足够的空间c> char * ，而不是它指向的字符串（除非 str 是普通数组而不是指针）。相反，请尝试

only allocates enough space for a char *, rather than the the string it points to (unless str was an ordinary array rather than a pointer). Instead, try

malloc(strlen(str) + 1)

为字符串中的字符分配足够的空间以及一个终止的null。

to allocate enough room for the characters in the string plus a terminating null.

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