c - 指向结构体中 char 的指针，段错误

Question

所以我创建了一个结构体，其中变量之一是指向动态字符数组的指针。所以我把它实现为一个指向指针的指针。然后我使用一个单独的函数来初始化结构:

#include<stdio.h>
#include<stdlib.h>
//create a struct
typedef struct{
    //use a double pointer
    char **dynamicArray; 
    int size;
    int topValue; 
}Stack; 

/*
    Inintializes the stack
    Dyanmic Array will have a size of 2
*/
void intializeStack(Stack *stack){
    stack->size = 2; 
    stack->topValue = 0;

    //create a dyanmic array of char and set the value in the struct to the address for the newly created array
    char *dyanmic; 
    dyanmic = malloc(2 * sizeof(char)); 
    stack->dynamicArray = &dyanmic; 
}
int main(){

    Stack stack; 
    intializeStack(&stack);

    printf("stack.size: %d\n", stack.size);
    printf("stack.topValue: %d\n", stack.topValue); 
    int i; 
    for (i = 0; i < stack.size; i++){
        *(stack.dynamicArray)[i] = 'r'; 
        printf("%d value of the dynamic array: %c\n", i, *(stack.dynamicArray)[i]);
    }

    printf("Check if the stack is empty: %s\n",isEmpty(&stack)?"true":"false");

    return 0; 
}

数组的大小最初设置为 0。问题是当我尝试访问数组中的第二个元素时，出现段错误错误。

Segmentation fault (core dumped)

我在实现过程中做错了什么吗？

Answer 1

以下构造令人困惑并且最终是错误的:

for (i = 0; i < stack.size; i++){
      *(stack.dynamicArray)[i] = 'r'; 
      printf("%d value of the dynamic array: %c\n", i, *(stack.dynamicArray)[i]);
}

您实际上通过这种结构引用了**的第一级。试试这个:

for (i = 0; i < stack.size; i++){
    stack.dynamicArray[0][i] = 'r';
    printf("%d value of the dynamic array: %c\n", i, stack.dynamicArray[0][i]);
}