在 C 中以 void 指针的形式存储通用数据

Question

I am trying to use void pointer to store generic data in C language

这是存储通用数据类型的结构

 struct Node{
        int id;  // Id of the node 
        void *data; // Variable Which stores data
    };

我正在通过这种方法存储数据

int graph_setnode_data(graph_t *graph,int id,void *data){
    struct Node *node = getnode(graph,id);
    if(node != NULL){
        node->data = data;
        return 0;
    }
    return 1;
}

并通过

访问数据

void* graph_getnode_data(graph_t *graph,int id){
    struct Node *node = getnode(graph,id);
    if(node != NULL){
        return node;
    }
    return NULL;
}

下面是我如何使用这些方法

struct Person{
    char *name;
    int age;
};
int main(){
    struct Person *person = malloc(sizeof(struct Person));
    person->name = "Goutam";
    person->age = 21;

    graph_t *graph = graph_init(2);
    graph_createpath(graph,0,1);
    graph_createpath(graph,1,0);
    graph_setnode_data(graph,0,(void *)person);
    struct Person *data =(struct Person *) graph_getnode_data(graph,0);
    printf("%d\n",data->age);
    graph_destroy(graph);
    return 0;
}

但我得到的输出是：

38162448

Answer 1

您返回的是节点，而不是节点中存储的数据：

void* graph_getnode_data(graph_t *graph,int id){
    struct Node *node = getnode(graph,id);
    if(node != NULL){
        return node->data; // <---- This should fix the bug.
    }
    return NULL;
}

在 C 中以 void 指针的形式存储通用数据

Storing generic data in the form of void pointer in C

c

pointers

void-pointers