请求成员而不是结构或联合，但这是结构

Question

this code is a binary search tree I'm doing for my school assignment.

#include "binary_tree.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define MAXLEN 10


Node* create_tree() {

return NULL;

}

void insert_tree(Node** root, char* nname, char* number) {


    if (*root==NULL){
        Node* node = (Node *)malloc(sizeof(Node));

        strncpy(node->name , nname, MAXLEN);
        strncpy(node->number , number, MAXLEN);

        node->left = node->right = NULL;
        *root = node;
        return;

    }


    if (strncmp(*root->name, nname, MAXLEN)) {

        insert_tree(&(*root)->left, nname, number);

    } else {

        insert_tree(&(*root)->right, nname, number);
    }
}

void preorder(Node* node, int level){
    int i;
    if (node==NULL){
        //printf("null\n");
        return;

    }
    for (i = 0; i<level; i++) {
        printf("  ");
    }
    printf("%s %d\n", node->name, level);

    preorder(node->left, level + 1);
    preorder(node->right, level + 1);

}

This is my Full code. Well I deleted not necessary bits of codes, but thats all I need right know..

typedef struct t_node {
    char name[MAXLEN + 1];
    char number[MAXLEN + 1];
    struct t_node *left;
    struct t_node *right;

} Node;

and this is the Node type I'm using.

at the insert_tree, inserting one node is OK.

but when I use strncmp, it get errors.

"Request for member in something not a structure or union"

isn't root a Node Struct?

I don't get why I get errors.

Answer 1

See operator precedence , where -> is having precedence over * . You should use (*root)->name as argument to your strncmp() call.