感谢您抽出宝贵时间阅读我的问题, 我已经看了几个类似的问题,在这种情况下他们似乎没什么帮助 虽然可以帮助其他类似的麻烦:
C: Incompatible types?
Struct as incompatible pointer type in C
Incompatible Types Error with Struct C
我试图在c(-std = c99)中创建一个简单的链表结构, 我的结构在这一点上相当通用:
typedef struct
{
int count;
char* word;
struct node *nextNode;
}node;
然后在一个函数中我有一个" root"或者"头部"节点:
node *root;
root = (node *) malloc(sizeof(node));
我尝试稍后在函数中将node
分配给根节点nextNode
,如下所示:
if(root->nextNode == 0)
{
root->nextNode = foo;
}
导致错误:
"从类型struct node*
分配到类型node
时出现错误不兼容类型
&foo
并未改善情况,而是导致lvalue required as unary
样式错误。
以下是我的问题的背景:
#include <stdio.h>
#include <malloc.h>
#include <string.h>
typedef struct
{
int count;
char* word;
struct node *nextNode;
}node;
node makenode(char *word)
{
node x;
x.word = word;
x.count = 1;
return x;
}
void processInput(int threshold, const char* filename)
{
node *root;
root = (node *) malloc(sizeof(node));
root->nextNode = 0;
char* word;
while(fgets(word, 29, stdin) != NULL){
if(root->nextNode == 0)
{
root->nextNode = makenode(word);
}
答案 0 :(得分:2)
问题
typedef struct // make an alias for a structure with no tag name
{
int count;
char* word;
struct node *nextNode; // with a pointer to struct node (which does not exit)
}node; // name the alias node
解决方案
typedef struct node // make an alias for a structure with tag name node
{
int count;
char* word;
struct node *nextNode; // with a pointer to struct node (which is this one)
}node; // name the alias node
答案 1 :(得分:0)
尝试此代码
#include <stdio.h>
#include <malloc.h>
#include <string.h>
typedef struct node //should give a name for this
{
int count;
char* word;
struct node *nextNode;
}node;
static node *makenode(char *word) //start with static and returning type is node* because we are storing this output in root->nextNode which is *node pointer
{
node x;
x.word = word;
x.count = 1;
return x;
}
void processInput(int threshold, const char* filename)
{
node *root;
root = (node *) malloc(sizeof(node));
root->nextNode = NULL; //pointer values should initialised to NULL not 0
char* word;
while(fgets(word, 29, stdin) != NULL){
if(root->nextNode == NULL) ////pointer values should initialised to NULL not 0
{
root->nextNode = makenode(word);
}
}