c - 结构数组测试时循环未触发

Question

我刚刚开始探索 C，所以我会很感激任何代码风格的建议。然而，我的具体问题是理解为什么我的 else if 条件没有被触发。正如您在评论中看到的，我意识到我的 loop->word 似乎从未初始化过，但第二次通过 for 循环 我认为至少应该加一个字吗？

代码:

 typedef struct node{
     char word[15];
     int count;
 } node;


 int main(int argc, char *argv[]){
     int word_size = 500, dict_size=10;
     char words[word_size];

     // main prompt
     printf("Enter some words: ");
     fgets(words, word_size, stdin);

     // create a list of nodes, and iterator through array
     struct node dict[dict_size];
     struct node *head = dict;
     struct node *loop = dict;

     // pointer for tokenization, starts at [0] until delimiter
     char *pch;
     pch = strtok(words, " ");
     // TODO: dict[0] so that last is equal to 1, and can use that as max loop?

     // keep track of how many nodes have been updated
     int i, j, last = 0;

     while(pch != NULL){
         printf("pch == %s\n", pch); // this works

         for(i=0; i<dict_size; i++, loop++) {
             printf("inner = %d\n", i); // this works
             printf("loop->word == %s\n", loop->word); // realize i'm testing against nonsense?

             if(loop->word == pch){
             // loop through each dict element, looking for matching word
             // increment the value pointed to by loop->count
                 printf("%s was found in dict[%d], incrementing counter", loop->word, loop->count);
                 loop->count = loop->count + 1;
                 break;

             } else if(i == dict_size){
             // key doesn't exist so update the next struct
                 printf("adding %s, with count 1.\n", pch);
                 strcpy(dict[last].word, pch);
                 dict[last].count = 1;
                 last++;
             }
         }
         // lastly move token, and reset pointer @ head of the dictionary
         pch = strtok(NULL, " ");
         loop = head;
     }

     // set pointers to null?
     loop = NULL;
     head = NULL;
     printf("done");

编辑:对代码墙感到抱歉，不确定解决 C 问题所需的最少代码是什么。

Answer 1

• 在条件为 i<dict_size 的 for 循环内您如何期望它等于 dict_size if 是 for 循环体中唯一不递增的地方。

• 您可能想要的是，循环结束后 - 检查是否 i == dict_size那么你就可以确定它没有被发现。在 for 循环中，您正在检查 i == dict_size这将在它之外。

• 还有loop->word == pch正在比较两个指针 - 但您想比较两个字符串 - 这将使用 strcmp 来完成。所以代码的结构将是

  for(i = ..; i < dict_size ; ... ){
     if(strcmp(loop->word, pch) == 0){
        /*  found */
     }
     ...
  }
  if( i == dict_size){
     /* not found */
  }
  

• fgets应检查返回值以检查函数调用的失败或成功。这个级别的错误检查很重要。