#include <stdio.h>
#include <stdlib.h>
#include <string.h>
char** AllocateShoppingList(int numFoods);
char* AllocateItem();
int DetermineNumberOfCandy(char** list, int numFoods);

int main()
{
  
   char** stringArray;// pointer to pointers
   char* words; //pointer to char array
   //1. ask the user how many foods are on their list
   int foods;
   printf("How many foods on the shopping list?\n");
   scanf("%d", &foods);
   //2. call the AllocateShoppingList function and store the result
   stringArray = AllocateShoppingList(foods);   
   //3. for X times (user's previous input), call the AllocateItem function 
   //       and store the result in the list of pointers (step 2)
   for(int i =0;i < foods; i++){
   words = AllocateItem();
   stringArray[i] = words;}

  //strcpy(stringArray[i],words); why not work?
   
   //4. call the DetermineNumberOfCandy function, and print the result
   printf("Candy appeared this many times: %d\n",DetermineNumberOfCandy(stringArray, foods)); 
   //5. free up all of the pointers that are held by the shopping list
   //6. free up the shopping pointer itself
   free(words);
   free(stringArray);
   
}

int DetermineNumberOfCandy(char** list, int numFoods)
{
   //0. setup a counter variable
   int counter = 0 ;
   //1. for each pointer in the shopping list:
   //1a.   compare the string at the pointer's address to "candy"
   
   for(int i =0; i< numFoods; i++)
   if (strcmp(list[i],"candy")==0)
     // why you dont have to dereference it
     // this concept works with single pointers
     // does it work with double or tripple pointers as long as it orignally points to the string?
     
   counter++;
   
   //1b.   if it is candy, then tick up the counter variable
   //2. return the counter variable
   return counter;
}

char** AllocateShoppingList(int numFoods)
{
   
   return calloc(numFoods, sizeof(char*));
   //1. allocate memory that can hold X pointers (X = numFoods)
   //2. return the memory address holding this pointer to pointers
}

char* AllocateItem()
{
   char* wordPtr;
   char word[100];
   //1. get a word from the user that is max 100 characters
 
   scanf("%s", word);
   //2. determine how large the word actually is
   wordPtr = calloc(strlen(word)+1,sizeof(char));
   strcpy(wordPtr, word);
   //3. allocate memory that is just enough to hold the word
   return wordPtr;
   //4. copy the user's word into the new memory location
   //5. return the memory address holding the word
}

在这段代码中，我们必须最后得到一个shopping，然后打印出candy在购物清单中出现的次数。为了做到这一点，我们必须分配足够的内存来保存用户希望在购物清单中出现的单词（字符串）。然后，为每个项目分配足够的内存来存储单词。

这份声明对我来说毫无意义

**char** stringArray; **

根据我的理解，双指针是一个数组，数组中的元素包含一个指向字符串地址的指针。
因此，我认为我们必须像这样声明双指针：

字符串数组[];

像这样的东西，但那是行不通的

所以我想知道如果我们不加括号代码怎么知道它是一个指针数组

我试着用数组声明双指针，但无法让它工作，也不能弄清楚它是否可能。