如何將字符串數組傳遞給C中的函數？

Question

所以我有這個函數（makeStruct）能夠接受一個字符串並打印出結構的元素。 例如，我傳入的字符串是"a = 2.b, 1.d, 3.d; 4.o; milk cheese" ，它通過我的函數將每個數字，字母和單詞存儲到相應的中我創建的struct元素。 這非常好，但只有一個字符串：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

struct stopPoints {
    int  weights[10];
    char connectingPoints[10];
    char *items[30];
    int startBool;
};


void makeStruct(char str[]){

    struct stopPoints myPoint;
    char *arr[30];
    char * pch;
    pch = strtok (str," ;=,.-");
    arr[0] = pch;
    int i=0;


  for (pch; pch != NULL; i++){
    pch = strtok (NULL, " ;=,.-");
    arr[i+1] = pch;
    //printf("%s\n", arr[i]);

  }
  printf("\n");
  char letters[10];
  int numbers[10];
  char *strings[10] = {NULL};
  int p, iter=0, iter2=0, iter3=0, val[10];
  for (p=0; arr[p] != NULL; p++){
      //if its a string
      if (isalpha(*arr[p]) && strlen(arr[p]) >=2 ){
        //printf("%s is a string\n", arr[p]);
        myPoint.items[iter] = arr[p];
        iter++;
      }
      //if its just a letter
      else if (isalpha(*arr[p]) && strlen(arr[p]) ==1){
        //printf("%s is a letter\n", arr[p]);
        letters[iter2] = *arr[p];
        myPoint.connectingPoints[iter2] = letters[iter2];
        iter2++;
        //printf("letter\n");
      }
      //if its a number
      else if (isdigit(*arr[p])){
        //printf("%s is a number\n", arr[p]);
        val[iter3] = atoi(arr[p]);
        myPoint.weights[iter3] = val [iter3];
        iter3++;
      }
  }



  printf("%s %s\n",  myPoint.items[0], myPoint.items[1]);

}


int main ()
{
        char str[] = "a = 2.b, 1.d, 3.d; 4.o; milk cheese";
        makeStruct(str);
  return 0;
}

現在，我希望能夠將多個字符串傳遞給此函數。 這就是我的問題所在。 我嘗試了幾種不同的方法，但我不明白我哪里出錯了。 請看下面的代碼：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

struct stopPoints {
    int  weights[10];
    char connectingPoints[10];
    char *items[30];
    int startBool;
};


void makeStruct(char str[]){

    struct stopPoints myPoint;
    char *arr[30];
    char * pch;
    pch = strtok (str," ;=,.-");
    arr[0] = pch;
    int i=0;


  for (pch; pch != NULL; i++){
    pch = strtok (NULL, " ;=,.-");
    arr[i+1] = pch;
    //printf("%s\n", arr[i]);

  }
  printf("\n");
  char letters[10];
  int numbers[10];
  char *strings[10] = {NULL};
  int p, iter=0, iter2=0, iter3=0, val[10];
  for (p=0; arr[p] != NULL; p++){
      //if its a string
      if (isalpha(*arr[p]) && strlen(arr[p]) >=2 ){
        //printf("%s is a string\n", arr[p]);
        myPoint.items[iter] = arr[p];
        iter++;
      }
      //if its just a letter
      else if (isalpha(*arr[p]) && strlen(arr[p]) ==1){
        //printf("%s is a letter\n", arr[p]);
        letters[iter2] = *arr[p];
        myPoint.connectingPoints[iter2] = letters[iter2];
        iter2++;
        //printf("letter\n");
      }
      //if its a number
      else if (isdigit(*arr[p])){
        //printf("%s is a number\n", arr[p]);
        val[iter3] = atoi(arr[p]);
        myPoint.weights[iter3] = val [iter3];
        iter3++;
      }
  }



  printf("%s %s\n",  myPoint.items[0], myPoint.items[1]);

}


int main ()
{



    char *str[9];
    str[0] = "a = 2.b, 1.d, 3.d; 4.o; milk cheese";
    str[1] = "b = 2.a, 1.e, 2.c; water juice drinks";
    str[2] = "c = 2.b, 1.f; chips snacks";
    str[3] = "d = 1.a, 1.g; bread cereal pasta";
    str[4] = "e = 1.h, 1.b; meat chicken fish";
    str[5] = "f = 1.i, 1.c; oils sauces condiments";
    str[6] = "g = 1.j, 1.d; soup canned_goods";
    str[7] = "h = 1.k, 1.e; produce";
    str[8] = "i = 1.l, 1.f; beer";

    //char str[] = "a = 2.b, 1.d, 3.d; 4.o; milk cheese";

    int i;
    for (i=0; i<9; i++){
        makeStruct(*str);

    }

  return 0;
}

所以你可以看到，我正在嘗試接受str[0] ，輸出我正在打印的語句，然后使用循環重復該過程以傳入str[1] ， str[2], str[3],等等等等等等。

那么現在，如何正確初始化包含多個字符串的數組，然后將這些字符串傳遞給我的makeStruct函數？

Answer 1

在原始代碼中執行此操作時：

char str[] = "a = 2.b, 1.d, 3.d; 4.o; milk cheese";

您正在創建一個char數組並使用給定字符串常量的內容對其進行初始化。 這很好，因為即使無法更改字符串文字， str只包含該字符串文字中的內容的副本。

但是當你這樣做時：

char *str[9];
str[0] = "a = 2.b, 1.d, 3.d; 4.o; milk cheese";
str[1] = "b = 2.a, 1.e, 2.c; water juice drinks";
...

您正在創建一個指針數組，並為每個指針指定字符串文字的地址 。 因此，當您將*str傳遞給函數時，它會嘗試通過strtok函數修改字符串文字，這是不允許的。

您應該創建一個使用字符串常量初始化的二維char數組：

char str[9][50] = {
    "a = 2.b, 1.d, 3.d; 4.o; milk cheese",
    "b = 2.a, 1.e, 2.c; water juice drinks",
    "c = 2.b, 1.f; chips snacks",
    "d = 1.a, 1.g; bread cereal pasta",
    "e = 1.h, 1.b; meat chicken fish",
    "f = 1.i, 1.c; oils sauces condiments",
    "g = 1.j, 1.d; soup canned_goods",
    "h = 1.k, 1.e; produce",
    "i = 1.l, 1.f; beer"
};

此外，您的循環總是在數組的第一個元素中發送：

for (i=0; i<9; i++){
    makeStruct(*str);
}

索引數組以傳遞連續的元素：

for (i=0; i<9; i++){
    makeStruct(str[i]);
}

Answer 2

嘗試

 void makeStruct(char* str[],int number_of_strings){
       ...
    }

然后通過訪問每個字符串

 char * a = str[i];

我的范圍從0到number_of_strings-1