在 C 中使用循环多次询问用户输入

Question

有了这个初学者的代码，只要输入不是“退出”，我就会尝试要求用户输入。 我的代码：

void createReport(){
    printf("Welcome to the report generator, type item's ID: ");
    char *userInput;
    int i=0;
    struct myStruct{
        char *name;
        int id;
        float sale;
    };
    struct myStruct *myStructArray[MAX_ITEMS];
    fgets(userInput,sizeof(int),stdin);
    while(strcmp(userInput,"quit")!=0) {
        userInput = malloc(sizeof(int));
        fgets(userInput,sizeof(int),stdin);
        searchA(userInput); //different function that changes global variable deletion
        printf("Added to the report, add more or type \'quit\' \n");
        strcpy(myStructArray[i]->name,inventoryItem[deletion].name);  //inventoryItem is global
        myStructArray[i]->id = atoi(input);
        myStructArray[i]->sale = inventoryItem[deletion].sale;
        i++;
        free(userInput);
    }
    for(int x=0;x<30;x++) printf(myStructArray[x]->name);  //never executed
}

此代码运行一次，要求用户输入，然后完成

有谁知道错误在哪里？ 感谢您的任何建议

Answer 1

在你做的while循环之前

fgets(userInput,sizeof(int),stdin);

那时您的变量userInput尚未设置。

编辑：

代码思路运行示例：

printf("Welcome to the report generator, type item's ID: ");
const int input_size = 6 * sizeof(char);
char *userInput = malloc(input_size);
int i = 0;
struct myStruct {
    char *name;
    int id;
    float sale;
};
struct myStruct *myStructArray[MAX_ITEMS];

fgets(userInput, input_size, stdin);
while (strcmp(userInput, "quit") != 0 && strcmp(userInput, "quit\n") != 0) 
{
    // do whatever you like with myStructArray[i], for example:
    myStructArray[i] = malloc(sizeof(struct myStruct));
    myStructArray[i]->name = malloc(sizeof(char));
    myStructArray[i]->name = "ab";
    myStructArray[i]->id = 7;
    myStructArray[i]->sale = 99.9F;
    printf("Added %s, %d, %f\n", myStructArray[i]->name, myStructArray[i]->id, myStructArray[i]->sale);

    //prepare for next iteration:
    printf("Added to the report, add more or type \'quit\' \n");
    for (int j = 0; j < input_size; ++j) // zeroing allocated data on the heap
        userInput[j] = 0;

    fgets(userInput, input_size, stdin);
    i++;
}
free(userInput);
for (int x = 0; x < i; x++) printf("%s,", myStructArray[x]->name);