c - C实践中二维字符数组的逻辑

Question

typedef struct{

    int moviesRented;
    char title[20][20];

} Movie;

typedef struct{
    int accNumber;
    char name[20];
    Movie movie_rental;
} Customer;


int main(){
    int i;
    int j;
    int customerRecords;
    Customer *pCustomer;


    printf("Enter amount of customer records to be kept: ");
    scanf("%d", &customerRecords);

    pCustomer = malloc(customerRecords * sizeof(Customer));

//这将开始询问与客户相关的输入

    for(i = 0; i < customerRecords; ++i){
        printf("Enter account number, name, and movies rented: \n");
        scanf("%d\n %s\n %d", &(pCustomer + i)->accNumber, &(pCustomer +i)->name, &(pCustomer + i)->movie_rental.moviesRented);

//下面的for循环根据已租借的电影数量要求多个电影标题

        for( j = 0; j < (pCustomer+i)->movie_rental.moviesRented; ++j){ 

        //asking for input of movie titles and trying to add into string array

            printf("Enter Movie titles: \n");
            scanf("%s", &(pCustomer+i)->movie_rental.title[j]);

        }

    }
        printf("Displaying information: \n");

    for(i = 0; i < customerRecords; ++i){
        printf("Name: %s\nAcc. Number: %d\nNo. Movies Rented: %d\n",(pCustomer+i)->name, (pCustomer+i)->accNumber, (pCustomer+i)->movie_rental.moviesRented);

//下面的for循环显示不正确。只显示第一次迭代中的最后一个条目

            for(j = 0; j < (pCustomer+i)->movie_rental.moviesRented; j++){ 
               printf("Movies rented: %s\n", (pCustomer+i)->movie_rental.title[j]);
            }
        return 0;
    }

Answer 1

问题在于您在 movie_rental_title 中的索引。

scanf("%s", &(ptr+i)->movie_rental.title[i]);

无论每个客户有多少部电影，此行每次都会覆盖电影名称。你想要的是 movie_rental.title[j] 因为 i 在循环期间永远不会改变。

在显示中您还想将 movie_rental.title[i] 更改为 movie_rental.title[j]

同时尽量使变量名尽可能具有描述性，这样您就可以避免像这样难以检测的错误。