Question

以下是TEXT FILE的输入：

19 BISON-BURGER 10 15.000000
10 BRAISED-COD 5 17.000000
23 MOJITO 8 11.000000
3 IRISH-COFEE 6 2.300000
7 LAMB-SHOULDER 8 23.000000

输入密钥后输出来自编译器：

10 BRAISED-COD 5 17.000000
3 IRISH-COFEE 6 2.300000
7 LAMB-SHOULDER 8 23.000000

为什么编译器会跳过某些行？我需要做出哪些改变？

请帮忙。非常感谢。

以下是完整代码：

#include <stdio.h>
#include <stdlib.h>
#include <windows.h>
#include <ctype.h>

struct product
{
    int quantity, reorder, i, id;
    char name[20];
    float price;
};

    int main()
    {
    FILE * fp;

    int i=0;
    struct product a;
    system("cls");

    char checker;

        do
        {
        fp = fopen("addproduct.txt","a+t");
        system("cls");

        printf("Enter product ID : ");
        scanf(" %d", &a.id);

        printf("Enter product name : ");
        scanf(" %s", a.name);

        printf("Enter product quantity : ");
        scanf(" %d", &a.quantity);

        printf("Enter product price : ");
        scanf(" %f", &a.price);


        fprintf(fp, "%d %s %d %f\n\n", a.id, a.name, a.quantity, a.price);
        printf("Record saved!\n\n");

        fclose(fp);

        printf("Do you want to enter new product? Y / N : ");

        scanf(" %c", &checker);
        checker = toupper(checker);

        i++;

        system("cls");
        }

        while(checker=='Y');



        if(checker == 'N')
        {
        fp = fopen("addproduct.txt","r");

        while(fscanf(fp, "%d %s %d %f", &a.id, a.name, &a.quantity, &a.price)==4)
            {
        fscanf(fp, "%d %s %d %f", &a.id, a.name, &a.quantity, &a.price);
        printf("%d %s %d %f\n\n", a.id, a.name, a.quantity, a.price);
            }

        fclose(fp);

        }


        return(0);
}

Answer 1

在输出循环的每次迭代中，您正在从文件中读取两行。摆脱额外的scanf：

    while(fscanf(fp, "%d %s %d %f", &a.id, a.name, &a.quantity, &a.price)==4)
    {
        printf("%d %s %d %f\n\n", a.id, a.name, a.quantity, a.price);
    }

Answer 2

您每次通过fscanf()循环调用while两次。首先是while条件，然后是循环体。您只打印第二个读取的变量，因此忽略第一个fscanf()读取的行。摆脱第二个fscanf()。

while(fscanf(fp, "%d %s %d %f", &a.id, a.name, &a.quantity, &a.price)==4)
{
    printf("%d %s %d %f\n\n", a.id, a.name, a.quantity, a.price);
}

C编程TEXT FILE没有读取整行

2 个答案: