c - If(int IDnumvariable == structname[counter].IDnumber) 不起作用

Question

已关闭。此问题需要 debugging details 。目前不接受答案。

---

编辑问题以包含 desired behavior, a specific problem or error, and the shortest code necessary to reproduce the problem 。这将有助于其他人回答问题。

已关闭 7 年前。

Improve this question

我陷入了图书借阅功能的困境，问题是当我必须将用户输入的教师 ID 与教师文件中的现有 ID 进行比较时。我的 id 数据类型都是整数，所以我使用:

    void tborrow() //2.1
{
    int bksb=0;
    int tbid2 =0;   
    struct books book[50];
    struct teachers teach[50];
    int x=0;
    int c=0;
    int i=0;
    int tid=0;
    int tid2=0;
    int tbid=0;
    FILE *teacherp;
    FILE *bkbp;


        teacherp= fopen("TeacherFile.txt", "r+");

    if(teacherp!=NULL)  //Checks if Teacher File was created successfully
    {

        printf("Teacher File Successfully Opened\n\n\n");
        printf("Enter Teacher's ID# :");
        scanf("%d",&tid);


        while(1) // Loop till end of file
        {
            fflush(stdin);////flushes buffer 
            fscanf(teacherp,"%s %d %s %s %d ",teach[i].Teachname,&teach[i].IDnum,teach[i].contactnum,teach[i].Faculty,&teach[i].bksborrowed);
            tid2= tid2 + teach[i].IDnum;
            if (tid == tid2)
            {
                    system("cls");
                    printf("Teacher ID Confirmed\n\n");

                    printf("\n\n----Teacher Information-----");  //check if correctly entered
                    printf("\nName: %s ", teach[i].Teachname);
                    printf("\nID #: %d " ,teach[i].IDnum);
                    printf("\nContact #: %s ", teach[i].contactnum);
                    printf("\nFaculty: %s " ,teach[i].Faculty);
                    printf("\nBooks Borrowed: %d " ,teach[i].bksborrowed);
                    printf("\n-----------------------------\n");
                    printf("\nIs your account? 1-Yes  0=No : ");
                    scanf("%d",&c);
                    fflush(stdin);//flushes buffer after scanf

                    if (c==1)//if yes find and borrow book
                            {
                                bksb = bksb+teach[i].bksborrowed;
                            if (bksb < 2)// if teacher has less than 2 books borrowed
                            {
                                    printf("\nThis account currently has %d books borrowed",teach[i].bksborrowed);

                                    bkbp = fopen("BookFile.txt","r+");

                                    if(bkbp!=NULL)  //Checks if Book File was created successfully if yes search for book and borrow
                                    {

                                        printf("Enter Book ISBN # :");
                                        scanf("%d",&tbid);
                                        while(1)
                                        {

                                            fscanf(bkbp,"%s %s %d %d %s %d %d-%d-%d %d-%d-%d ",book[x].Title, book[x].Author, &book[x].Accessionnum, &book[x].ISBN, book[x].Available, &book[x].bid, &book[x].bdate->m, &book[x].bdate->d, &book[x].bdate->y, &book[x].rdate->m, &book[x].rdate->d, &book[x].rdate->y);
                                            tbid2 = tbid2 + book[x].ISBN;
                                            if (tbid == tbid2)
                                            {
                                                printf("\n\n-------Book Information-------");  //check if correct book found
                                                printf("\nTitle: %s", book[x].Title);
                                                printf("\nAuthor: %s" ,book[x].Author);
                                                printf("\nAccession#: %d" ,book[x].Accessionnum);
                                                printf("\nISBN#: %d", book[x].ISBN);
                                                printf("\nAvailability(Y-N): %s" ,book[x].Available);
                                                printf("\nBorrowers ID#: %d ",book[x].bid);
                                                printf("\nBorrow Date: %d-%d-%d ",book[x].bdate->m,book[x].bdate->d,book[x].bdate->y);
                                                printf("\nReturn Date: %d-%d-%d ",book[x].rdate->m,book[x].rdate->d,book[x].rdate->y);  //Prints user entry to screen for confirmation
                                                printf("\n------------------------------\n");
                                                printf("\nIs this the book you are looking for? 1-Yes  0=No : ");
                                                scanf("%d",&c);
                                                fflush(stdin);//flushes buffer after scanf
                                                if (c==1)//if yes print into file
                                                {
                                                    book[x].bid=tid2;
                                                    bksb++;
                                                    teach[i].bksborrowed=bksb;
                                                    printf("\n Book %s has been borrowed by %s %d",book[x].Title,teach[i].Teachname,teach[i].IDnum);
                                                    fclose(bkbp);
                                                    printf("\n\nReturning to previous account");
                                                    _getch();
                                                    break;
                                                    TeacherAcc();
                                                }
                                                /*else
                                                    {
                                                    fclose(bkbp);
                                                    system("cls");
                                                    printf("\nStarting over book borrowing!");
                                                    break;
                                                    tborrow();
                                                     }*/


                                            }
                                            else
                                            //if we encountered the end of the file on the last attempt
                                            //to read data then break out of the read loop
                                            if( feof(bkbp) ) //If end of file is reached break out of loop
                                            {
                                                break;
                                            }

                                            ++x;
                                        }




                                    }else // if book file failed to open
                                        {
                                        printf("Error!, Restarting Teacher Book Borrowing System. Press Enter to continue");
                                        getchar();
                                        tborrow();
                                        }
                            }else if (teacher[i].bksborrowed == 2) // if teacher has already borrowed 2 books
                                            {
                                                printf("\nThis account already has %d books borrowed",teach[i].bksborrowed);
                                                printf("\nGoing back to previous menu");
                                                _getch();
                                                system("cls");
                                                TeacherAcc();
                                            }

                            }
                            else if (c==0)  //runs the Teacher borrow function if wrong account
                                {
                                    system("cls");
                                    printf("\nRe-Enter Teacher ID!");
                                    tborrow();
                                }




            }else // else if teacher id not found
                    {
                        printf("\nID %d not found, Please re-enter a valid ID \n Press enter to try again",tid);
                        _getch();
                        system("cls");
                        tborrow();
                    }
        if( feof(teacherp) ) //If end of file is reached break out of loop
        {
            break;
        }else

        i++;
        }//end of continuous loop

        fclose(teacherp); //close the file when done
    }   //if file created successfully
    else    //Teacher file failed to load, restarts function to correctly open Teacher
        {
            printf("Error!, Restarting Teacher System. Press Enter to continue");
            getchar();
            system("cls");
        }
    printf("\n\nReturning to previous menu, Press Enter to continue \n");
    fflush(stdin);//flushes buffer so getchar works properly
    getchar();
    system("cls");
    TeacherAcc();
}//borrow function end

但它没有正确比较或存储我从文件中读取的 id，并且该文件存在并且具有用于测试的存储 id

附件是我老师借用函数的代码块任何帮助将不胜感激

我正在考虑将 id 数据类型设为 char 并使用 strcmp(userentered,struct[count].idnum)

Answer 1

(形成评论)删除 tid2= tid2 +each[i].IDnum;。

是的，您可以使用if (tid ==each[i].IDnum)

但是，看看 tborrow 中的 while(1) 循环正在做什么:

while(1)
   read a teacher from the file
   is the teacher the right one?
      yes - do something
      no  - print an error and recursively call tborrow again.

想一想，如果您在纸上的列表中手动寻找老师，您会如何做 - 您会查看列表中的第一位老师，然后放弃并重新开始(如果不是合适的老师) ？