Advance function pointer problem.

[Siaw Ys]

First please view the below code...

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

    struct Date 
    {
        int year, month, day;
    };

    struct Student
    {
        char ID[30];
        char name[30];
        struct Date date_of_birth;

    } StudentRec;

    void GetStudentRec(StudentRec *st);
    void GetDOB(Date *dt);

    int main(void)
    {



    }

    void GetStudentRec(StudentRec *st);
    {
        int wish, i;

        printf("How many wish: "):
        scanf("%d", &wish);

        for(i=0; i<wish; i++)
        {
            printf("Please input student name: ");
            scanf("%[^\n], &(*st[i]).ID);

        }


        
        
    }

I have try my best to solve the error but I can't so please help...The error below...

error C2143: syntax error : missing ')' before '*'

[laserlight]

Looks like you forgot to use typedef. Without typedef, you should refer to struct Date as struct Date, not as Date. Likewise, StudentRec is an object of type struct Student, not an alias for struct Student.

[MK27]

You have a colon instead of a semi-colon at the end of line 32.

[Siaw Ys]

Please view below code...

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

    struct Date {

        int year, month, day;
    };

    typedef struct Student {

        char ID[30];
        char name[30];
        struct Date date_of_birth[30];

    } StudentRec;

    
    void GetStudentRec(StudentRec *st);


    int main(void)
    {

        StudentRec stud;

        GetStudentRec(&stud);

        




    }

    void GetStudentRec(StudentRec *st)
    {
        int wish, i;

        printf("How many wish: ");
        scanf("%d", &wish);

        for(i=0; i<wish; i++)
        {
            fflush(stdin);

            printf("\nPlease input student ID: ");
            scanf("%[^\n]", &st->ID[i]);

            fflush(stdin);

            printf("\nPlease input student name: ");
            scanf("%[^\n]", &st->name[i]);

            fflush(stdin);

            printf("\nPlease input student day: ");
            scanf("%d", &st->date_of_birth[i].day);

            fflush(stdin);

            printf("\nPlease input student month: ");
            scanf("%d", &st->date_of_birth[i].month);

            fflush(stdin);

            printf("\nPlease input student year: ");
            scanf("%d", &st->date_of_birth[i].year);

            fflush(stdin);

        }

        for(i=0; i<wish; i++)
        {
            printf("\nID: %s", st.ID[i]);
            printf("\nName: %s", st.name[i]);
            printf("\nDay: %d", st.date_of_birth[i].day);
            printf("\nMonth: %d", st.date_of_birth[i].month);
            printf("\nYear: %d", st.date_of_birth[i].year);
        }
        
        
    }

How can I print all the student info after the user input? I try to print it but...

[CommonTater]

1) You need st->ID (etc) not st.ID ... This because st is a pointer.

2) don't use fflush(stdin)... You don't flush your fawcets do?

3) main is defined correctly as... int main (void).. but at the end you don't return anything: add ... return 0; ... at the closing brace.

4) you have defined your struct with arrays of 30 ... I hope you don't think this represents 30 students....
The way to represent 30 students is like this...

    struct Date {

        int year, month, day;
    };

    typedef struct Student {

        char ID[10];
        char name[30];
        struct Date date_of_birth;

    } StudentRec;

    
    void GetStudentRec(StudentRec *st);


    int main(void)
    {

        StudentRec stud[30];

In which case your array is an array of structs... not a struct of arrays.
You would access them like this... stud[i].ID ...

[Siaw Ys]

Very thanks...now I able to print all values without problem but I need some help in figure some function prototypes which I don't understand. So please first view the image below...



The image above show my question...and I don't understand what the purpose of void GetDOB(Date *). This is because I already ask user input all the students info in void GetStudentRec() but now this question require me to create another prototypes for DOB?

Below is my newest codes...

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

    struct Date {

        int year, month, day;

    };

    typedef struct {

        char ID[30];
        char name[30];
        struct Date date_of_birth;

    } StudentRec[30];
    
    void GetStudentRec(StudentRec *st);


    int main(void)
    {
        StudentRec stud;

        GetStudentRec(&stud);

    }

    void GetStudentRec(StudentRec *st)
    {

        int stud, i;

        printf("How many students: ");
        scanf("%d", &stud);

        for(i=0; i<stud; i++)
        {
            

            printf("\nPlease input student ID: ");
            scanf("%[^\n]", &st[i]->ID);

            

            printf("\nPlease input student name: ");
            scanf("%[^\n]", &st[i]->name);

            

            printf("\nPlease input student day: ");
            scanf("%d", &st[i]->date_of_birth.day);

            

            printf("\nPlease input student month: ");
            scanf("%d", &st[i]->date_of_birth.month);

            

            printf("\nPlease input student year: ");
            scanf("%d", &st[i]->date_of_birth.year);

            

        }

        for(i=0; i<stud; i++)
        {
            printf("\nID: %s", st[i]->ID);
            printf("\nName: %s", st[i]->name);
            printf("\nDay: %d", st[i]->date_of_birth.day);
            printf("\nMonth: %d", st[i]->date_of_birth.month);
            printf("\nYear: %d", st[i]->date_of_birth.year);
            printf("\n");
        }
        
        
    }

[CommonTater]

I would do it the way you are... However the assignment seems to want you to call GetDOB from within GetStudentRec... This isn't especially difficult, but it is rather pointless.

You can just create a separate function above GetStudentRec, but below main to get the dates and call it from GetStudentRec...

The only thing I would change in your existing code is that line 17 should not specify the array size... that should be done at line 24.

[Siaw Ys]

First please view the below question...

Write a function called elapsedTime with two parameters, the start time and the end time. Each parameter is a structure with three fields showing the hours, minutes, and seconds of a specific time. The function is to return a time structure containing the time elapsed between the two parameters. You must handle the situation when the start time is in the previous day.

__________________________________________________ _____________

My coding so far...

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

    struct time
    {
        int hour;
        int min;
        int sec;

    } start_time, end_time;

    void main ()
    {
        
    }
    
    int elapsedTime(struct start_time*s, struct end_time*e) 
    {

        
    }

My problem is I don't know how should I continue...I mean what means by return a time structure containing the time elapsed between the two parameters? And also how I can handle the situation when the start time is in the previous day? I just hope that at least someone can give me some hints to helps me continue...

[CommonTater]

This should probably be in a new thread... new problem, new thread.
=====
Oh my... no functional code at all and already you've got problems...

DO NOT use void main() ... the correct skeleton for a C program is...

int main (void)
  {
     // your stuff

     return 0; 
}

Your function declaration for Elapsed time is wrong...

int elapsedTime( struct start_time *s, struct end_time *e)
 { 
...

Best hint I can give you is... THINK about the problem... don't ask us to do your thinking for you.