Help me in developing my print function possible sort function

[rwise5]

I have been tasked with finishing the following C program. I need to develop the sort by birthday function and the print grade function. I have been working on the print function for the last week and it seems like everything I try doesn't work. I guess I am not understanding how to deal with structures. Please if someone could please help me out I would appreciate it.
Thank you.

 #include <stdio.h> 
 
#include <stdlib.h>
#include <string.h>
 
#define CLASS_SIZE 2
// maximum class size
 
struct test{
//declare structures
    float quiz1;
    float quiz2;
    float quiz3;
    float average;
    float GP;
};
 
struct date{
 
    int month;
    int day;
    int year;
};
 
struct student_data{
 
    char *last_name;
    int student_id;
    char grade;
};
 
 
void getGrade();
// function prototypes
void sort();
void swapd (struct date *s1, struct date *s2);
void swaps (struct student_data *s1, struct student_data *s2);
void swapt (struct test *s1, struct test *s2);
void prn_student_data();
 
struct student_data *students[CLASS_SIZE];
// structure declarations
struct date dob[CLASS_SIZE];
struct test tests[CLASS_SIZE];
 
 
int main(void)
// begin execution
{
    char temp[30];
    int i;
    float total=0;
 
    printf("\n\n This program will compute, sort by birthday, and
display a\n"    // user prompt
        " students average letter grade, quiz average? and grade
point obtained\n"
        " from 3 quizzes.\n\n");
 
    for(i=0; i<(CLASS_SIZE); i++)
//get student info
    {
        printf("\n\nEnter Student #%d's Last Name: ", i+1);
// user prompt
        scanf("%s", temp);
// user input
        students[i]=(struct student_data*)malloc(sizeof(struct
student_data));    // allocate memory for structure
        students[i]->last_name=(char*)malloc(strlen(temp));
// allocate memory for pointer last name in structure
        strcpy(students[i]->last_name, temp);
// copy from temp to struct member -last name
 
        printf("Enter Students ID Number: ");
//input student ID
        scanf("%d", &students[i]->student_id);
 
        printf("\nEnter Students Birthday (mm/dd/yyyy): \n");
//input birthday info
        printf(" ** Dont forget the forward slashes **: ");
        scanf("%d/%d/%d", &dob[i].month, &dob[i].day, &dob[i].year);
 
        printf("\n\nEnter quiz scores from 0 to 100\n");
        printf("\nEnter score obtained for quiz #1: ");
//input scores from quizzes
        scanf("%f", &tests[i].quiz1);
        printf("\nEnter score obtained for quiz #2: ");
        scanf("%f", &tests[i].quiz2);
        printf("\nEnter score obtained for quiz #3: ");
        scanf("%f", &tests[i].quiz3);
 
        total = (tests[i].quiz1)+(tests[i].quiz2)+(tests[i].quiz3);
//compute quiz total and average
        tests[i].average = (total/3);
        system("cls");
    }
 
    getGrade();
//call functions
    sort();
    prn_student_data();
 
    return 0;
}
 
 
void getGrade()
//grade conversion function
{
    int i;
 
    for(i=0; i<(CLASS_SIZE); i++)
 
    {
        if (tests[i].average >= 90.0)
            students[i]->grade = 'A', tests[i].GP = 4;
        else if (tests[i].average >= 80.0)
            students[i]->grade = 'B', tests[i].GP = 3;
        else if (tests[i].average >= 70.0)
            students[i]->grade = 'C', tests[i].GP = 2;
        else if (tests[i].average >= 60.0)
            students[i]->grade = 'D', tests[i].GP = 1;
        else
            students[i]->grade = 'F', tests[i].GP = 0;
    }
}
 

[D_C]

You do not pass any data to the print student function. Since the array that holds all student data is not static, your function has absolutely no idea of knowing where the data is to print. Either you could make the array of student structs static, pass the array (or each entry) by address (and as const too), or you could change the student struct to a class and make a print() method.

Also, in order sort by year, then month, then day, first sort by day, then by month, then by year. Make sure to use a stable sort.

[rwise5]

You do not pass any data to the print student function. Since the array that holds all student data is not static, your function has absolutely no idea of knowing where the data is to print. Either you could make the array of student structs static, pass the array (or each entry) by address (and as const too), or you could change the student struct to a class and make a print() method.

Also, in order sort by year, then month, then day, first sort by day, then by month, then by year. Make sure to use a stable sort.

Do you suggest that I use typedef to do this? I have been reviewing my notes and text book, but seems like I should really get involed with this program.
Thank you and take care.

[D_C]

Look at things in terms of priorities. Using typedef *should* simplify the declaration of data/structs. However, it is not necessary. All the data in your array of student structs is held somewhere in memory. You have to deliver your data to your print function somehow. That is absolutely necessary. There are several things you could do:

• declare the array as static
• pass by value each Student struct
• pass by address each Student struct
• pass by address the array of Student structs
• change Student from a struct to a class, and implement a print function