User Input to Array of Structs C - arrays

Question

I am creating a program that gets user input and puts it into a struct called Student before returning back to a main menu. From the main menu you can add another student. This works but when I try to print all of the Students data that has been added to the array of structs it only prints the last Student that was added.
Here is the struct:
struct Student
{
char* firstName;
int age, cuid;
float GPA;
};
This is how I'm allocating space for the array in main:
struct Student* studentArray = malloc(*recordMaxPtr * sizeof(struct Student));
Here are the functions that capture user input and print the array:
// Gets info and adds student to the array of structs
void addStudents(struct Student* s, int *numStudents)
{
// Allocate memory for the first name
char *firstName = (char*) malloc(25*sizeof(char));
// Gets the name of student
printf("What is the name of the student you'd like to add? ");
gets(s->firstName);
printf("\n"); // blank line
// Gets age of student
printf("How old is the student? ");
scanf("%d", &s->age);
printf("\n"); // blank line
// Gets CUID
printf("What is his / her CUID number? ");
scanf("%d", &s->cuid);
printf("\n"); // blank line
// Gets GPA
printf("What is the student's GPA? ");
scanf("%f", &s->GPA);
printf("\n"); // blank line
}
// Sorts the array and then lists all of the saved students
void printStudents(struct Student* s, int *numStudents)
{
//bsort();
for (int i = 0; i < *numStudents; i++)
{
printf("Student #%d\n", i + 1);
printf(" Student's Name: %s\n", s[i].firstName);
printf(" Age: %d\n", s[i].age);
printf(" CUID: %d\n", s[i].cuid);
printf(" GPA: %2f\n", s[i].GPA);
}
}
I thought about trying to use a for loop to gather all of the student's data that I need at once but this is a school project and I'm not allowed to do it that way. I've been trying to figure this out for a while and I've sort of hit a brick wall on what to do. My best guess is that data is getting overwritten every time you enter a new student to the array but I'm not sure how to fix that.

Answer 1

You allocated a memory for the first name, but didn't save that anywhere. You have to store the address to the structure.
// Allocate memory for the first name
char *firstName = (char*) malloc(25*sizeof(char));
s->firstName = firstName; // add this
Also here are some more things to do for better code:
Check if malloc() succeeded
Check if scanf() succeeded
Replace gets() with fgets() and removal of newline character (gets() has unavoidable risk of buffer overrun and removed from new C specification)
Remove the cast of result of malloc() (c - Do I cast the result of malloc? - Stack Overflow)