Accessing Struct Layers Using Reference Operator - c

Question

How can I cycle through the array using a for loop and the reference operator?
for (i = 0; i < university->size; i++)
{
if (university->arr->MarkA <= 100)
{
sum += university->arr->MarkA;
count++;
}
Where should I insert the i?
These are the structures:
typedef struct Student
{
char *name;
long ID;
int MarkA, MarkB, HW;
}stud;
typedef struct University
{
stud *arr;
int size;
}Uni;
I used a function to create a University array
void build_Uni(FILE* in, Uni* university)
{
int i = 0;
stud temp;
char Name[100];
while (!feof(in))
{
fscanf(in, "%s%li%d%d%d", Name, &temp.ID, &temp.MarkA, &temp.MarkB, &temp.HW);
i++;
}
university->size = i;
rewind(in);
university->arr = (stud*)malloc(university->size * sizeof(stud));
if (university->arr == NULL) Get_Lost("Memory allocation failed!");
else for (i = 0; i < university->size; i++)
fill_Uni(in, university->arr + i);
}
void fill_Uni(FILE* in, stud* student)
{
char Name[100];
fscanf(in, "%s%li%d%d%d", Name, &student->ID, &student->MarkA, &student->MarkB, &student->HW);
student->name = (char*)malloc((strlen(Name) + 1) * sizeof(char));
if (student->name == NULL) Get_Lost("Error allocatig memory");
strcpy(student->name, Name);
}
In the main function I called the above functions to work on this structure
Uni university;

Answer 1

How can I cycle through the array using a for loop and the reference
operator?
I think you mean the dereference operator -> but referencing and dereferencing will have nothing to do with cycling through the array; that's what your for-loop is for.
Where should I insert the i?
This:
for (i = 0; i < university->size; i++)
{
if (university->arr->MarkA <= 100)
{
sum += university->arr->MarkA;
count++;
}
}
Should be this:
for (i = 0; i < university->size; i++)
{
if (university->arr[i].MarkA <= 100)
{
sum += university->arr[i].MarkA;
count++;
}
}

Answer 2

Concerning your original question, you should access it as follows:
University university;
...
for (i = 0; i < university.size; i++) {
if (university.arr[i].MarkA <= 100)
{
sum += university.arr[i].MarkA;
count++;
}
...
}
If university is of type University*, however, the code changes a little bit, since you then have to use operator -> to access the university-members:
for (i = 0; i < university->size; i++) {
if (university->arr[i].MarkA <= 100)
{
sum += university->arr[i].MarkA;
count++;
}
...
}