Hello, I’m having issues with += operator to calculate the average of an array of type class. This is occurring in my Calculate_Average function. For some reason, it does not agree with the object I’ve created. I was wondering if someone could please point me in the right direction as to what mistake I’m making. The code is to populate the matrices and calculate the average of entries of the grades object matrix from class student (gr). Thanks in advance :

```
class Student
{
float [] id;
float [] gr;
}
void PopulateArray (Student [] ident, Student [] grad)
{
for(int i = 0; i < ident.length;i++)
{
ident[i].id = ident[i+1].id;
}
for(int j = 0; j < grad.length;j++)
{
grad[j].gr = grad[(int(random(40,100)))].gr;
}
}
Float Calculate_Average (Student [] grades)
{
float average = 0;
for (int i = 0; i < grades.length; i ++)
{
average += grades[i];
}
print(average);
return average;
}
void setup ()
{
Student [] grades = new Student [10];
Student [] ID = new Student [10];
PopulateArray(ID, grades);
Calculate_Average(grades);
println(grades.gr);
}
```