Common array errors

1. studentNum <= grades.length
   if studentNum = grades.length, then the array element with index
   grades[studentNum] causes an array out of bounds exception.
   Since the indices start at 0, this means they only go to the arrays length - 1.

2. studentNum may not have been initialized

3. grades(studentNum)
   java would think is a call to a method grades with a parameter studentNum.
   It should be looking at indices in an array...arrays use square brackets. SO

   grades[studentNum] = "A";

   is the correct syntax for putting the string value of "A" into the array grades at location studentNum.

   If this were the instantiation of the array grades
   String [] grades = new String[4];
   then when this loop is done,

   public void defaultFillGrade(String [] grades){ for (studentNum = 0; studentNum < grades.length; studentNum++) grades[studentNum] = "A"; }

ARRAY grades:	A	A	A	A
INDICES	0	1	2	3