Answer:
The missing part of the code is:
for (i = 0; i < courseGrades.length; ++i) {
System.out.print(courseGrades[i]+" "); }
System.out.println();
for (i = courseGrades.length-1; i >=0 ; --i) {
System.out.print(courseGrades[i]+" "); }
System.out.println();
Explanation:
This iterates through the array
for (i = 0; i < courseGrades.length; ++i) {
This prints each element of the array followed by a space
System.out.print(courseGrades[i]+" "); }
This prints a newline at the end of the loop
System.out.println();
This iterates through the array in reverse
for (i = courseGrades.length-1; i >=0 ; --i) {
This prints each element of the array (reversed) followed by a space
System.out.print(courseGrades[i]+" "); }
This prints a newline at the end of the loop
System.out.println();