Answer 1

Yes of course.
You can add the 10th element without the other 9 arrays.

var courses = new Array();
courses[9] = "JS";

Answer 2

what course?

Answer 3

What you mean ;
to select or to add

Answer 4

Give example of code.

Answer 5

just wait.

Answer 6

Yes.

Answer 7

James Clark I. Vinarao that was what I was saying

Answer 8

Sigauq
Yeah of course it is possible
But the other elemets may contain either zero or any garbage values