and 5. In for loops, you donâ??t have to start at 0 or 1, and you also donâ??t have to increment the number. Hereâ??s how to count upward between 10 and 20:
for (var i = 11; i < 20; i++) { document.writeln(i + "<br />"); }
And hereâ??s how to reverse the count:
for (var i = 19; i > 10; i--) { document.writeln(i + "<br />"); }