array.size() and array.NumElements()

[innominabile]

I think could be a fast mode (1 escript command) to count in an array the valid elements really used and defined.

[MuadDib]

Straight off the POL Documentation site and Distro Documents:

http://poldoc.fem.tu-ilmenau.de/pol096/objref.php#Array

If you notice, .size() already exists.