size - Returns the size of an array/string.
array size -> n array
string size -> n string
[1 2] size -> 2 [1 2]
(hello) size -> 5 (hello)
Returns the number of elements (similar to length) of
an object and additionally the object itself.
docu by Sirko Straube
/var/www/debian/nest/nest-simulator-2.20.0/sli/slidata.cc