How do I get the area of every closed polyline in an AutoCAD drawing?

What cadssistant does

1. Selects the closed LWPOLYLINEs on the layer: (0 . "LWPOLYLINE") with the closed bit of group 70 tested through a (-4 . "&") filter.
2. Reads each area with vlax-curve-getArea in one AutoLISP pass and converts it with the factor the drawing's units imply (1 unit = 1 mm gives ÷ 1 000 000), stating the factor in the reply.
3. Replies with a table of handle and area, plus the total.

The same task in AutoLISP

(progn
  (vl-load-com)
  (setq ss (ssget "_X" '((0 . "LWPOLYLINE") (8 . "A-AREA") (-4 . "&") (70 . 1)))
        i 0 rows nil)
  (if ss
    (repeat (sslength ss)
      (setq e (ssname ss i) i (1+ i))
      (setq rows (cons (list (cdr (assoc 5 (entget e))) (/ (vlax-curve-getArea e) 1e6)) rows))))
  rows)

Handle and area in m² for a drawing in millimetres. Use 1e4 for centimetres, or drop the division for metres.

Good to know

• An outline drawn as separate lines isn't a closed polyline. Say "join the lines on A-AREA into polylines first" and it runs PEDIT with Join before measuring.

More in count and measure

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• How do I count blocks by name in AutoCAD?
• How do I get the total length of all lines and polylines on a layer in AutoCAD?
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