(let ((ref2 (list '())))
(push (progn (princ "1") 'ref-1)
(car (progn (princ "2") ref2))))
|> 12
⇒ (REF1)
(let (x)
(push (setq x (list 'a))
(car (setq x (list 'b))))
x)
⇒ (((A) . B))
push first evaluates (setq x (list 'a)) ⇒ (a)
,
then evaluates (setq x (list 'b)) ⇒ (b)
,
then modifies the car of this latest value to be ((a) . b)
.