$(1)$ Given objl.setWeight$(5)$;

Does the method setweight have access to most of the instance vars of objl?

$(2)$ Given:

$(3)$ main$(...)($Valid or invalid$)$ boolean $flg=$ objl $$ obj$2$;

$(4)$ From#$2$:

main $(cdots)$ Valid $or$ invalid

$x.b_j=$ new $x(C)$;

$0bj*c=10$;

$x*c=20$;