Question

Suppose r contains a reference to a new rectangle(5, 10, 20, 30). which of the fol­lowing assignments is legal? (look inside the api documentation to check which interfaces the rectangle class implements.)
a. rectangle a = r;
e. measurable e = r;
b. shape b = r; f. serializable f = r;
c. string c = r; g. object g = r;
d. actionlistener d = r;

Answer 1

The legal in this following assignments is no other than e. measurable e = r. It is measurable because r contains a reference to a new rectangle(5, 10, 20, 30). So the interfaces the rectangle class implements is measurable, we really can measure it by solving the rectangle sides.