makeAnimalAction(dogAction)// TS Error at compilation, since we are trying to use `doDogThing()` to a `Cat` 這里作為實參的dogAction函數(shù)接受一個Dog類型的參數(shù),而makeAnimalAction的形參animalAction接受一個Dog的父類Animal類型的參數(shù),返回值都是void,那么按照正常的思路,這時應(yīng)該可以像上面協(xié)變的例子一...