我更喜欢使用局部变量而不是多次调用同一个方法。/**Ipreferthis*/Vehiclevehicle=person.getVehicle()if(vehicleinstanceofCar){Carcar=(Car)vehicle;car.openSunroof();}elseif(vehicleinstanceofBike){Bikebike=(Bike)vehicle;bike.foldKickstand();}/**Ratherthanthis*/if(person.getVehicle()instanceofCar){Carcar=(Car)person.getVehicl