通過上面的例子讀者可能還未發(fā)現(xiàn)多態(tài)的用途，不過確實也是，多態(tài)在小項目中鮮有有用武之地。

接下來的例子中，我們假設(shè)你正在玩一款軍事游戲，敵人突然發(fā)動了地面戰(zhàn)爭，于是你命令陸軍、空軍及其所有現(xiàn)役裝備進入作戰(zhàn)狀態(tài)。具體的代碼如下所示：

#include <iostream> using namespace std; //軍隊 class Troops{ public:virtual void fight(){ cout<<"Strike back!"<<endl; } }; //陸軍 class Army: public Troops{ public:void fight(){ cout<<"--Army is fighting!"<<endl; } }; //99A主戰(zhàn)坦克 class _99A: public Army{ public:void fight(){ cout<<"----99A(Tank) is fighting!"<<endl; } }; //武直10武裝直升機 class WZ_10: public Army{ public:void fight(){ cout<<"----WZ-10(Helicopter) is fighting!"<<endl; } }; //長劍10巡航導(dǎo)彈 class CJ_10: public Army{ public:void fight(){ cout<<"----CJ-10(Missile) is fighting!"<<endl; } }; //空軍 class AirForce: public Troops{ public:void fight(){ cout<<"--AirForce is fighting!"<<endl; } }; //J-20隱形殲擊機 class J_20: public AirForce{ public:void fight(){ cout<<"----J-20(Fighter Plane) is fighting!"<<endl; } }; //CH5無人機 class CH_5: public AirForce{ public:void fight(){ cout<<"----CH-5(UAV) is fighting!"<<endl; } }; //轟6K轟炸機 class H_6K: public AirForce{ public:void fight(){ cout<<"----H-6K(Bomber) is fighting!"<<endl; } }; int main(){Troops *p = new Troops;p ->fight();//陸軍p = new Army;p ->fight();p = new _99A;p -> fight();p = new WZ_10;p -> fight();p = new CJ_10;p -> fight();//空軍p = new AirForce;p -> fight();p = new J_20;p -> fight();p = new CH_5;p -> fight();p = new H_6K;p -> fight();return 0; } Strike back! --Army is fighting! ----99A(Tank) is fighting! ----WZ-10(Helicopter) is fighting! ----CJ-10(Missile) is fighting! --AirForce is fighting! ----J-20(Fighter Plane) is fighting! ----CH-5(UAV) is fighting! ----H-6K(Bomber) is fighting!

這個例子中的派生類比較多，如果不使用多態(tài)，那么就需要定義多個指針變量，很容易造成混亂；而有了多態(tài)，只需要一個指針變量 p 就可以調(diào)用所有派生類的虛函數(shù)。

從這個例子中也可以發(fā)現(xiàn)，對于具有復(fù)雜繼承關(guān)系的大中型程序，多態(tài)可以增加其靈活性，讓代碼更具有表現(xiàn)力。

《新程序員》：云原生和全面數(shù)字化實踐50位技術(shù)專家共同創(chuàng)作，文字、視頻、音頻交互閱讀

總結(jié)

以上是生活随笔為你收集整理的多态的用途的全部內(nèi)容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網(wǎng)站內(nèi)容還不錯，歡迎將生活随笔推薦給好友。