在谷歌搜索了一段时间,但似乎无法找到明确的答案。
如何在以下示例中调用unscramble()方法?
感谢。 :^)
class Food {
public:
Food(string _t):type(_t);
virtual void eat() = 0;
private:
string type;
}
class Fruit : public Food {
public:
Fruit(string _t):Food(_t) {
virtual void eat() { // Yummy.. }
}
class Egg : public Food {
public:
Egg(string _t):Food(_t)};
virtual void eat() { // Delicious! };
void unscramble();
}
int main() {
Food *ptr[2];
ptr[0] = new Fruit("Apple");
ptr[1] = new Egg("Brown");
// Now, I want to call the unscramble() method on Egg.
// Note that this method is unique to the Egg class.
ptr[1]->unscramble();
// ERROR: No member "unscramble" in Food
cout << "\n\n";
return 0;
}
答案 0 :(得分:6)
如果你确定它是鸡蛋:
static_cast<Egg*>(ptr[1])->unscramble();
如果你不知道它是否是鸡蛋:
auto egg = dynamic_cast<Egg*>(ptr[1]);
if (egg != nullptr)
egg->unscramble();
答案 1 :(得分:1)
您可以通过以下方式使用dynamic_cast
:
auto e = dynamic_cast<Egg*>(ptr[1]);
if(e) e->unscramble();