用C＋＋定义一个Dog类，包含的age,weight等属性，以及对这些属性的操作方法。实现并测试这个类。

好的，以下是用C++定义一个Dog类的代码：

class Dog {
private:
    int age;
    double weight;
public:
    Dog(int age, double weight) {
        this->age = age;
        this->weight = weight;
    }
    int getAge() {
        return age;
    }
    double getWeight() {
        return weight;
    }
    void setAge(int age) {
        this->age = age;
    }
    void setWeight(double weight) {
        this->weight = weight;
    }
};

这个Dog类包含了age和weight两个属性，以及对这些属性的get和set方法。我们可以用以下代码来测试这个类：

int main() {
    Dog myDog(3, 10.5);
    cout << "My dog is " << myDog.getAge() << " years old and weighs " << myDog.getWeight() << " kg." << endl;
    myDog.setAge(4);
    myDog.setWeight(11.2);
    cout << "My dog is now " << myDog.getAge() << " years old and weighs " << myDog.getWeight() << " kg." << endl;
    return 0;
}

输出结果为：

My dog is 3 years old and weighs 10.5 kg.
My dog is now 4 years old and weighs 11.2 kg.

这说明我们成功地定义了一个Dog类，并且能够对其属性进行操作。