C/code/用静态数据成员和静态函数统计猫的数量——11-01.cpp

#include <iostream>

// Cat class definition
class Cat {
public:
    static int HowManyCats; // Static data member to keep track of the number of Cat objects

    // Constructor that takes age as a parameter
    Cat(int age) : age(age) {
        ++HowManyCats;
    }

    // Destructor
    ~Cat() {
        std::cout << "destructing of the cat!" << std::endl;
        --HowManyCats;
    }

    // Static member function to get the number of Cat objects
    static int GetHowMany() {
        return HowManyCats;
    }

private:
    int age; // Age of the cat
};

int Cat::HowManyCats = 0; // Initialize static data member

// Function to create an array of 5 Cat objects with ages 1, 2, 3, 4, 5
void creating() {
    std::cout << "before the Cat array is created, the number of the cat is:" << Cat::GetHowMany() << std::endl;

    Cat* cats[5]; // Array of pointers to Cat objects

    // Create 5 Cat objects with ages 1, 2, 3, 4, 5
    for (int i = 0; i < 5; ++i) {
        cats[i] = new Cat(i + 1);
    }

    std::cout << "after the Cat array is created, the number of the cat is:" << Cat::GetHowMany() << std::endl;

    // Delete the 5 Cat objects to free memory and reduce the count
    for (int i = 0; i < 5; ++i) {
        delete cats[i];
    }
}

int main() {
    std::cout << "before the function, the number of the cat is:" << Cat::GetHowMany() << std::endl;

    creating();

    std::cout << "after the function, the number of the cat is:" << Cat::GetHowMany() << std::endl;

    return 0;
}