[已解决]C++静态方法

xiannv2b

getcount方法输出的永远是1，即使把return count改成return 0也一样
经测试，把getcount方法改成count属性，会得到想要的

#include <iostream>

class Dog
{
public:
    Dog();
    ~Dog();
    int getcount();

private:
    static int count;
};

int Dog::count = 0;

Dog::Dog()
{
    count += 1;
    std::cout << "add" << '\n';
}

Dog::~Dog()
{
    count -= 1;
    std::cout << "subtract" << '\n';
}

int Dog::getcount()
{
    return count;
}

int main()
{
    std::cout << Dog::getcount << '\n';
    Dog dog1; Dog dog2;
    std::cout << "count = " << Dog::getcount << '\n';
    {
        Dog dog3;
        std::cout << "count = " << Dog::getcount << '\n';
    }
    std::cout << "count = " << Dog::getcount << '\n';
}

结果

最佳答案

月排行榜 / 总排行榜

jhanker

2022-4-24 09:39:17

改成下面这样就可以了！

#include <iostream>

class Dog
{
public:
    Dog();
    ~Dog();
 static int getcount();//此处加上 static
private:
   static int count;
};

int Dog::count = 0;

Dog::Dog()
{
    count += 1;
    std::cout << "add" << '\n';
}

Dog::~Dog()
{
    count -= 1;
    std::cout << "subtract" << '\n';
}

int Dog::getcount()
{
    return count;
}

int main()
{
    std::cout <<"Dog::getcount"  << '\n';
   Dog dog1; Dog dog2;
    std::cout << "count = " << Dog::getcount() << '\n';//加上()，原先函数调用少了()
    {
        Dog dog3;
        std::cout << "count = " << Dog::getcount() << '\n';//加上()，原先函数调用少了()
    }
    std::cout << "count = " << Dog::getcount() << '\n';//加上()，原先函数调用少了()
        return 0;
}

跳转到最佳答案楼层

jhanker

改成下面这样就可以了！

#include <iostream>

class Dog
{
public:
    Dog();
    ~Dog();
 static int getcount();//此处加上 static
private:
   static int count;
};

int Dog::count = 0;

Dog::Dog()
{
    count += 1;
    std::cout << "add" << '\n';
}

Dog::~Dog()
{
    count -= 1;
    std::cout << "subtract" << '\n';
}

int Dog::getcount()
{
    return count;
}

int main()
{
    std::cout <<"Dog::getcount"  << '\n';
   Dog dog1; Dog dog2;
    std::cout << "count = " << Dog::getcount() << '\n';//加上()，原先函数调用少了()
    {
        Dog dog3;
        std::cout << "count = " << Dog::getcount() << '\n';//加上()，原先函数调用少了()
    }
    std::cout << "count = " << Dog::getcount() << '\n';//加上()，原先函数调用少了()
        return 0;
}

jhanker

std::cout << Dog::getcount << '\n';
std::cout << "count = " << Dog::getcount << '\n';
  std::cout << "count = " << Dog::getcount << '\n';
  std::cout << "count = " << Dog::getcount << '\n';
这几句代码都是有问题的。对于类本身无法调用getcount ()函数