C++从公共静态方法访问私有静态成员？[副本]

Question

class MyClass
{
public:
    static int DoSomethingWithTheVar()
    {
        TheVar = 10;
        return TheVar;
    }
private:
    static int TheVar;
}

int Result = MyClass::DoSomethingWithTheVar();

undefined reference to `MyClass::TheVar'

Answer 1

对你问题的回答是肯定的！您刚刚错过了定义静态成员thevar:

int MyClass::TheVar = 0;

在cpp文件中。

就是尊重一个定义的规则。

// Myclass.h
class MyClass
{
public:
    static int DoSomethingWithTheVar()
    {
        TheVar = 10;
        return TheVar;
    }
private:
    static int TheVar;
};

// Myclass.cpp
#include "Myclass.h"

int MyClass::TheVar = 0;