对静态变量 c++ 的未定义引用

Well, foo() is not static in your class, and you do not need to make it static in order to access static variables of your class.

您需要做的只是为您的静态成员变量提供一个定义:

What you need to do is simply to provide a definition for your static member variable:

class Helloworld {
  public:
     static int x;
     void foo();
};

int Helloworld::x = 0; // Or whatever is the most appropriate value
                       // for initializing x. Notice, that the
                       // initializer is not required: if absent,
                       // x will be zero-initialized.

void Helloworld::foo() {
     Helloworld::x = 10;
};

这篇关于对静态变量 c++ 的未定义引用的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持跟版网！