初始化类中结构的值

Question

我在基本Polynomial类.h文件的私有部分中有以下代码:

private:
struct Term
{
    float coefficient;
    int power; // power of specific term
};
int degree; //total number of terms

我有Polynomial类的以下默认构造函数:

Polynomial::Polynomial()
{
    Polynomial.Term poly;
    poly.power = 0;
    poly.coefficient = 0;
    degree = 1;
}

我对如何访问结构中的术语以及结构外部的变量感到困惑.我试图谷歌这个,但找不到任何有用的东西.

编辑:重载输出操作员代码

ostream & operator << (ostream & outs, Polynomial & P)
{
    outs << P[0].poly.coefficient << "x^" << P[0].poly.power;
    for (int i=1; i<P.degree-1; i++)
    {
        if (P[i].poly.coefficient > 0)
            outs << "+";
        outs << P[i].poly.coefficient << "x^" << P[i].poly.power;
    }
    outs << endl;
}

Answer 1

您已在构造函数中声明了该变量.一旦执行离开构造函数,该变量就会被销毁.相反,您需要将变量添加到类声明中.如果您希望能够从任何类函数外部访问成员,您还需要公开变量和结构定义.

class Polynomial
{
public:
   struct Term
   {
      float coefficient;
      int power; // power of specific term
   };
   Term poly;
   int degree; //total number of terms

   Polynomial();
};

Polynomial::Polynomial()
{
    poly.power = 0;
    poly.coefficient = 0;
    degree = 1;
}