C++一个小程序，关于运算符重载，无法运行，不知道哪里出错。

Question

我在做一个练习，关于运算符重载的，写了一个重载+ 运算符的小程序，目的是输出K的实部和虚部，但无法运行，求前辈指导！谢谢大家。
代码如下：

#include "iostream"

using namespace std;

class Complex
{
private:
double real;
double image;

public:
Complex(double r = 0.0, double i = 0.0);
Complex operator + (const Complex &);

double getComplexReal();
double getComplexImage();

};

double Complex::getComplexReal()
{
return real;
}

double Complex::getComplexImage()
{
return image;
}

Complex Complex::operator+(const Complex & operand2)
{
return Complex(real + operand2.real, image + operand2.image);
}

int main()
{
Complex m(1.0,2.0),n(2.0,3.0),k;
k = m + n;
cout<<"K's real is:"<<k.getComplexReal()<<". and image is:"<<k.getComplexImage()<<endl;
}

Answer 1

很明显的错误，Complex构造函数只有声明没有定义啊， 其他的没有问题。
完整代码：

 #include "iostream"
using namespace std;

class Complex
{
private:
    double real;
    double image;

public:
    Complex(double r = 0.0, double i = 0.0): real(r), image(i) {}
    Complex operator + (const Complex &);
    double getComplexReal();
    double getComplexImage();
};


double Complex::getComplexReal()
{
    return real;
}

double Complex::getComplexImage()
{
    return image;
}

Complex Complex::operator+(const Complex & operand2)
{
    return Complex(real + operand2.real, image + operand2.image);
}

int main()
{
    Complex m(1.0,2.0),n(2.0,3.0),k;
    k = m + n;
    cout<<"K's real is:"<<k.getComplexReal()<<". and image is:"<<k.getComplexImage()<<endl;
}