声明复数类complx,该类中有两个私有变量real,image分别表示一个复数的实部和虚部，

很基础的类定义（若是C++的）class complex{ public: friend complex add(complex &x,complex &y); complex() { real = 0.0; imag = 0.0; } complex(float x, float y) { real = x; imag = y; } private: float real; float imag;};complex add(complex &x,complex &y){ return complex( x.real+y.real,x.imag+y.imag);}