实验3 多态性
实验课程名：面向对象程序设计（C++）
专业班级： 学号： 姓名： 实验时间： 实验地点： 指导教师：
3.1实验目的和要求 (1) 了解多态性的概念。 (2) 掌握运算符重载的基本方法。 (3) 掌握虚函数的定义和使用方法。 (4) 掌握纯虚函数和抽象类的概念和用法。
二、实验内容 一、构建一个复数类Complex，试对下列几个运算符进行重载：++，=，！=，+，-，==，其中要求要有成员重载形式和友元重载形式，而且，++运算符要求实现先加和后加两种形式。 该类定义原型说明： class complex { public: complex(double r=0,double i=0); complex &operator +(complex &c); complex operator -(complex &c); complex operator *(complex &c); friend complex operator /(complex &c1,complex &c2); friend int operator ==(complex &c1,complex &c2); friend int operator !=(complex &c1,complex &c2); //friend complex operator++(complex &c); complex operator++(); complex operator++(int); void disp(); private: double real; double imag; }; 实验代码如下： #include
imag=i; } complex operator +(complex &c); complex operator -(complex &c); complex operator *(complex &c); friend complex operator /(complex &c1,complex &c2); friend int operator ==(complex &c1,complex &c2); friend int operator !=(complex &c1,complex &c2); //friend complex operator++(complex &c); complex operator++(); complex operator++(int); void display(); double real; double imag; }; complex complex::operator +(complex &c) { complex c1; c1.real=real+c.real; c1.imag=imag+c.imag; return c1;
} complex complex::operator -(complex &c) { complex c1; c1.real=real-c.real; c1.imag=imag-c.imag; return c1; } complex complex::operator *(complex &c) { complex c1; c1.real=real*c.real-imag*c.imag; c1.imag=real*c.imag+imag*c.real; return c1; } complex operator /(complex &c1,complex &c2) { complex c; c.real=(c1.real*c2.real+c1.imag*c2.imag)/(c2.imag*c2.imag+c2.real*c2.real); c.imag=(c1.real*c2.imag-c1.imag*c2.real)/(c2.imag*c2.imag+c2.real*c2.real);
return c; } int operator ==(complex &c1,complex &c2) { if(c1.real==c2.real&&c1.imag==c2.imag) { return 1; } } int operator !=(complex &c1,complex &c2) { if(c1.real!=c2.real||c1.imag!=c2.imag) return 1; } complex complex::operator++() { return complex(real+1,imag); } complex complex::operator ++(int) { return complex(real,imag); real=real+1;