第九周项目1——附属类中的运算符重载（续）


在复数类中的运算符重载基础上

（1）再定义一目运算符 -，-c相当于0-c。

（2）定义Complex类中的<<和>>运算符的重载，实现输入和输出，改造原程序中对运算结果显示方式，使程序读起来更自然。

代码如下：

#include <iostream>
using namespace std;
class Complex
{
public:
Complex(){real=0;imag=0;}
Complex(double r,double i){real=r; imag=i;}
Complex operator-();
//实现输入，输出的运算符重载
friend ostream& operator <<(ostream& output,const Complex& c);
friend istream& operator >>(istream& input,Complex& c);
//实现加减乘除的运算符重载
friend Complex operator+(const Complex &c1, const Complex &c2);
friend Complex operator+(const double d, const Complex &c);
friend Complex operator+(const Complex &c, const double d);
friend Complex operator-(const Complex &c1, const Complex &c2);
friend Complex operator-(const double d, const Complex &c);
friend Complex operator-(const Complex &c, const double d);
friend Complex operator*(const Complex &c1, const Complex &c2);
friend Complex operator*(const double d, const Complex &c);
friend Complex operator*(const Complex &c, const double d);
friend Complex operator/(const Complex &c1, const Complex &c2);
friend Complex operator/(const double d, const Complex &c);
friend Complex operator/(const Complex &c, const double d);
private:
double real;
double imag;
};

//实现输出的运算符重载
ostream& operator <<(ostream& output,const Complex& c)
{
output<<"("<<c.real;
if(c.imag>=0) output<<"+";
output<<c.imag<<"i)";
return output;
}
//事先输入的运算符重载
istream& operator >>(istream& input,Complex& c)
{
int a,b;
char sign,i;
do
{
cout<<"input a Complex number(a+bi或a-bi):";
input>>a>>sign>>b>>i;
}
while(!((sign=='+'||sign=='-')&&i=='i'));
c.real=a;
c.imag=(sign=='+')?b:-b;
return input;
}
Complex Complex::operator-()
{
return (0-*this);
}
Complex operator+(const Complex &c1, const Complex &c2)
{
return Complex (c1.real+c2.real,c1.imag+c2.imag);
}
Complex operator+(const double d, const Complex &c)
{
return Complex (d+c.real,c.imag);
}
Complex operator+(const Complex &c, const double d)
{
return Complex (c.real+d,c.imag);
}
Complex operator-(const Complex &c1, const Complex &c2)
{
return Complex (c1.real-c2.real,c1.imag-c2.imag);
}
Complex operator-(const double d, const Complex &c)
{
return Complex (d-c.real,c.imag);
}
Complex operator-(const Complex &c, const double d)
{
return Complex (c.real-d,c.imag);
}
Complex operator*(const Complex &c1, const Complex &c2)
{
return Complex (c1.real*c2.real-c1.imag*c2.imag,c1.imag*c2.real+c1.real*c2.imag);
}
Complex operator*(const double d, const Complex &c)
{
return Complex (d*c.real,d*c.imag);
}
Complex operator*(const Complex &c, const double d)
{
return Complex (c.real*d,c.imag*d);
}
Complex operator/(const Complex &c1, const Complex &c2)
{
return Complex ((c1.real*c2.real+c1.imag*c2.imag)/(c2.real*c2.real+c2.imag*c2.imag),(c1.imag*c2.real-c1.real*c2.imag)/(c2.real*c2.real+c2.imag*c2.imag));
}
Complex operator/(const double d, const Complex &c)
{
return Complex (d/c.real,d/c.imag);
}
Complex operator/(const Complex &c, const double d)
{
return Complex (c.real/d,c.imag/d);
}

int main()
{
Complex c1,c2,c3;
double d=11;
cout<<"c1: "<<endl;;
cin>>c1;
cout<<"c2: "<<endl;
cin>>c2;
cout<<"c1="<<c1<<endl;
cout<<"c2="<<c2<<endl;
cout<<"d="<<d<<endl;
//cout<<"-c1="<
4000
;<(-c1);
c3=c1+c2;
cout<<"c1+c2="<<c3<<endl;
cout<<"c1+d="<<(c1+d)<<endl;
cout<<"d+c1="<<(d+c1)<<endl;
c3=c1-c2;
cout<<"c1-c2="<<c3<<endl;
cout<<"c1-d="<<(c1-d)<<endl;
cout<<"d-c1="<<(d-c1)<<endl;
c3=c1*c2;
cout<<"c1*c2="<<c3<<endl;
cout<<"c1*d="<<(c1*d)<<endl;
cout<<"d*c1="<<(d*c1)<<endl;
c3=c1/c2;
cout<<"c1/c2="<<c3<<endl;
cout<<"c1/d="<<(c1/d)<<endl;
cout<<"d/c1="<<(d/c1)<<endl;
return 0;

}

<img src="https://img-blog.csdn.net/20150509225150170?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQvd3l6OTUwNjIw/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center" alt="" />

总结：只要掌握了流插入和流提取运算符就不难解决问题了；