标签:重载运算符
假如我们有如下结构体声明:struct CarType
{
string maker;
int year;
float price;
};假定我们将mycar声明为该结构的一个对象,并且为该对象的所有数据成员赋值,然后我们编写下面的代码:
if(mycar>2000) cout<<"My car is more than 2000"<<endl;C++不知道如何处理这段代码,C++并不知道是将myCar中的year与2000比较还是myCar中的price与2000比较。我们必须通过编写一个C++能够执行的函数,告诉C++如何处理这一情况。
struct CarType
{
string maker;
int year;
float price;
//重载操作符 >
bool operator >(float number)
{
if(price>number)
return true;
return false;
}
};struct CarType
{
string maker;
int year;
float price;
//重载操作符 >
bool operator >(float number)
{
if(price>number)
return true;
return false;
}
bool operator >(CarType yourcar)
{
if(price>yourcar.price)
return true;
return false;
}
};现在我们定义了两个运算符>函数,调用哪一个函数取决于右操作数的类型,C++将试图进行匹配,如果无法匹配,编译器将会报错.if(2000 < mycar) cout<<"My car is more than 2000"<<endl;
struct CarType
{
string maker;
int year;
float price;
//重载操作符 >
bool operator >(float number)
{
if(price>number)
return true;
return false;
}
bool operator >(CarType yourcar)
{
if(price>yourcar.price)
return true;
return false;
}
};
bool operator <(int number ,CarType car)
{
if(car.price > number)
return true;
return false;
}#include <iostream>
#include <iomanip>
#include <string>
using namespace std;
struct CarType
{
string maker;
int year;
float price;
//重载操作符 >
bool operator >(float number)
{
if(price>number)
return true;
return false;
}
bool operator >(CarType yourcar)
{
if(price>yourcar.price)
return true;
return false;
}
};
bool operator <(int number ,CarType car)
{
if(car.price > number)
return true;
return false;
}
//结构和类之间的差别:1结构关键词struct 类关键词class 2.结构中默认公有,类中默认私有.
int main()
{
CarType mycar,yourcar;
mycar.maker="Mercedes";
mycar.year=2014;
mycar.price=45567.7155;
//属于同一个结构的对象之间能进行对象赋值
yourcar=mycar;
yourcar.price=10000;
cout<<"Your car is a:"<<mycar.maker<<endl;
cout<<fixed<<showpoint<<setprecision(2)<<"I will offer $"<<mycar.price-200<<" for your car"<<endl;
if(mycar>2000)
cout<<"My car is more than 2000"<<endl;
if(mycar>yourcar)
cout<<"My car is worth more than your car"<<endl;
if(2000 < mycar)
cout<<"My car is more than 2000"<<endl;
mycar.operator>(2000);;
mycar.operator>(yourcar);
operator<(2000,mycar);
return 0;
}原文链接:http://www.52coder.net/archives/2446.html版权所有.本站文章除注明出处外,皆为作者原创文章,可自由引用,但请注明来源.
标签:重载运算符
原文地址:http://blog.csdn.net/persever/article/details/45417735