friend ostream &operator <<(ostream &a,Point &b); protected: private: double x,y; }; // friend ostream& operator<<(ostream& o,A& another); ostream &operator <<(ostream &out,Point &b) //在类中声明的时候,可以是ostream &a,函数定义的时候也可以是ostream &out { out<<"("<<b.x<<...
friend std::ostream& operator<<(std::ostream& out, LinkedList& list) { // output something return out; } ... }; 或者在类之外定义它: std::ostream& operator<<(std::ostream& out, LinkedList& list) { // output something return out; } 顺便说一句:我建议您将第二个参数类型const LinkedList...
#include <cmath>#include<iostream>usingnamespacestd;classPoint {public: Point(doublexx,doubleyy) { x=xx; y=yy; }voidGetXY(); frienddoubleDistance(Point &a,Point &b); friend ostream&operator<<(ostream &a,Point &b);protected:private:doublex,y; };//friend ostream& operator<<(ostream& ...
c++中<<运算符重载 friend ostream operator<<(ostream& out ,A const& a){} 对"<<"运算符的重载。 一般我们用的"<<"只能输出整型、实型等普通类型。 要想输出类类型,则必须对"<<"进行重载,其中一个参数为类类型对象。 为了方便对对象内部数据的操作,设置为friend友元函数。 为了能达到cout<<对象<<对象...
#include <cmath> #include <iostream> using namespace std; class Point public: Point(double xx,double yy) x=xx; y=yy; void GetXY(); friend double Distance(Point &a,Point &b); friend ostream &operator <<(ostream &a,Point &b); ...
friendostream&operator<<(ostream&os,constParagraph&p){returnos<<p.to_str();} 如果用成员函数的...
友元函数从语法上看，它与普通函数一样，即在定义上和调用上与普通函数一样。#include"cmath"#include"iostream"using namespace std;class Point { public:Point(double xx,double yy){ x=xx;y=yy;} void GetXY();friend double Distance(Point&a,Point&b);protected:private:double x,y;};
()这样的代码 friend std::ostream& operator<<(std::ostream& os, const Student& stu); public: std::string m_id;//学号 std::string m_name;//姓名 int m_age;//年龄 std::string m_date;//生日 }; std::ostream & operator<<(std::ostream & os, const Student & stu) { //向os输出...
friend ostream &operator protected: private: double x,y; }; // friend ostream& operator ostream &operator { out return out; } void Point::GetXY() { //coutxy //cout cout } double Distance(Point &a,Point &b) { double length;
friend ostream &operator <<(ostream &a,Point &b); protected: private: double x,y; }; ostream &operator <<(ostream &out,Point &b) { out<<"("<<b.x<<","<<b.y<<")"<<endl; return out; } void Point::GetXY(){ //cout<<"("<<this->x<<","<<this->y<<")"<<endl; ...