C++ 如何使<&书信电报；运算符，以便将对象的数据写入文件？

我有一个piggyBank类型的对象，我需要将这个对象的数据写入一个文件，然后读取它。我知道如何写入/读取文本文件，但如何使所有者“”过载；此->余额=0；此->断开=假；} id=++nrOfObjects； } PiggyBank:：PiggyBank（std:：字符串名称，int startBalance）{ {this->owner=name；this->balance=startBalance；this->break=false；} id=++nrOfObjects； } 字符串PiggyBank:：getOwnerName（）常量{ 返回此->所有者； } void PiggyBank:：setOwnerName（字符串名称）{ 此->所有者=名称； } bool PiggyBank:：isbreak（）{ 返回此->已损坏； } int PiggyBank:：getBalance（int和amount）{ 如果（！坏了）{ 金额=余额； 返回0； }否则{ 返回-1； } }

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非常简单。使插入器操作员过载。把这个写进你的课堂：

friend std::ostream& operator << (std::ostream& os, const PiggyBank& pb) {
    return os << pb.owner << . . .   // Whatever you want

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friend std:：ostream&operator您需要
谢谢。你的回答解决了我的问题。我只是有一个小问题：如果我想读取有关对象的书面数据，我是否也必须重载istream？没问题。是的，你也可以这样做。当您重载它时，您将能够读取文件并将信息存储回您的对象中。你也可以使用cin来做同样的事情。我很高兴我能提供帮助！非常感谢。你的回答对我帮助很大。
#include "PiggyBank.h"
#include "readWrite.h"
#include <string>
#include <iostream>
using namespace std;

int PiggyBank::nrOfObjects = 0; // outside constructor


PiggyBank::getNrOfObjects(){

    return nrOfObjects;

}

PiggyBank::PiggyBank(void){
    {this->owner="";this->balance=0;this->broken=false;}
     id = ++nrOfObjects;

}


PiggyBank::PiggyBank(std::string name, int startBalance){
     {this->owner=name;this->balance=startBalance;this->broken=false;}
     id = ++nrOfObjects;
}

string PiggyBank::getOwnerName() const{
    return this->owner;
}
void PiggyBank::setOwnerName(string name){
    this->owner = name;
}
bool PiggyBank::isBroken() {
    return this->broken;
}

int PiggyBank::getBalance(int & amount) {
    if(!broken){
        amount = balance;
        return 0;
    }else{
        return -1;
    }
}

friend std::ostream& operator << (std::ostream& os, const PiggyBank& pb) {
    return os << pb.owner << . . .   // Whatever you want

int main() {

    PiggyBank pb;

    if (std::ofstream os("FileName"); os) {
        os << pb << "\n";
    }

    return 0;
}

friend ostream& operator << (ostream& os, const PiggyBank& obj)
{
   // For example something like this
   os << "Information that you want to output to the file:\n";
   os << "Owner: " << obj.owner << "\n";
   return os;
}

PiggyBack obj;
ofstream fout("file.txt");

// also check to see if the file opened correctly
if(fout.fail())
{
   cout << "File failed to open\n";
   return 0;
}
fout << obj;
// now you have written the owner information onto the file as well as the message before it
// inside the  operator<< overload

// close the resource at the end
fout.close();

cout << obj; // will print to the console