#include<stdio.h>
#include<stdlib.h>
#include<iostream>
#include<string>
#include<conio.h>
#include<vector>
#include<utility> // pair 类
#include<cstddef> // sizeof
#include<list>//list类
#include<memory>  // anto_pr,自动new,delete
#include<algorithm>// copy()泛型算法
#include<iterator> //
using namespace std;
class Money{
public:
 Money();
 Money(double blance,double rate);
    void output1() const;
private:
 double _balance;
 double _rate;
 double _percent;
};
int main()
{  
 Money money1(100,2),money2;
 money1.output1();
 money2.output1();
 getch();
 return 0;
}
Money::Money():_balance(0.0),_rate(0.0)
{
}
Money::Money(double balance,double rate)
{  
 _balance = balance;
 _rate = rate;
}
void Money::output1()
{
 cout<<"_balance"<<endl;
 cout<<"_rate"<<endl;
}

#include <cstdlib>
#include <iostream>
using namespace std;

class Money
{
public:
    Money();
    Money(double blance,double rate);
  void output1() const;
private:
    double balance;
    double rate;
    double percent;
};

int main()
{  
    Money money1(100,2), money2;
    money1.output1();
    money2.output1();
   
    system("pause");
    return 0;
}
Money::Money(): balance(0.0), rate(0.0)
{
}
Money::Money(double balance, double rate)
{  
  this->balance = balance;
  this->rate = rate;
}
void Money::output1() const
{
  cout<<"balance: "<<balance<<endl;
  cout<<"rate: "<<rate<<endl;
}

我知道了,   忘记了在output1的定义里加 const

    因为我的粗心而浪费您的时间, 真对不起啊