循环和奇怪的地址结果C ++

Question

I'm suppose to ask the user to enter the total cost of their purchase and the amount they paid for and provide the user their total change and how much change they get from ones, fives, tens, dimes, pennies etc.... but for some reason I cannot get the change to show the correct amount as I keep getting this change error (pic below) and it also keeps looping and looping. What am I doing wrong?

Thanks in advance for your help!

Driver.cpp

#include "MoneyChanger.h" 
#include <string>
#include <iostream>

using namespace std;

int main()
{
    MoneyChanger results;
    int twenties, tens, fives, ones, quarter, dimes, nickels, pennies;
    double purchase, given;
    string again = "yes";

    do{

    cout << "please enter total cost of purchase: $";
    cin >> purchase;

    cout << "\nplease enter amount given: $";
    cin >> given;

        //grabbing the bills and coins
        results.GetBills(&twenties, &tens, &fives, &ones);
        results.GetCoins(&quarter, &dimes, &nickels, &pennies);

        results.setData(purchase, given);

        //results
        cout << "Your change is: $" << results.getTotalChange() << "\n\n";
        cout << twenties << " Twenties" << endl;
        cout << tens << " Tens"  << endl;
        cout << fives << " Fives"  << endl;
        cout << ones << " Ones"  << endl;
        cout << quarter << " Quarters"  << endl;
        cout << dimes << " Dimes"  << endl;
        cout << nickels << " Nickels"  << endl;
        cout << pennies << " Pennies"  << endl;

        cout << "\n\nWould you like to calculate again?\nEnter yes or no\n";
        cin >> again;
    } while (again == "yes");


    cout << "Thank you for using this MoneyChanger!" << endl;

    return 0;
}

MoneyChanger.cpp

#include "MoneyChanger.h" 
#include <iostream> 
#include <iomanip> 
#include <string> 
#include <fstream> 
#include <cstdlib> 

using namespace std;

MoneyChanger::MoneyChanger()
{


}

void MoneyChanger::setData(double pp, double given)
{
    amountP = pp;
    amountG = given;
    CalcChange();
}
void MoneyChanger::CalcChange()
{
    while(totalChange >= 20){totalChange = totalChange-20; twenty++;}
    while(totalChange >= 10){totalChange = totalChange-10; ten++;}
    while(totalChange >= 5){totalChange = totalChange-5; five++;}
    while(totalChange >= 1){totalChange = totalChange-1; one++;}
    while(totalChange >= .25){totalChange = totalChange-.25; quarter++;}
    while(totalChange >= .10){totalChange = totalChange-.10; dime++;}
    while(totalChange >= .05){totalChange = totalChange-.05; nickel++;}
    while(totalChange >= .01){totalChange = totalChange-.01; penny++;}
}
double MoneyChanger::getTotalChange()
{
    totalChange = amountG - amountP;
    return totalChange;
}
void MoneyChanger::GetBills(int *twenties, int *tens, int *fives, int *ones)
{
    *twenties = twenty;
    *tens = ten;
    *fives = five;
    *ones = one;
    CalcChange();
}
void MoneyChanger::GetCoins(int *quarters, int *dimes, int *nickels, int *pennies)
{
    *quarters = quarter;
    *dimes = dime;
    *nickels = nickel;
    *pennies = penny;
    CalcChange();
 }

MoneyChanger.h

#ifndef H_MONEYCHANGER_H
#define H_MONEYCHANGER_H

using namespace std;

class MoneyChanger 
{ 
private: 
    double amountP, amountG, totalChange;
    int twenty, ten, five, one, change;
    int quarter, dime, nickel, penny;
    void CalcChange();
public:
    MoneyChanger();
    void setData(double pp, double given);
    double getTotalChange();
    void GetBills(int *twenties, int *tens, int *fives, int *ones);
    void GetCoins(int *quarters, int *dimes, int *nickels, int *pennies);
};
#endif

Answer 1

You're not initializing your member variables on construction.

Change this:

MoneyChanger::MoneyChanger()
{
}

To this:

MoneyChanger::MoneyChanger()
    : amountP(), amountG(), totalChange(),
      twenty(), ten(), five(), one(), change()
      quarter(), dime(), nickel(), penny()
{
}

To make this class remotely reusable, do the following as well:

void MoneyChanger::CalcChange()
{
    twenty = ten = five = one = 0;
    quarter = dime = nickel = penny = 0;

    while(totalChange >= 20){totalChange = totalChange-20; twenty++;}
    while(totalChange >= 10){totalChange = totalChange-10; ten++;}
    while(totalChange >= 5){totalChange = totalChange-5; five++;}
    while(totalChange >= 1){totalChange = totalChange-1; one++;}
    while(totalChange >= .25){totalChange = totalChange-.25; quarter++;}
    while(totalChange >= .10){totalChange = totalChange-.10; dime++;}
    while(totalChange >= .05){totalChange = totalChange-.05; nickel++;}
    while(totalChange >= .01){totalChange = totalChange-.01; penny++;}
}

I also see little point in invoking CalcChange() at the end of your Get functions. It should be at the beginning if anything.

Answer 2

• You should initialize enter code here`e all your variables before using them.
• It's safer to use reference to variables than pointer.

• you could call CalcChange() once at the end of setData() *totalChange should be initialized before calling setData : like :

  void MoneyChanger::setData(double pp, double given) { amountP = pp; amountG = given; totalChange = amountG - amountP;

   CalcChange(); 

  }