c++ - C++ の初心者プログラマー。構造を関数に渡すのに役立ちます...?

Question

こんにちは初心者プログラマーです:] この質問をどのように表現するかさえわかりません。宿題に取り組んでいますが、作成したこの構造 (budget2) の値を変更できないようです。

このプログラムの目的は、最初の構造である Budget1 を表示し、ユーザーが Budget2 の値を入力した後で、予算 2 との違いを見つけることです。

デバッガによると、inputData 関数を使用して値を入力するときに予算 2 の値を変更していないため、showDiff 関数を実行すると、予算 1 から予算 2 のすべての値が差し引かれ、すべての合計が 0 として表示されます。

#include <iostream>
#include <windows.h>
#include <string>

using namespace std;


struct MonthlyBudget
{
    MonthlyBudget();
    double housing, utilities, householdExpenses, transportation, food, medical, insurance, entertainment, clothing, misc;

};


int main()
{
    HANDLE screen = GetStdHandle(STD_OUTPUT_HANDLE);
    COORD position;

    void inputData(struct MonthlyBudget data);
    void displayData(struct MonthlyBudget);
    void showDiff(struct MonthlyBudget, struct MonthlyBudget); 
    struct MonthlyBudget budget1, budget2;


    displayData(budget1);
    inputData(budget2);
    showDiff(budget1, budget2);




    system ("PAUSE");
    return 0;
}

MonthlyBudget::MonthlyBudget()
{
    housing = 500.00;
    utilities = 150.00;
    householdExpenses = 65.00;
    transportation = 50.00;
    food = 250.00;
    medical = 30.00;
    insurance = 100.00;
    entertainment = 150.00;
    clothing = 75.00;
    misc = 50.00;
}

void displayData(struct MonthlyBudget data)
{
    cout << "\n\tBudget\n\n\t";
    cout << "$" << data.housing << "\n\n\t";
    cout << "$" << data.utilities << "\n\n\t";
    cout << "$" << data.householdExpenses << "\n\n\t";
    cout << "$" << data.transportation << "\n\n\t";
    cout << "$" << data.food << "\n\n\t";
    cout << "$" << data.medical << "\n\n\t";
    cout << "$" << data.insurance << "\n\n\t";
    cout << "$" << data.entertainment << "\n\n\t";
    cout << "$" << data.clothing << "\n\n\t";
    cout << "$" << data.misc << "\n\n\t";

}

void inputData(struct MonthlyBudget data)
{

    HANDLE screen = GetStdHandle(STD_OUTPUT_HANDLE);
    COORD position;

    position.X = 15;
    position.Y = 3;
    SetConsoleCursorPosition(screen, position);

    cin >> data.housing;
    position.Y = 5;
    SetConsoleCursorPosition(screen, position);

    cin >> data.utilities;
    position.Y = 7;
    SetConsoleCursorPosition(screen, position);

    cin >> data.householdExpenses;
    position.Y = 9;
    SetConsoleCursorPosition(screen, position);

    cin >> data.transportation;
    position.Y = 11;
    SetConsoleCursorPosition(screen, position);

    cin >> data.food;
    position.Y = 13;
    SetConsoleCursorPosition(screen, position);

    cin >> data.medical;
    position.Y = 15;
    SetConsoleCursorPosition(screen, position);

    cin >> data.insurance;
    position.Y = 17;
    SetConsoleCursorPosition(screen, position);

    cin >> data.entertainment;
    position.Y = 19;
    SetConsoleCursorPosition(screen, position);

    cin >> data.clothing;
    position.Y = 21;
    SetConsoleCursorPosition(screen, position);

    cin >> data.misc;
    position.Y = 23;
    SetConsoleCursorPosition(screen, position);

}


void showDiff(struct MonthlyBudget data, struct MonthlyBudget data2)
{   
    HANDLE screen = GetStdHandle(STD_OUTPUT_HANDLE);
    COORD position;

    position.X = 20;
    position.Y = 3;
    SetConsoleCursorPosition(screen, position);

    cout << (data.housing - data2.housing);

    position.Y = 5;
    SetConsoleCursorPosition(screen, position);
    cout << (data.utilities - data2.utilities);


    position.Y = 7;
    SetConsoleCursorPosition(screen, position);
    cout << (data.householdExpenses - data2.householdExpenses);

    position.Y = 9;
    SetConsoleCursorPosition(screen, position);
    cout << (data.transportation - data2.transportation);

    position.Y = 11;
    SetConsoleCursorPosition(screen, position);
    cout << (data.food - data2.food);

    position.Y = 13;
    SetConsoleCursorPosition(screen, position);
    cout << (data.medical - data2.medical);

    position.Y = 15;
    SetConsoleCursorPosition(screen, position);
    cout << (data.insurance - data2.insurance);

    position.Y = 17;
    SetConsoleCursorPosition(screen, position);
    cout << (data.entertainment - data2.entertainment);

    position.Y = 19;
    SetConsoleCursorPosition(screen, position);
    cout << (data.clothing - data2.clothing);

    position.Y = 21;
    SetConsoleCursorPosition(screen, position);
    cout << (data.misc - data2.misc);

    position.X = 5;
    position.Y = 23;
    SetConsoleCursorPosition(screen, position);

}

私が間違っていることはよくわかりません。助けていただければ幸いです。どうもありがとうございました。

PS。私のコードはばかげているに違いないことはわかっています。