我的 output 结果在 C++ 中为 0。 可能是什么问题

Question

#include <iostream> #include <stdio.h> #include <string> using namespace std; void getInput(string name, float weekly_Pay){ cout << "Please enter customer name" << endl; cin >> name; cout << "Enter weekly salary" << endl; cin >> weekly_Pay; } void calcFedTaxes(float weekly_Pay,float PIT_Rate, float SOSEC_Rate, float PIT, float SOSEC){ PIT = weekly_Pay * PIT_Rate; SOSEC = weekly_Pay * SOSEC_Rate; } void calcNetPay(float weekly_Pay, float PIT, float SOSEC, float weekly_Net_Pay){ weekly_Net_Pay = weekly_Pay - (PIT + SOSEC); } void displayInfo(string name, float PIT, float SOSEC, float weekly_Net_Pay){ cout << "Customer name is:" << name << endl; cout << "PIT is:" << PIT << endl; cout << "SOSEC is:" << SOSEC << endl; cout << "Weekly Pay is:" << weekly_Net_Pay << endl; } int main(){ char response = 'n'; string name =""; float weekly_Pay = 0.0; float weekly_Net_Pay = 0.0; const float PIT_RATE = (0.2); const float SOSEC_RATE = (0.08); float SOSEC = (0.0); float PIT = (0.0); do { getInput(name, weekly_Pay); calcFedTaxes (weekly_Pay, PIT_RATE, SOSEC_RATE, PIT, SOSEC); calcNetPay (weekly_Pay, PIT, SOSEC, weekly_Net_Pay); displayInfo (name, PIT, SOSEC, weekly_Net_Pay); cout << "Enter n or N to end:"; cin >> response; cout << endl; } while (!((response == 'n') || (response == 'N'))); }

Answer 1

Your functions are taking their output parameters by value , so they are acting on copies of the variables that main() passes to them. Any changes the functions make to the parameters are not reflected back to main() .

To do what you are attempting, you need to pass output parameters by reference instead:

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

using namespace std;

void getInput(string &name, float &weekly_Pay){
    cout << "Please enter customer name" << endl;
    cin >> name;
    cout << "Enter weekly salary" << endl;
    cin >> weekly_Pay;
}

void calcFedTaxes(float weekly_Pay, float PIT_Rate, float SOSEC_Rate, float &PIT, float &SOSEC){
    PIT = weekly_Pay * PIT_Rate; 
    SOSEC = weekly_Pay * SOSEC_Rate;
}

void calcNetPay(float weekly_Pay, float PIT, float SOSEC, float &weekly_Net_Pay){
    weekly_Net_Pay = weekly_Pay - (PIT + SOSEC);
}

void displayInfo(string name, float PIT, float SOSEC, float weekly_Net_Pay){
    cout << "Customer name is:" << name << endl;
    cout << "PIT is:" << PIT << endl;
    cout << "SOSEC is:" << SOSEC << endl;
    cout << "Weekly Pay is:" << weekly_Net_Pay << endl;
}

int main(){
    char response = 'n';
    string name =""; 
    float weekly_Pay = 0.0;
    float weekly_Net_Pay = 0.0;
    const float PIT_RATE = (0.2); 
    const float SOSEC_RATE = (0.08); 
    float SOSEC = (0.0);
    float PIT = (0.0);

    do {
        getInput(name, weekly_Pay);
        calcFedTaxes (weekly_Pay, PIT_RATE, SOSEC_RATE, PIT, SOSEC);
        calcNetPay (weekly_Pay, PIT, SOSEC, weekly_Net_Pay);
        displayInfo (name, PIT, SOSEC, weekly_Net_Pay);

        cout << "Enter n or N to end:";
        cin >> response;
        cout << endl;
    }
    while (!((response == 'n')  || (response == 'N')));
}

Live Demo