我如何将输入到 txt 文件中的数据存储到数组中？

Question

我正在创建一个充当工资系统的程序，我在其中创建一个文件名并输入：ID (int)、pay (double)、小时数 (int) 和总工资 (double)。我将如何将我输入的数据放入文件并将它们放入数组并显示它们。稍后，我将需要对它们进行排序，因为我的 switch 语句中有案例。

#include <fstream>
#include <iostream>
#include <iomanip>
#include <string>    

using namespace std;


//Function prototypes

void getEmployeeInfo(int&, double&, int&); //EmployeeInfo prototype

double calcWage(double, int, double&); //calcWage prototype

void printWages(ofstream &, int, double, int , double); //print wages prototype

//Main function

int main(){

    int ID, hours, caseInput;
    double pay, gross;
    char input;
    ofstream outputFile;
    string filename;

    do {

    cout << "              Menu             " << endl;

    cout << "1. Calculate gross wages for employees" << endl;

    cout << "2. Display employees information to screen" << endl;

    cout << "3. Display information in order of ID" << endl;

    cout << "4. Display information in order of hourly rate" << endl;

    cout << "5. Display information in order of hours worked" << endl;

    cout << "6. Display information in order of wage" << endl;

    cout << "7. Quit the system" << endl;

    cout << "Enter your option -->  ";

    cin >> caseInput;
        switch (caseInput) {
            case 1: //Create file

            cout << "Enter the filename: ";

            cin >> filename;

            //open file

            outputFile.open(filename.c_str());

            outputFile << setw(10) << "ID" << setw (15) << "Pay" << setw(17) << "Hours"

                    << setw(11) << "Gross"<<endl;

            outputFile << "---------------------------------------------------------\n";

            do{

            getEmployeeInfo(ID, pay, hours);

            calcWage(pay, hours, gross);

            printWages(outputFile, ID, pay, hours, gross);

            cout << "Do you want to enter another employee's information? ";

            cin >> input;

            }

            while(input == 'y' || input == 'Y');



            //If user does not enter y, close file

            outputFile.close();

            cout << "The result is reported to the file " << 

            filename << "." << endl;

            break;



        case 2: 

            break;



        case 3: 

            break;


        case 4: 

            break;

        case 5: cout << "Thank you for using Math Tutor." << endl;

            break;


        case 6: cout << "Thank you for using Math Tutor." << endl;

            break;


        case 7: cout << "Thank you for using the Payroll System." << endl;

            break;


        default: cout << "Error. Enter a number 1-7." << endl;

    }

        }

        while(caseInput != 7);


return 0;

}

//Function to input employee info

void getEmployeeInfo(int &ID, double &pay, int &hours){

cout << "Enter an employee's information by the order of ID number, rate, hours: ";

cin >> ID >> pay >> hours;

while(ID < 0){

cout << "You must enter a non negative value. Try again!" << endl;

cin >> ID;

}

while(pay < 0){

cout << "You must enter a non negative value. Try again!" << endl;

cin >> pay;

}


while(hours < 0){

cout << "You must enter a non negative value. Try again!" << endl;

cin >> hours;

}


}


//Function calculates gross pay

double calcWage(double pay, int hours, double &gross){

    gross = pay * hours;

    return gross;

}

//Print function

void printWages(ofstream &outputFile, int ID, double pay, int hours, double gross){

  outputFile << setw(10)<< ID << setw(12) << "$" << setprecision(2) 

  << fixed << pay << setw(13) << hours 

  << setw(10) << "$" << fixed << gross << endl;

}

Answer 1

ifstream input("filename.txt");
copy(istreambuf_iterator<char>(input), istreambuf_iterator<char>(), ostreambuf_iterator<char>(cout));

此代码将从 txt 文件中读取数据并将其打印到屏幕上。您可以参考cppreference.com 了解所有组件的工作原理。

确保包含适当的标题。参考资料也会告诉您这一点。

Answer 2

我认为您可以将数据存储在 New 类中，然后首先将这些数据保存在 vecotr 中。像这样：

// declare a class with all your employee info in.
class Info
{
public:
    Info(int id, int hours, double pay)
    {
        this.ID = id;
        this.hours = hours;
        this.pay = pay;
        this.gross = pay*hours;
    }

    int ID;
    int hours;
    double pay;
    double gross;
}

vector<Info> vInfo; // save your data from your input or file

// if you want to sort your data
std::sort(vInfo.begin(), vInfo.end(), [ ](Info &a, Info &b){
    // you can change this depend on your order
    // return a.xxx < b.xxxx
    return a.ID < b.ID;
});
// then use the printWagesVec to print the data in your case 2,3,4,5,6
// change print function
int printWagesVec(vector<Info>& vInfo)
{
    cout << setw(10) << "ID" << setw (15) << "Pay" << setw(17) << "Hours"
    << setw(11) << "Gross"<<endl;

    cout << "---------------------------------------------------------\n";

    vector<Info>::iterator it = vInfo.begin();
    for(; it != vInfo.end(); it++)
    {
        cout << setw(10)<< it->ID << setw(12) << "$" << setprecision(2) 
        << fixed << it->pay << setw(13) << it->hours 
        << setw(10) << "$" << fixed << it->gross << endl;
    }

    return 0;
}