C ++文件io多行

Question

我正在嘗試一次從.txt文件讀取一行。 我想從每一行中獲取一個字符串和一個雙精度值。 每行都有一個名稱和薪水，用逗號分隔，例如

約翰·道爾（John Doyle），30000

伊恩·史密斯（Ian Smith），32000

等等

然后，我將更改這些值，然后將新值重新輸入到新的.txt文件中，例如

約翰·道爾，1100，31000，2300

伊恩·斯米特（Ian Smite），1300，32000，3000

我真的不確定我是否要正確解決問題。 我當前的代碼：

#include "pch.h"
#include <iostream>
#include <fstream>
#include <string>
using namespace std;

int main()
{
string name;
double data;

ifstream infile;
infile.open("worker.txt");

ofstream outfile;
outfile.open("worker2.txt");

infile >> name >> data;

while (!infile.fail())
{
    //do something with the name and salary read in
    double backPay = data * 7.6 / 100 / 2;
    double newAnnual = data * 7.6 / 100 + data;
    double newMonthly = data * 7.6 / 100 + data;
    double monthly = newMonthly / 12;

    // write inputted data into the file.
    outfile << backPay << ", " << newAnnual << ", " << monthly << ", " << 
endl;

    // then try another read
    infile >> name >> data;
}
outfile.close();
infile.close();
}

Answer 1

這是您要求的工作版本。

#include <iostream>
#include <fstream>
#include <string>
#include <stdlib.h>
using namespace std;

int main()
{
string name;
string tempData; //since getline function only accepts string params, you need this
double data;

ifstream infile;
infile.open("worker.txt");

ofstream outfile;
outfile.open("worker2.txt");

while (getline(infile, name, ',')) //firstly get the name as Johnny suggested
{
    getline(infile, tempData); // while on the same line, we can read the salary of that person
    data = atof(tempData.c_str()); //now convert the gotten string value into a double for calculations
    double backPay = data * 7.6 / 100 / 2;
    double newAnnual = data * 7.6 / 100 + data;
    double newMonthly = data * 7.6 / 100 + data;
    double monthly = newMonthly / 12;

    // write inputted data into the file.
    outfile << name << ", " << backPay << ", " << newAnnual << ", " << monthly << endl; //write the name and values as required into the output file  

}
outfile.close();
infile.close();
}