c++ - When writing to a file, only the last line saves to my output file -

im trying write file last line gets written file. i've tried opening , closing file outside loop nothing writes file

void getvalues (double totalenergy, double meanpowerconsumption, double maxpowerconsumption);  int main() {     double totalenergy, meanpowerconsumption, maxpowerconsumption;     getvalues(totalenergy, meanpowerconsumption, maxpowerconsumption);      return 0; }  void getvalues(double totalenergy, double meanpowerconsumption, double maxpowerconsumption) {     int x = 0;     int c = 0;     double p = 0;     int = 0;     ifstream infile;     infile.open("data.txt");      if (infile.fail())     {   cerr << "error opening file." << endl;         exit(1);     }      // declaring variables.     double power1, power2, time1, time2, totalpower, timeconstant, changeinpower, totaltime, time, coloumns;     double year, month, day, hour, minute, second, voltage, current, frequency;     double accumulatedpower=0;      while(!infile.eof())     {         infile >> year >> month >> day >> hour >> minute >> second >> voltage >> current >> frequency;          //should have taken account 'years','months' , 'days' throws calculations exponents.         time2 = ((3600*hour) + (minute *60) + second);          if (x==0)         {             timeconstant = 0;             time1 = 0;             totaltime = 0;         }         else         {             timeconstant = time2 - time1;             totaltime = totaltime + timeconstant;         }          //cout << "time1: " << time1 << endl;         //cout << "time2: " << time2 << endl;         //cout << "time constant: " << timeconstant<< endl;         //cout << "total time" << totaltime << endl;          power2 = voltage*current;          if (x==0)         {             power1 = 0;             changeinpower = 0;             totalpower = 0;             totalenergy = 0;             meanpowerconsumption = 0;         }         else         {             changeinpower = (power1 + power2)/2;             totalpower = totalpower + changeinpower;         }          // cout << "counter" << c << endl;         // assumed mean powerconsumption average of powers entered.         meanpowerconsumption = totalpower / c;          // testing variables.         //cout << "power1: " << power1 << endl;         //cout << "power2: " << power2 << endl;         //cout << "change in power: " << changeinpower << endl;         //cout << "total power: " << totalpower << endl;           //numerical integration:         totalenergy = totalenergy + (timeconstant*changeinpower);          //counter loop:          if (power2 > maxpowerconsumption)         {             maxpowerconsumption = power2;         }           accumulatedpower = accumulatedpower + power1;         time = time2 - time1;         p = p + time;           ofstream outfile;         outfile.open("byhour.txt");          (coloumns=0; p>=3599; coloumns++)         {             i++;             outfile << << " " << accumulatedpower/3600000 << endl;              accumulatedpower=0;             p=0;         }          outfile.close();          cout << "coloumns: " <<  << endl;         cout << "p value " << p << endl;         cout << "accumulated power" << accumulatedpower << endl;          cout << "the total energy is: " << totalenergy/3600000 << "kwh" << endl;         cout << "the mean power consumption is: " << meanpowerconsumption << endl;         cout << "the max power consumption is:" << maxpowerconsumption << endl;         cout << endl ;          c++;         x++;          time1 = time2;         power1 = power2;     }      ofstream outstats;     outstats.open("stats.txt");      outstats << totalenergy/3600000 << endl;     outstats << meanpowerconsumption << endl;     outstats << maxpowerconsumption << endl;      outstats.close(); } 

that's full code. tried taking out , putting in (open , close file). nothing has worked far

you opening , closing file in loop; based on default mode it's opening first position in file, each write opening file, writing start of file (likely overwriting there before), , closing it.

you should open file once, write out in loop, , close outside loop.