c++ - Sorting data from text file -

i need write program reads unknown number of numerical data text file array , uses sorting parameter sort numbers. i've been trying hours , can't program work

void sort(double &, double arr[], int s);  int main() {     fstream myfile;     int size, = 0;     const int n = 1000;     double x[n];      //reading data     myfile.open("data.txt");     if (myfile.fail())     {         cout << "error opening file" << endl;         exit(1);     }     while (!myfile.eof())     {         myfile >> x[i];         cout << x[i] << endl;         i++;     }     size = - 1;     cout << size << " number of values in file" << endl;     myfile.close();      = 0;     while (size > i)     {         cout << x[i] << endl;         i++;     }     //sorting     sort(x[n], x[n], size);     = 0;     while (size > i)     {         cout << x[i] << endl;         i++;     }     return 0; }  void sort(double &, double arr[], int s) {     bool swapped = true;     int j = 0;     int tmp;     while (swapped)      {         swapped = false;         j++;         (int = 0; < s - j; i++)          {             if (arr[i] > arr[i + 1])             {                 tmp = arr[i];                 arr[i] = arr[i + 1];                 &[i + 1] = &tmp;                 swapped = true;             }         }     } } 

while (!myfile.eof())  

is wrong, why iostream::eof inside loop condition considered wrong? end reading end of file. use instead

while (myfile >> x[i]) 

in case, can declare x std::vector, like

std::vector<double> x; 

read content vector, use

std::sort(x.begin(), x.end()); 

nothing more simple.

and complete c++ standard library solution, can use iterators , sorting algorithms, like

#include <algorithm> #include <iostream> #include <fstream> #include <iterator> #include <vector>  int main() {      std::fstream myfile("data.txt"); // should test if it's open correctly     std::vector<double> x(std::istream_iterator<double>(myfile), {});     std::sort(x.begin(), x.end());      for(const auto& elem: x)         std::cout << elem << " "; } 

you can map code above function. have no idea mean sorting parameter. if need able sort ascending/descending, may use std::less or std::greater (need #include <functional>), third parameter std::sort, like

std::sort(x.begin(), x.end(), std::greater<double>()); // sorts in descending order 

or write own comparator functor/lambda function.