[½»Á÷] C++дÎļþ

#include <cassert>
#include <iostream>
#include <fstream>

int main(int argc, char* argv[])
{
     double x[3]={0.0, 1.0, 0.0};
     double y[3]={0.0, 1.0, 2.0};

      std::ofstream write_output("Output.dat");

      assert(write_output.is_open()); //¼ì²éÎļþÊÇ·ñ´ò¿ª

      for(int i=0; i<3; i++)
      {
            write_output <<  x[i]  << "  " <<  y[i]  << "\n";
      }

      write_output.close();

      return 0;
}

#include <iostream>
#include <fstream>

int main(int argc, char* argv[])
{

     double x = 1.8364238;
     std::ofstream write_output("Output.dat");

     write_output.precision(3); // 3 λÓÐЧÊý×Ö
     write_output << x << "\n";

     write_output.precision(5); // 5 λÓÐЧÊý×Ö
     write_output << x << "\n";

     write_output.precision(10); // 10 λÓÐЧÊý×Ö
     write_output << x << "\n";
     write_output.close();

     return 0;

}